A
Adenine, one member of the A-T (adenine-thymine) base pair in DNA.
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A bands
The dark-staining anisotropic cross striations in the myofibrils of
muscle fibers, comprising regions of overlapping thick (myosin) and
thin (actin) filaments.
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A bile
Bile from the common duct.
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A cells
Alpha cells of pancreas or of anterior lobe of hypophysis.
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A chain
The shorter polypeptide component of insulin containing 21 amino
acyl residues, beginning with a glycyl residue (NH2-terminus);
insulin consists of an A chain linked to a B chain by two disulfide
bonds; the amino-acid composition of the A chain is a function of
species.
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A Course in Miracles
Form of spiritual psychotherapy based on A Course in Miracles,
whose three volumes-The Text, Workbook for Students, and Manual for
Teachers-comprise well over a thousand pages. "The Course"
originated in 1965, was completed in 1972, and was first published
(as a photocopy of typescript) in 1975. It allegedly is the fruit
of channeling from Jesus Christ to Helen Cohen Schucman
(1909-1981), a research psychologist at Columbia University.
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A fibers
Myelinated nerve fibers in somatic nerves, measuring 1-22 mcm in
diameter, conducting nerve impulses at a rate of 6-120 meters per
second.
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A wave
1. The initial negative deflection in the electroretinogram,
presumably reflecting retinal photoreceptor activity. 2. An atrial
deflection in an electrogram recorded from within the atrium of the
heart. 3. The first positive deflection of the atrial and venous
pulses due to atrial systole.
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A. baumannii
Abbreviation for Acinetobacter baumannii.
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A.B.C. process
Purification of water or deodorization of sewage by a mixture of
alum, blood, and charcoal.
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a.c.
Abbreviation for L. ante cibum, before a meal or ante cibos, before
meals.
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A.D.
Abbreviation for auris dextra [L.], right ear.
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A.S.
Abbreviation for auris sinistra [L.], left ear.
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A.U.
Abbreviation for auris utraque [L.], each ear or both ears.
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A/T cloning
Cloning of fragments in which the only overhanging (or
uncomplemented) ends are the A or T bases; occurs often in use of
specific enzymes to cut or make DNA fragments.
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A1C
A test that measures how much glucose has been sticking during the
past 3-4 months to hemoglobin, the substance in the red blood cells
that carries oxygen to the cells of the body.
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A33
A type of monoclonal antibody used in cancer detection or therapy.
Monoclonal antibodies are laboratory-produced substances that can
locate and bind to cancer cells.
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A33 monoclonal antibody
A type of monoclonal antibody used in cancer detection or therapy.
Monoclonal antibodies are laboratory-produced substances that can
locate and bind to cancer cells.
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AA
1. Abbreviation for amino acid, a building block of protein. 2.
Abbreviation for Alcoholics Anonymous.
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AA gradient
Abbreviation for alveolar arterial oxygen gradient. A calculation
that allows the clinician to estimate adequacy of oxygen transfer
from the alveolus to pulmonary capillary blood.
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AAA
Abbreviation for abdominal aortic aneurysm.
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Aaa disease
Endemic anemia of ancient Egypt, ascribed in the Papyrus Ebers to
intestinal infestation with ancylostoma; now called
ancylostomiasis.
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AAAS
Abbreviation for the American Association for the Advancement of
Science. Spoken of as the "triple A-S", the AAAS publishes the
weekly journal "Science".
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AABB
Abbreviation for the American Association of Blood Banks.
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AACP
Abbreviation for the American Association of Child Psychiatry.
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Aad
Abbreviation for α-aminoadipic acid.
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AAD
Abbreviation for the American Association of Dermatology.
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AAFP
Abbreviation for the American Association of Family Practice.
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Aagenaes syndrome
An idiopathic form of familial intrahepatic cholestasis associated
with lymphedema of the lower extremities.
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AAMC
Abbreviation for American Association of Medical Colleges.
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AAN
Abbreviation for the American Association of Neurology.
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AAO
Abbreviation for multiple organizations including American
Association of Ophthalmology, American Association of
Orthodontists, and American Academy of Otolaryngology.
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AAOS
Abbreviation for American Academy of Orthopedic Surgery.
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AAP
1. Abbreviation for alanine aminopeptidase. An enzyme that is used
as a biomarker to detect damage to the kidneys, and that may be
used to help diagnose certain kidney disorders. It is found at high
levels in the urine when there are kidney problems. 2. Water
element. 3. Abbreviation for multiple organizations including
American Academy of Pediatrics, American Academy of Pedodontics,
and American Academy of Periodontists.
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AAPMR
Abbreviation for the American Academy of Physical Medicine and
Rehabilitation.
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AAR
Abbreviation for antigen-antibody reaction.
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Aaron sign
In acute appendicitis, a referred pain or feeling of distress in
the epigastrium or precordial region on continuous firm pressure
over the McBurney point.
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Aarskog-Scott syndrome
An extremely rare genetic disorder that causes changes in the size
and shape of certain bones and cartilage in the body. The face,
fingers, and toes are most often affected.
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Aase syndrome
A rare, inherited disorder characterized by anemia with some joint
and skeletal deformities.
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Aase-Smith syndrome II
A genetic disorder that may be detected during early infancy and is
characterized by the presence of three bones (phalanges) within the
thumbs (triphalangeal thumbs) rather than the normal two and
abnormally reduced production of red blood cells (hypoplastic
anemia).
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AASH
Abbreviation for adrenal androgen-stimulating hormone.
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AAV
Abbreviation for adeno-associated virus.
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Ab
Abbreviation for antibody.
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AB
Abbreviation for abortion.
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Ab-
Prefix meaning "from, away from, off".
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Ab initio
From the beginning.
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Ab ovo
Latin expression for "from the beginning." Ab ovo literally means
"from the egg."
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Abadie sign of tabes dorsalis
Insensibility to pressure over the tendo achillis.
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Abampere
Electromagnetic unit of current equal to 10 absolute amperes; a
current that exerts a force of 2π dynes on a unit magnetic pole at
the center of a circle of wire 1 cm in radius.
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Abapical
Opposite the apex.
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Abapical pole
In an oocyte, the pole opposite the animal pole (vegetal pole).
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Abarelix
A drug used to reduce the amount of testosterone made in patients
with advanced symptomatic prostate cancer for which no other
treatment options are available. It belongs to the family of drugs
called gonadotropin-releasing hormone (GnRH) antagonists. Also
called Plenaxis.
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Abarognosis
Loss of ability to appreciate the weight of objects held in the
hand, or to differentiate among objects of different weights. When
the primary senses are intact, caused by a lesion of the
contralateral parietal lobe.
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Abasia
Inability to walk.
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Abasic
Refers to loss of pyrimidine sites in DNA.
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Abate
To lessen or decrease.
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Abatement
A diminution, decrease or easing.
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Abaxial
1. Lying outside the axis of any body or part. 2. Situated at the
opposite extremity of the axis of a part.
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Abbe condenser
A system of two or three wide-angle, achromatic, convex, and
planoconvex lenses that may be moved upward or downward beneath the
stage of a microscope, thereby regulating the concentration of
light (directly from a bulb or reflected from a mirror) that passes
through the material to be examined on the stage.
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Abbe flap
Triangular wedge of the lower lip (usually midline) transferred
into the upper lip and vascularized by the labial artery.
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Abbott artery
An anomalous artery arising from the posteromedial proximal
descending aorta, important during coarctation repair.
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Abbott stain for spores
Spores are stained blue with alkaline methylene blue; bodies of the
bacilli become pink with eosin counterstain.
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ABC leads
The leads for recording one kind of vectorcardiogram utilizing the
Arrighi triangle; supplanted by XYZ leads.
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ABC transporter proteins
A superfamily of carrier proteins that bind two highly conserved
ATP-binding cassettes and function in transporting peptides,
sugars, polysaccharides, and ions across the cell membrane.
Mutations in the gene that codes for one of these ABC transporter
proteins is believed to be responsible for cystic fibrosis.
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ABCD rating
A staging system for prostate cancer that uses ABCD. "A" and "B"
refer to cancer that is confined to the prostate. "C" refers to
cancer that has grown out of the prostate but has not spread to
lymph nodes or other places in the body. "D" refers to cancer that
has spread to lymph nodes or to other places in the body. Also
called the Jewett staging system or the Whitmore-Jewett staging
system.
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Abcoulomb
A unit of electrical charge equal to 10 coulombs. The charge that
passes over a given surface in 1 second if a current of 1 abampere
is flowing across the surface.
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Abdomen
The part of the body that contains the stomach, small intestine,
colon, rectum, liver, spleen, pancreas, kidneys, appendix,
gallbladder, and bladder.
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Abdomen, acute
The abrupt (acute) onset of abdominal pain.
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Abdominal
Having to do with the abdomen, which is the part of the body
between the chest and the hips that contains the pancreas, stomach,
intestines, liver, gallbladder, and other organs.
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Abdominal aneurysm
An aneurysm situated within the abdomen (belly). An aneurysm is a
localized widening (dilatation) of an artery, vein, or the heart.
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Abdominal angina
Intermittent abdominal pain, frequently occurring at a fixed time
after eating, caused by inadequacy of the mesenteric circulation
resulting from arteriosclerosis or other arterial disease.
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Abdominal aorta
The abdominal aorta is the final section of the aorta, the largest
artery in the body. It is a continuation of the thoracic aorta. It
begins at the diaphragm, and runs down to the point where it ends
(by splitting in two to form the common iliac arteries).
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Abdominal aortic (nerve) plexus
An autonomic plexus surrounding the abdominal aorta, directly
continuous with the thoracic aortic plexus superiorly and
continuing inferiorly to the bifurcation of the aorta as the
superior hypogastric plexus.
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Abdominal aortic aneurysm
An aneurysm is when a blood vessel becomes abnormally large or
balloons outward. The abdominal aorta is a large blood vessel that
supplies blood to the abdomen, the pelvis, and legs.
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Abdominal apoplexy
Mesenteric hemorrhage, thrombosis, or embolus involving the
mesenteric or abdominal blood vessels.
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Abdominal aura
Epileptic aura characterized by abdominal discomfort, including
nausea, malaise, pain, and hunger; some phenomena reflect ictal
autonomic dysfunction.
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Abdominal ballottement
Palpation of the abdomen to detect excessive amounts of fluid
(ascites) by causing organs to bob up and down in the fluid milieu.
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Abdominal cavity
The space between the abdominal wall and the spine.
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Abdominal compartment syndrome
A constellation consisting of cardiovascular, pulmonary, and renal
compromise produced by increased intraabdominal pressure from
bleeding (intraabdominal or retroperitoneal), ileus, peritonitis,
or insufflation
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Abdominal exploration
A surgical procedure that opens the abdomen (laparotomy) and
explores it for problems. During a laparotomy, treatment of
problems may also be administered.
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Abdominal film
X-ray images of the abdomen.
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Abdominal fissure
Congenital failure of the ventral body wall to close.
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Abdominal guarding
Tensing of the abdominal wall muscles to guard inflamed organs
within the abdomen from the pain of pressure upon them.
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Abdominal hernia
A hernia protruding through or into any part of the abdominal wall.
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Abdominal hysterectomy
Surgical removal of the uterus through an incision made in the
abdominal wall. As opposed to a vaginal hysterectomy.
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Abdominal hysteropexy
Attachment of the uterus to the anterior abdominal wall.
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Abdominal hysterotomy
Transabdominal incision into the uterus.
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Abdominal lymph nodes
The parietal and visceral lymph nodes of the abdomen, collectively.
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Abdominal migraine
1. Migraine in children accompanied by paroxysmal abdominal pain.
This must be distinguished from similar symptoms requiring surgical
attention. 2. A disorder that causes intermittent abdominal pain
and is believed to be related to migraine; abdominal migraine has
some of the features of migraine, there may be a strong family
history of migraine headaches, and the condition may be relieved by
sleep; however, a headache may not be present. The diagnosis
depends on excluding other causes of abdominal pain.
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Abdominal muscle deficiency syndrome
Partial or complete absence of the abdominal muscles so that the
outlines of the intestines are visible through the thin, lax,
protruding abdominal wall.
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Abdominal muscles
A large group of muscles in the front of the abdomen that assists
in the regular breathing movement and supports the muscles of the
spine while lifting and keeping abdominal organs such as the
intestines in place.
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Abdominal myomectomy
Removal of a myoma of the uterus through an abdominal incision.
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Abdominal nephrectomy
Transperitoneal removal of the kidney by an incision through the
anterior abdominal wall.
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Abdominal ostium of uterine tube
The fimbriated or ovarian extremity of an oviduct.
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Abdominal pain
Pain in the belly (the abdomen).
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Abdominal part of esophagus
The portion of the esophagus from where it passes through the
diaphragm to where it enters the stomach.
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Abdominal part of pectoralis major
Portion of pectoralis major originating from the rectus sheath.
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Abdominal part of peripheral autonomic plexuses and ganglia
Portion of the autonomic nervous system (networks composed largely
of autonomic nerve fibers-but also including visceral afferent
fibers-and ganglia associated with blood vessels and organs) that
occur both retro- and intraperitoneally in the abdominal cavity.
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Abdominal part of thoracic duct
The part of the thoracic duct between the cisterna chyli and the
aortic hiatus of the diaphragm.
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Abdominal part of ureter
The part of the ureter between the renal pelvis and the brim of the
pelvis.
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Abdominal pool
The volume of blood within the abdomen.
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Abdominal pregnancy
The implantation and development of the ovum in the peritoneal
cavity, usually secondary to an early rupture of a tubal pregnancy;
very rarely, primary implantation may occur in the peritoneal
cavity. The blastocyst commonly implants in the rectouterine pouch
of peritoneum.
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Abdominal pressure
Pressure surrounding the bladder; estimated from rectal, gastric,
or intraperitoneal pressure.
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Abdominal pulse
The soft, compressible aortic pulse occurring in certain abdominal
disorders.
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Abdominal reflexes
Contraction of the muscles of the abdominal wall on stimulation of
the skin (superficial a. reflexs) or tapping on neighboring bony
structures (deep a. reflexes).
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Abdominal regions
Topographic divisions of the abdomen, as bounded by the vertical
midclavicular lines and the horizontal transpyloric and
interspinous (transtubercular) lines.
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Abdominal respiration
Breathing effected mainly by the action of the diaphragm.
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Abdominal rigidity
Abnormal muscle tension or inflexibility of the abdomen, detected
when touched or pressed.
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Abdominal sac
The part of the embryonic celom that becomes the abdominal cavity.
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Abdominal salpingectomy
Removal of one or both uterine tubes through an abdominal incision.
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Abdominal salpingotomy
Incision into the uterine tube through an opening in the abdominal
wall.
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Abdominal tap
A procedure in which a needle is inserted through the abdominal
wall to remove fluid from the abdomen. Normally, the abdomen
contains only a small amount of fluid. In certain conditions, large
amounts of fluid can accumulate in the abdomen.
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Abdominal testis
An undescended testis that has never descended from the
retroperineal/abdominal origin through the internal inguinal ring.
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Abdominal wall fat pad biopsy
A procedure that involves removing a small portion of the abdominal
wall fat pad. The procedure is done most often to test for
amyloidosis.
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Abdomino-
Combining form indicating the abdomen, abdominal.
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Abdominocardiac reflex
Mechanical stimulation (usually distention) of abdominal viscera
causing changes (usually a slowing) in the heart rate or the
occurrence of extrasystoles.
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Abdominocentesis
Paracentesis of the abdomen.
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Abdominogenital
Relating to the abdomen and the genital organs.
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Abdominopelvic
Relating to the abdomen and pelvis, especially the combined
abdominal and pelvic cavities.
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Abdominopelvic cavity
The combined and continuous abdominal and pelvic cavities.
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Abdominopelvic splanchnic nerves
Visceral branches of the sympathetic trunks conveying presynaptic
sympathetic fibers to and visceral afferent fibers from the
prevertebral ganglia and paraaortic/hypogastric plexuses for the
innervation of viscera located below the diaphragm. The greater,
lesser, lowest, lumbar, and sacral splanchnic nerves belong to this
group.
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Abdominoperineal
Relating to both abdomen and perineum, as in abdominoperineal
resection of the rectum.
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Abdominoperineal resection
A surgical cancer treatment involving resection of the lower
sigmoid colon, rectum, anus, and surrounding skin and formation of
a sigmoid colostomy; performed as a synchronous or sequential
transabdominal and perineal procedure.
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Abdominoplasty
An operation performed on the abdominal wall for cosmetic purposes.
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Abdominoscrotal
Relating to the abdomen and the scrotum.
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Abdominothoracic
Relating to both the abdomen and the thorax.
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Abdominothoracic arch
A bell-shaped line defined by the lower end of the sternum and the
costal arches on each side, constituting a boundary line between
the anterolateral portions of the thoracic and abdominal walls.
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Abdominovaginal
Relating to both the abdomen and the vagina.
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Abdominovaginal hysterectomy
A combined vaginal and abdominal surgical dissection that allows
partial or complete removal of vagina, vulva, rectum, and perineum
(abdominoperineal approach) as well as pelvic organs; usually done
in cases of advanced pelvic cancer.
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Abdominovesical
Relating to the abdomen and urinary bladder, or to the abdomen and
gallbladder.
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Abducens nucleus
A group of motor neurons in the lower part of the pons, innervating
the ipsilateral lateral rectus muscle of the eye; unique among
motor cranial nerve nuclei in that it consists of two distinct
populations of neurons: neurons that give rise to fibers forming
the abducens nerve root and those internuclear neurons the
processes of which cross the midline, ascend in the opposite medial
longitudinal fasciculus, and terminate on specific oculomotor
neurons; considered a primary center for mechanisms controlling
conjugate horizontal gaze.
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Abducent
Abducting; drawing away, especially away from the median plane.
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Abducent nerve
A small motor nerve that has one task: to supply a muscle called
the lateral rectus muscle that moves the eye outward.
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Abduct
To move away from the median plane.
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Abduction
To move a limb or some other body part away from the midline of the
body.
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Abductor digiti minimi of foot
Muscle of first layer of plantar muscles; origin, lateral, and
medial processes of calcaneal tuberosity; insertion, lateral side
of proximal phalanx of fifth toe; action, abducts, and flexes
little toe; nerve supply, lateral plantar nerve.
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Abductor digiti minimi of hand
Superficial hypothenar muscle of palm; origin, pisiform bone, and
pisohamate ligament; insertion, medial side of base of proximal
phalanx of the little finger; action, abducts, and flexes little
finger; nerve supply, deep branch of ulnar.
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Abductor hallucis
Muscle of third layer of plantar muscles; origin, medial process of
calcaneal tuberosity, flexor retinaculum, and plantar aponeurosis;
insertion, medial side of proximal phalanx of great toe; action,
abducts great toe; nerve supply, medial plantar.
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Abductor muscle
Any muscle used to pull a body part away from the midline of the
body. For example, the abductor leg muscles serve to spread the
legs. The opposite of "abductor" is "adductor."
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Abductor pollicis brevis
Superficial thenar muscle origin, tubercle of trapezium, and flexor
retinaculum; insertion, lateral side of proximal phalanx of thumb;
action, abducts thumb; nerve supply, median.
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Abductor pollicis longus
Outcropping muscle of posterior compartment of forearm; origin,
interosseous membrane, and posterior surfaces of radius and ulna;
insertion, lateral side of base of first metacarpal bone; action,
abducts and assists in extending thumb; nerve supply, radial.
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Abductor spasmodic dysphonia
A breathy form of spasmodic dysphonia caused by long and excessive
vocal fold opening for voiceless phonemes extending into vowels.
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Abegg rule
The tendency of the sum of the maximum positive and negative
valences of a particular element to equal 8; C may have a valence
of +4 and −4, O of +6 and −2. Sometimes loosely stated as all atoms
have the same number of valences, a consequence of the tendency of
valence electron shells to be filled to 8.
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Abell-Kendall method
A standard reference method for estimation of total serum
cholesterol involving saponification of cholesterol ester by
hydroxide, extraction with petroleum ether, and color development
with acetic anhydride-sulfuric acid; the method avoids interference
by bilirubin, protein, and hemoglobin.
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Abelson murine leukemia virus
A retrovirus belonging to the Type C retrovirus group subfamily
(family Retroviridae) that is associated with leukemia and induces
in vitro transformation of certain mouse cells.
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Abembryonic
The area of the blastocyst opposite the region where the
embryoblast (early embryo) is located
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Abembryonic pole
The pole of the blastocyst opposite the embryonic pole where the
embryoblast (primordial embryo) is located.
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Abenteric
A nearly obsolete term meaning away from the intestine, said of a
morbid process occurring elsewhere that would normally occur in the
intestine.
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Abernethy fascia
A layer of subperitoneal areolar tissue in front of the external
iliac artery.
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Aberrant
1. Differing from the usual or norm; in botany or zoology, used for
certain atypical individuals in a species; abnormal. 2. Wandering
off; used to describe certain ducts, vessels, or nerves that
deviate from the usual or normal course or pattern.
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Aberrant artery
Artery having an unusual origin or course.
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Aberrant bile ducts
Small ducts occasionally present in the ligaments of the liver or
originating from the surface of the liver.
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Aberrant bundles
A group, or groups, of fibers from the corticobulbar or
corticonuclear tract, directed to each of the motor nuclei of the
cranial nerves.
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Aberrant complex
An anomalous electrocardiographic complex, more specifically an
abnormal ventricular complex caused by abnormal intraventricular
conduction of a supraventricular impulse.
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Aberrant ductules
The superior or inferior diverticula of the epididymis.
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Aberrant ganglion
A collection of nerve cells sometimes found on a posterior spinal
nerve root between the spinal ganglion and the spinal cord.
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Aberrant goiter
Enlargement of a supernumerary thyroid gland.
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Aberrant hemoglobin
A mutant Hb that functions abnormally.
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Aberrant hepatic artery
Relatively common accessory or replaced right or left hepatic
artery; although many varieties exist, the most common source of an
aberrant right hepatic artery is the superior mesenteric artery;
the most common source of an aberrant left hepatic artery is the
left gastric artery.
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Aberrant regeneration
Misdirected regrowth of nerve fibers seen, for example, after
oculomotor nerve injury.
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Aberrant ventricular conduction
Abnormal intraventricular conduction of a supraventricular beat,
especially where surrounding beats are normally conducted.
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Aberration
A deviation, or irregularity. For example, a mental aberration is a
significant deviation from normal mental activity. A chromosome
aberration is a an abnormality in chromosome number or structure.
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Aberrometer
An instrument for measuring optic aberration or any error in
experimentation.
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Abetalipoproteinemia
A disorder characterized by an absence of low-density
β-lipoprotein, presence of acanthocytes in blood, retinal
pigmentary degeneration, malabsorption, engorgement of upper
intestinal absorptive cells with dietary triglycerides, and
neuromuscular abnormalities; autosomal recessive inheritance,
caused by mutation in the gene-encoding microsomal triglyceride
transfer protein (MTP) on chromosome 4q.
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Abeyance
A state of temporary cessation of function.
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Abfarad
Electromagnetic unit of capacity equal to 109 farads.
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Abfraction
To break away.
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Abfraction lesion
Loss of tooth structure, usually in a wedge-shaped pattern in the
cervical area of the tooth, attributed to flexure and fatigue in an
area away from the point of loading (usually cervical).
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ABG
Abbreviation for arterial blood gas reading. Blood gas analyses are
performed to evaluate the adequacy of ventilation, oxygenation,
oxygen-carrying capacity of the blood, and acid-base levels.
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Abhenry
Electromagnetic unit of inductance equal to 10−9 henry.
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Abhyanga
Ayurvedic "rejuvenating cure" that is a secondary part of
panchakarma. Abhyanga is a "very complete massage" with medicated
(herbal) oil. Practitioners supposedly formulate the medicated oil
to one's "constitutional type."
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ABI
Abbreviation for ankle-brachial index.
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Ability
The physical, mental, or legal competence to function.
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Abiotic
1. Incompatible with life. 2. Without life.
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Abiotrophy
An age-dependent manifestation of a genetically determined trait.
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Abirritation
Obsolete term for diminution or abolition of irritability in a
part.
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Abjad
Sufi system of numerology.
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Abl
An oncogene found in the Abelson strain of mouse leukemia virus;
involved in the Philadelphia chromosome translocation in chronic
granulocytic leukemia.
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Ablastemic
Not germinal or blastemic.
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Ablastin
An antibody that seems to inhibit reproduction of trypanosomes;
found in rats infected with Trypanosoma lewisi.
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Ablate
To remove, usually by cutting. During surgery a tumor may be
ablated.
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Ablation
1. Elimination or removal. 2. Surgical excision or amputation of a
body part or tissue. In medicine, the removal or destruction of a
body part or tissue or its function. Ablation may be performed by
surgery, hormones, drugs, radiofrequency, heat, or other methods.
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ABLB
Abbreviation for alternate binaural loudness balance (test).
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Ablepharia
Congenital absence of the eyelids.
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Abluent
1. Cleansing. 2. Anything with cleansing properties.
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Ablution
An act of washing or bathing.
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Abnerval
Away from a nerve; denoting specifically a current of electricity
passing through a muscular fiber in a direction away from the point
of entrance of the nerve fiber.
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Abneural
Away from the neural axis.
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Abnormal
Not normal. An abnormal lesion or growth may be cancerous,
premalignant (likely to become cancer), or benign.
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Abnormal cleavage of cardiac valve
Congenital malformation of a valve leaflet with a defect extending
from the free margin.
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Abnormal neurulation
Failure of closure of part(s) of the neural tube that produces
neural tube defects such as spinal bifida cystica.
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Abnormal occlusion
An arrangement of the teeth that is not considered to be within the
normal range of variation.
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Abnormality
1. The state or quality of being abnormal. 2. An anomaly,
deformity, malformation, impairment, or dysfunction.
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ABO
Symbol for blood group systems, under system.
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ABO blood groups
The major blood group system. A person can be blood type A, B, AB,
or O.
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ABO hemolytic disease of the newborn
Erythroblastosis fetalis resulting from maternal-fetal
incompatibility with respect to an antigen of the ABO blood group;
the fetus possesses A or B antigen (or both), which is lacking in
the mother, and the mother produces immune antibody, which causes
hemolysis of fetal erythrocytes.
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Abohm
Electromagnetic unit of resistance equal to 10−9 ohm.
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Aborad
In a direction away from the mouth; opposite of orad.
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Abort
1. The expulsion of an embryo or fetus before it is viable. 2. The
removal of the products of conception prematurely. 3. To arrest a
disease in its earliest stages. 4. To arrest any action or process
before its normal completion.
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Aborted systole
A loss of the systolic beat in the radial pulse through weakness of
the ventricular contraction.
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Abortifacient
1. Producing abortion. 2. An agent that produces abortion.
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Abortion
In medicine, the premature exit of the products of conception from
the uterus. A spontaneous abortion is a miscarriage. The
miscarriage of three or more consecutive pregnancies is termed
habitual abortion.
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Abortion, habitual
The miscarriage of three or more consecutive pregnancies. Recurrent
abortion can be identically defined as three or more miscarriages
(spontaneous abortions) with no intervening pregnancies. Habitual
or recurrent abortion is a form of infertility.
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Abortion, multiple
Couples who have had two or more miscarriages (spontaneous
abortions) have about a 5% chance that one member of the couple is
carrying a chromosome translocation responsible for the
miscarriages.
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Abortion, recurrent
The miscarriage of three or more consecutive pregnancies. Recurrent
abortion can be identically defined as three or more miscarriages
(spontaneous abortions) with no intervening pregnancies. Habitual
or recurrent abortion is a form of infertility.
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Abortionist
One who performs an abortion.
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Abortive
Not reaching completion; said of an attack of a disease subsiding
before it has fully developed or completed its course.
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Abortive transduction
Transduction in which the genetic fragment from the donor bacterium
is not integrated in the genome of the recipient bacterium, and,
when the latter divides, is transmitted to only one of the daughter
cells.
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Abortus
Any product (or all products) of an abortion; a human fetus whose
weight is less than 0.5 kilogram when removed or expelled from the
mother's body.
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Aboukra
Purportedly, an ancient Egyptian "healing art" that strengthens and
balances the body's "natural energy fields" and "meridians."
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ABP
Abbreviation for androgen binding protein.
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ABPA
Abbreviation for allergic bronchopulmonary aspergillosis.
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ABR
Abbreviation for auditory brainstem response.
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Abrachia
Congenital absence of arms.
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Abrachiocephaly
Congenital absence of arms and head.
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Abrade
1. To wear away by mechanical action. 2. To scrape away part or all
of the surface layer from a part.
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Abrahams sign
1. Earlier appreciation of abnormal pulmonary auscultatory signs
over the distal clavicle than at the apex, suggesting apical
tuberculosis. 2. Diminished percussive resonance over the pulmonary
apex in advancing tuberculosis.
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Abrams heart reflex
A contraction of the myocardium when the skin of the precordial
region is irritated.
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Abrasion
1. An abrasion or "excoriation" is a wearing away of the upper
layer of skin as a result of applied friction force. 2. In
dentistry, an "abrasion" is the wearing away of the tooth
substance.
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Abrasive
1. Causing abrasion. 2. Any material used to produce abrasions. 3.
A substance used in dentistry for abrading, grinding, or polishing.
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Abrasive strip
A ribbonlike piece of linen with bonded abrasive particles on one
side; used in dentistry to contour and polish proximal surfaces of
restorations.
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Abreaction
In freudian psychoanalysis, an episode of emotional release or
catharsis associated with the conscious recollection of repressed
unpleasant experiences.
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Abrin
A phytotoxin from jequirity seeds or Indian glycyrrhiza, the red
seeds (Abrus precatorius); used in ophthalmology.
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Abruptio
Premature separation of the placenta from the wall of the uterus.
Abruption is a potentially serious problem both for the mother and
baby. Also called abruptio placentae.
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Abruption
Premature detachment of a normally situated placenta.
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Abrus
A genus of leguminous plants.
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Abs. feb.
Abbreviation for L. absente febre, when fever is absent.
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Abscess
A localized collection of pus and liquefied tissue in a cavity.
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Abscess cavity
A cavity resulting from necrotizing infection, recognized
radiologically by its gas content.
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Abscess, peritonsillar
A persistent collection of pus behind the tonsil.
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Abscess, skin
Medical term for a common boil.
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Abscessed tooth
A sac of pus (infected material) in a tooth or the gums that
results from bacterial infection.
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Abscissa
In a plane cartesian coordinate system, the horizontal axis (x).
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Abscission
Cutting away.
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Absconsio
A recess, cavity, or depression; used especially in osteology to
denote a bony cavity that accommodates the head of another bone.
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Abscopal
Denoting the effect that irradiation of a tissue has on remote
nonirradiated tissue.
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Abscopal effect
A reaction produced following irradiation but occurring outside the
zone of actual radiation absorption.
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Absence
Paroxysmal attacks of impaired consciousness, occasionally
accompanied by spasm or twitching of cephalic muscles.
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Absence seizure
A seizure characterized by impaired awareness of interaction with,
or memory of, ongoing events external or internal to the person.
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Absent healing
1. Alleged treatment of a patient not in the practitioner's
vicinity through magic, meditation, prayer, "spirit doctors," or
telepathy. 2. A form of faith healing that supposedly involves the
projection of "positive healing energy." Also known as absentee
healing, distance healing, distant healing, remote healing, and
teleotherapeutics.
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Absidia
A genus of fungi (family Mucoraceae) commonly found in nature.
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Absinthe
A liquor consisting of 60-75% ethanol flavored with absinthium,
anise, fennel, and other herbs.
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Absinthin
A bitter principle obtained from absinthium.
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Absinthium
The dried leaves and tops of Artemisia absinthium (family
Compositae).
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Absolute
1. A preparation in perfumery in which the fragrance principles of
flowers are concentrated through alcohol extraction. 2. A highly
concentrated, viscous, semi solid, or solid perfume material.
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Absolute agraphia
Agraphia in which not even unconnected letters can be written.
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Absolute alcohol
1. 100% alcohol, water having been removed. 2. Alcohol with a
minimum admixture of water, at most 1%.
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Absolute CD4 count
The number of "helper" T-lymphocytes in a cubic millimeter of
blood. With HIV, the absolute CD4 count declines as the infection
progresses. The absolute CD4 count is frequently used to monitor
the extent of immune suppression in persons with HIV. Also called a
T4 count.
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Absolute cell increase
An actual increase in one of the types of leukocytes, the absolute
number of leukocytes in 1 cu mm of blood being obtained by
multiplying the total leukocyte count by the percentage of the cell
types in question.
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Absolute dehydration
Actual water deficit as measured by a difference from the normal or
from a given water content.
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Absolute glaucoma
The final stage of blindness in glaucoma.
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Absolute hemianopia
Hemianopia in which the affected field is totally insensitive to
all visual stimuli.
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Absolute humidity
The mass of water vapor actually present per unit volume of gas or
air.
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Absolute hydration
Actual water excess as measured by a difference from the normal or
from a given water content.
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Absolute hyperopia
Manifest hyperopia that cannot be overcome by an effort of
accommodation.
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Absolute intensity threshold acuity
The minimum level of perceptible light.
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Absolute leukocytosis
An actual increase in the total number of leukocytes in the
circulating blood, as distinguished from a relative increase (such
as that observed in dehydration).
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Absolute oils
Essential oils that are obtained by the removal of insoluble
compounds from concrete oils.
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Absolute pressure
Pressure measured with respect to zero pressure.
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Absolute refractory period
The period following excitation during which no response is
possible regardless of the intensity of the stimulus.
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Absolute risk
Probability that a specified event will occur in a specified
population, in contrast to the relative risk of the event.
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Absolute risk approach
A disease-control method based on the observation that proportional
reduction in risk for given absolute reductions in risk factors is
independent of the level of the risk factor: for instance reducing
systolic blood pressure by 10 mmHg produces the same percentage
reduction in risk of heart attack or stroke at all levels of
pretreatment blood pressure.
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Absolute scale
Obsolete term for Kelvin scale.
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Absolute scotoma
A scotoma in which there is no perception of light.
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Absolute system of units
A system of measurement based on absolute units accepted as being
fundamental (length, mass, time) and from which other units (force,
energy or work, power) are derived.
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Absolute temperature
Temperature reckoned in degrees Kelvin from absolute zero.
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Absolute terminal innervation ratio
The number of motor endplates divided by the number of terminal
axons related to them.
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Absolute threshold
The lowest limit of any perception.
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Absolute unit
A unit the value of which is constant regardless of place or time
and does not derive from nor depend on gravitation.
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Absolute viscosity
Force per unit area applied tangentially to a fluid, causing unit
rate of displacement of parallel planes separated by a unit
distance.
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Absolute zero
The lowest possible temperature, that at which the form of
translational molecular motion constituting heat is assumed no
longer to exist, determined as −273.15°C or 0 kelvin.
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Absorb
1. To take in by absorption. 2. To reduce the intensity of
transmitted light.
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Absorbable gelatin film
A thin, sterile, nonantigenic, absorbable, water-insoluble, thin
sheet of gelatin prepared by drying a gelatin-formaldehyde solution
on plates.
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Absorbable gelatin sponge
A sterile, absorbable, water-insoluble, gelatin-based sponge, used
to control capillary bleeding in surgical operations; it is left in
situ and absorbed within 4-6 weeks.
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Absorbable surgical suture
A surgical suture material prepared from a substance that can be
dissolved by body tissues and is therefore not permanent.
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Absorbance
Spectrophotometry log of the ratio of the radiant power of the
incident radiation to the radiant power of the transmitted
radiation.
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Absorbed dose
The amount of energy absorbed per unit mass of irradiated material
at the target site.
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Absorbefacient
1. Causing absorption. 2. Causing absorption.
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Absorbent cotton
Cotton from which all fatty matter has been extracted, so that it
readily takes up fluids.
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Absorbent points
Cones of paper or paper products used to dry or maintain
medicaments during root canal therapy.
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Absorber head
Portion of a rebreathing anesthesia circuit that contains carbon
dioxide absorbent; often referred to as a canister.
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Absorptiometry
Measurement of absorption, of radiation.
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Absorption
Process by which nutrients are absorbed through the lining of the
intestinal tract into capillaries and into the blood stream.
Nutrients must be absorbed to affect the body.
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Absorption band
The range of wavelengths or frequencies in the electromagnetic
spectrum where radiant energy is absorbed by passage through a
gaseous, liquid, or dissolved substance.
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Absorption cell
A small glass chamber with parallel sides, in which absorption
spectra of solutions can be obtained.
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Absorption coefficient
1. The milliliters of a gas at standard temperature and pressure
that will saturate 100 mL of liquid. 2. The amount of light
absorbed in passing through 1 cm of a 1 molar solution of a given
substance, expressed as a constant in Beer-Lambert law. 3. A
measure of the rate of decrease of intensity of an x-ray beam in
its passage through a substance, resulting from a combination of
scattering and conversion to other forms of energy.
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Absorption collapse
Pulmonary collapse due to rapid complete obstruction of a large
bronchus.
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Absorption fever
An elevation of temperature often occurring, without other untoward
symptoms, shortly after childbirth, assumed to result from
absorption of uterine discharges through abrasions of the vaginal
wall.
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Absorption lines
The dark lines in the solar spectrum corresponding to wavelengths
originally emitted by inner layers of the Sun but then absorbed by
various elements present in gaseous form in cooler layers and in
the Earth's atmosphere.
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Absorption spectrum
The spectrum observed after light has passed through, and been
partially absorbed by, a solution or translucent substance.
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Abstinence
Refraining from the use of certain foods, alcoholic beverages, or
illegal drugs, or from sexual activity or other behaviors.
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Abstinence syndrome
A constellation of physiologic changes undergone by people or
animals who have become physically dependent on a drug or chemical
who are abruptly deprived of that substance.
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Abstract
1. A preparation made by evaporating a fluid extract to a powder
and triturating with milk sugar. 2. A condensation or summary of a
scientific or literary article or address.
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Abstract intelligence
The capacity to understand and manage abstract ideas and symbols.
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Abstract thinking
Thinking in terms of concepts and general principles (perceiving a
table and a chair as furniture), as contrasted with concrete
thinking.
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Abstraction
1. Distillation or separation of the volatile constituents of a
substance. 2. Exclusive mental concentration. 3. The making of an
abstract from the crude drug. 4. Malocclusion in which the teeth or
associated structures are lower than their normal occlusal plane.
5. The processes or the results of discernment of formulation of
general concepts from specific examples, and/or ascertainment of a
given aspect of a concept from the whole.
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Abstriction
In fungi, formation of asexual spores by cutting off portions of
the sporophore through the growth of dividing partitions.
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Abterminal
In a direction away from the end and toward the center; denoting
the course of an electrical current in a muscle.
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Abulia
1. Loss or impairment of the ability to perform voluntary actions
or to make decisions. 2. Reduction in speech, movement, thought,
and emotional reaction; a common result of bilateral frontal lobe
disease.
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Abulic
Relating to, or suffering from, abulia.
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Abundance
The average number of types of macromolecules (mRNAs) per cell.
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Abuse
1. Misuse or wrongful use, especially excessive use, of anything.
2. Injurious, harmful, or offensive treatment, as in child abuse or
sexual abuse.
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Abutment
In dentistry, a natural tooth or implanted tooth substitute, used
to support or anchor a fixed or removable prosthesis.
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ABVD
Abbreviation for a chemotherapy regimen of Adriamycin
(doxorubicin), bleomycin, vinblastine, and dacarbazine; used in the
treatment of Hodgkin lymphoma.
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Abvolt
The CGS electromagnetic unit of difference of potential equal to
10−8 V. The potential difference between two points such that 1 erg
of work will be done when 1 abcoulomb of charge moves from point to
point.
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aC
Symbol for arabinosylcytosine.
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Ac
Symbol for actinium; acetyl.
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AC
The abbreviation for the chemotherapy drug combination of an
anthracycline (usually doxorubicin) and cyclophospharnide.
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a-c interval
The interval between the onset of the a wave and that of the c wave
of the jugular pulse.
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Acacia
The dried gummy exudation from Acacia senegal and other species of
Acacia (family Leguminosae), prepared as a mucilage and syrup.
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Acalculia
A form of aphasia characterized by the inability to perform simple
mathematical problems; found with lesions of various areas of the
cerebral hemispheres, and often an early sign of dementia.
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Acampsia
Rarely used term for stiffening or rigidity of a joint for any
reason.
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Acantha
1. A spine or spinous process. 2. The spinous process of a
vertebra.
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Acanthamebiasis
Infection by free-living soil and water amebae of the genus
Acanthamoeba that may result in necrotizing dermal lesions,
fulminating and usually fatal primary amebic meningoencephalitis,
or subacute or chronic granulomatous amebic encephalitis.
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Acanthamoeba
A genus of free-living ameba (family Acanthamoebidae, order
Amoebida) found in and characterized by the presence of
acanthopodia.
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Acanthamoeba medium
Nonnutrient agar plates with an Escherichia coli overlay used to
detect the presence of Acanthamoeba or Naegleria from tissue or
soil samples.
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Acanthella
An intermediate larva stage of Acanthocephala, formed within the
arthropod host; a preinfective, nonencysted stage leading to the
infective cystacanth.
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Acanthesthesia
Paresthesia of a pinprick.
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Acanthia lectularia
Early name for Cimex lectularius.
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Acanthion
The tip of the anterior nasal spine.
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Acantho-
A spinous process; spiny, thorny.
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Acanthocephala
The thorny-headed worms, a phylum (formerly considered a class) of
obligatory parasites without an alimentary canal, characterized by
an anterior introvertible spiny proboscis.
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Acanthocephaliasis
An illness caused by infection with a species of Acanthocephala.
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Acanthocheilonema
A genus of filarial worms parasitic in humans, now considered part
of the genus Mansonella.
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Acanthocyte
An erythrocyte characterized by multiple spiny cytoplasmic
projections, as in acanthocytosis.
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Acanthocytosis
A rare condition in which the most of erythrocytes are
acanthocytes; a regular feature of abetalipoproteinemia; also
sometimes present in severe hepatocellular disease.
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Acanthoid
Spine-shaped.
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Acantholysis
Separation of individual epidermal keratinocytes from their
neighbor, as in conditions such as pemphigus vulgaris and Darier
disease.
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Acanthoma
A tumor formed by proliferation of epithelial squamous cells.
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Acanthopodia
Toothlike pseudopodia observed in some amebae, typically in members
of the genus Acanthamoeba.
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Acanthor
The spindle-shaped embryo, with rostellar hooks and body spines,
formed within the egg shell of Acanthocephala.
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Acanthosis
An increase in the thickness of the stratum spinosum of the
epidermis.
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Acanthosis nigricans
A skin disorder characterized by dark, thick, velvety skin in body
folds and creases.
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Acanthotic
Pertaining to or characteristic of acanthosis.
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Acanthrocyte
Obsolete term for acanthocyte.
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Acanthrocytosis
Obsolete synonym for acanthocytosis.
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Acapnia
Less than the normal level of carbon dioxide in the blood. The
opposite of hypercapnia.
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Acardia
Congenital absence of the heart; a condition sometimes occurring in
one member of monozygotic twins or in one member of conjoined twins
when one partner monopolizes the placental blood supply.
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Acardiac
Without a heart.
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Acardius
A twin without a heart that remains viable by using the placental
circulation of its mate; usually other body parts are also absent.
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Acardius acephalus
An acardiac conceptus in which the head and thoracic organs are
absent; ribs and vertebrae may be present, and upper limbs are
either absent or defective.
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Acardius amorphus
A shapeless product of conception covered by skin and hair.
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Acardius anceps
An acardiac fetus with partly developed head and deformed face,
trunk, and limbs.
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Acariasis
Any disease caused by mites, usually a skin infestation.
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Acaricide
An agent that kills acarines; commonly used to denote chemicals
that kill ticks.
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Acarid
A general term for a member of the family Acaridae or for a mite.
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Acaridae
A family of the order Acarina, a large group of exceptionally small
mites, usually 0.5 mm or smaller, abundant in dried fruits and
meats, grain, meal, and flour; frequently a cause of severe
dermatitis among persons hypersensitized by frequent handling of
infested products.
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Acarina
An order of Arachnida that includes the mites and ticks.
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Acarine
A member of the order Acarina.
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Acarodermatitis
A skin inflammation or eruption produced in response to a mite.
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Acarodermatitis urticarioides
Infestation with the grain itch mite, Pyemotes ventricosus.
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Acaroid
Resembling a mite.
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Acarology
The study of acarine parasites and the diseases they transmit.
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Acarophobia
Morbid fear of small skin parasites, small particles, often
resulting in preoccupation with itching.
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Acarus
A genus of mites of the family Acaridae.
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Acarus balatus
A tropical species of mite that causes a particularly severe type
of scabies-like irritation.
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Acarus hordei
The barley mite, a species that penetrates beneath the skin.
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Acarus rhizoglypticus hyacinthi
A species of mite that develops in spoiled onions; can cause
dermatitis.
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Acarus scabiei
Former term for Sarcoptes scabiei.
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Acatalasia
Absence or deficiency of catalase from blood and tissues, often
manifested by recurrent infection or ulceration of the gingivae
(gums) and related oral structures and caused by mutations in the
catalase gene (CAT) on 11p.
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Acathectic
Rarely used term relating to acathexia.
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Acathexia
Rarely used term for an abnormal release of secretions.
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Acathexis
Older but historically important term for a mental disorder in
which certain objects or ideas fail to arouse an emotional response
in the person.
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Acaudal
Having no tail.
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Acaulose
Acualescent; apparently stemless; the proper stem; bearing the
leaves and flowers; being very short or subterranean.
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ACC
Abbreviation for anodal closure contraction.
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Accelerans
1. Accelerating. 2. Obsolete term for an accelerator (sympathetic)
nerve to the heart.
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Accelerated conduction
Any pathologically increased speed of conduction; usually occurs
between the atrium and ventricles as in the Wolff-Parkinson-White
and Lown-Ganong-Levine syndromes; such accelerated pathways provide
the bases for particular forms of reentry tachycardia.
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Accelerated eruption
A dental eruption pattern that is chronologically advanced in
comparison with the average pattern of dental eruption.
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Accelerated hypertension
Hypertension advancing rapidly with increasing blood pressure and
associated with acute and rapidly worsening signs and symptoms.
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Accelerated phase of leukemia
Refers to chronic myelogenous leukemia that is progressing. The
number of immature, abnormal white blood cells in the bone marrow
and blood is higher than in the chronic phase, but not as high as
in the blast phase.
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Accelerated reaction
A response occurring in a shorter time than expected.
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Accelerated rejection
A transplant rejection manifested in less than 3 days.
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Acceleration
1. The act of accelerating. 2. The rate of increase in velocity per
unit of time; commonly expressed in g units; also expressed in
centimeters or feet per second squared. 3. The rate of increasing
deviation from a rectilinear course.
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Accelerator
1. Anything that increases rapidity of action or function. 2. In
physiology, a nerve, muscle, or substance that quickens movement or
response. 3. A catalytic agent used to hasten a chemical reaction.
4. In nuclear physics, a device that accelerates charged particles
(protons) to high speed to produce nuclear reactions in a target,
for the study of subatomic structure, for the production of
radionuclides, or for radiation therapy.
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Accelerator fibers
Postganglionic sympathetic nerve fibers originating in the
superior, middle, and inferior cervical ganglia of the sympathetic
trunk, conveying nervous impulses to the heart that increase the
rapidity and force of the cardiac pulsations.
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Accelerator globulin
Globulin in serum that promotes the conversion of prothrombin to
thrombin in the presence of thromboplastin and ionized calcium.
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Accelerator nerves
Certain of the cardiopulmonary splanchnic nerves establishing the
sympathetic innervation of the heart.
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Accelerin
Obsolete term for what was once considered an intermediary product
of coagulation but is no longer thought to exist.
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Accelerometer
An instrument for measuring the rate of change of velocity per unit
of time.
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Accentuator
A substance such as aniline, the presence of which allows a
combination between a tissue or histologic element and a stain that
might otherwise be impossible.
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Acceptor
1. A compound that will take up a chemical group (an amine, methyl,
or carbamoyl group) from another compound (the donor); under the
action of alanine transaminase, l-glutamate is an amine donor
whereas pyruvate is an amine acceptor. 2. A receptor that binds a
hormone. 3. A drug-binding receptor that has no identified
endogenase ligand.
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Acceptor site
The location of ribosomal binding for the aminoacyl-tRNA during
protein synthesis.
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Acces pernicieux
A series of severe attacks of falciparum malaria, sometimes
occurring in apparently mild cases; roughly classified as cerebral
and algid.
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ACCESS
Access Energy Transformation. "Energy technique" that supposedly
works with the "creative force" to free it and connect it to the
"Light" ("us.") Allegedly, Novian, a "Being of Light," channeled
the method to Gary Douglas through the Russian monk Grigori
Efimovich Rasputin (1872-1916). ACCESS theory posits: (a) 32
"Bars," points on the head that are a means of allowing the flow of
bodily "energies"; (b) a "Soul"; (c) "Implants," electrical devices
(e.g., a "False Immune System") inserted in another lifetime and
attached "electrically" to the Soul's "energy"; and (d) "Entities,"
disembodied beings or "thought forms." Purportedly, ACCESS removes
"energetic blocks" at cellular and "etheric" levels and enables one
to reclaim "awareness as an eternal being."
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Accessory
Anatomy denoting structures (muscles, arteries, nerves, glands, and
others) that are auxiliary (normally present) or supernumerary
(anomalous) to another more typical or larger structure of the same
type.
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Accessory adrenal
An island of adrenal cortical tissue separate from the adrenal
gland, usually found in the retroperitoneal tissues, kidney, or
genital organs.
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Accessory auricles
Small, fleshy nodules or folds, sometimes with supporting
cartilage, occasionally found along the margins of the embryonic
pharyngeal grooves.
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Accessory branch of middle meningeal artery
A branch of either the middle meningeal or maxillary artery in the
infratemporal fossa and passing superiorly through the foramen
ovale to supply the trigeminal ganglion, dura mater, and inner
table of bone.
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Accessory breast
A milk-secreting gland located elsewhere than at the normal place
on the front of the chest and existing in addition to the two usual
mammae.
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Accessory canal
In the tooth, a channel leading from the root pulp laterally
through the dentin to the periodontal tissue; may be found anywhere
in the tooth root but is more common in the apical third of the
root.
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Accessory cartilage
A sesamoid cartilage.
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Accessory cephalic vein
A variable vein that passes along the radial border of the forearm
to join the cephalic vein near the elbow.
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Accessory chromosome
A supernumerary chromosome that is not an exact replica of any of
the chromosomes in the normal cellular complement.
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Accessory cuneate nucleus
A cell group lateral to the cuneate nucleus that receives
posterior-root fibers corresponding to the proprioceptive
innervation of the arm and hand; it projects to the cerebellum by
way of the cuneocerebellar tract and can be considered the
upper-extremity equivalent of the thoracic nucleus.
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Accessory flocculus
An occasional small lobule of the cerebellum adjacent to the
flocculus.
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Accessory gland
A small mass of glandular structure, detached from but lying near
another and larger gland, to which it is similar in structure and
probably in function.
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Accessory hemiazygos vein
Vein formed by the union of the fourth to seventh left posterior
intercostal veins, it passes along the side of the bodies of the
fifth, sixth, and seventh thoracic vertebrae, then crosses the
midline posterior to the aorta, esophagus, and thoracic duct, and
empties into the azygos vein, sometimes in common with the
hemiazygos vein.
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Accessory lacrimal glands
Small, compound, branched, tubular glands located sometimes in the
middle part of the lid (Wolfring glands, 1872, or Ciaccio glands,
1874) or along the superior and inferior fornices of the
conjunctival sac (Krause glands, 1854). These accessory glands are
ectopic portions of the lacrimal gland tissue; all produce the same
kind of tears, secreting onto the conjunctival surface.
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Accessory lymph nodes
The nodes of the lateral deep cervical group that are located along
the accessory nerve; their efferent vessels pass to the
supraclavicular lymph nodes.
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Accessory molecules
Surface receptors on immune cells, which participate in cell-cell
interactions and modulate the immunologic outcome.
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Accessory nasal cartilages
Variable small plates of cartilage located in the interval between
the greater alar and lateral nasal cartilages.
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Accessory nerve
Nerve that arises by two sets of roots: the presumed cranial,
emerging from the side of the medulla, and the presumed spinal,
emerging from the ventrolateral part of the first five cervical
segments of the spinal cord; these roots unite to form the
accessory nerve trunk, which divides into two branches, internal
and external; the internal branch, carrying fibers of the cranial
root, unites with the vagus in the jugular foramen and supplies the
muscles of the pharynx, larynx, and soft palate; the external
branch continues independently through the jugular foramen to
supply the sternocleidomastoid and trapezius muscles.
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Accessory nerve trunk
Part of the accessory nerve formed within the cranial cavity by the
union of the traditional cranial and spinal roots, which then
divides within the jugular foramen into internal and external
branches, the former uniting with the vagus, the latter exiting the
foramen as an independent branch that is commonly considered to be
the accessory nerve.
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Accessory nipple
A supernumerary nipple occurring on the mammary crest.
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Accessory nuclei of optic tract
Small groups of neuron cell bodies located along the trajectory of
optic fibers in the mesencephalon.
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Accessory obturator artery
Term applied to the anastomosis of the pubic branch of the inferior
epigastric artery with the pubic branch of the obturator artery
when it contributes a significant supply through the obturator
canal in the presence of (reduced) normal obturator arising from
the internal iliac artery.
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Accessory obturator nerve
L3-L4 nerve fibers usually conveyed by the obturator nerve that
comprise a separate nerve running independently to the pectineus
(muscle) and hip joint.
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Accessory pancreas
A detached portion of pancreatic tissue, usually the uncinate
process (part of head of the pancreas), and hence most often found
in the vicinity of the head, but which may occur within the gut
wall (stomach or duodenum).
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Accessory pancreatic duct
The excretory duct of the head of the pancreas formed from the
proximal part of the duct of the embryonic dorsal pancreatic bud,
that opens independently into the duodenum at the lesser duodenal
papilla.
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Accessory parathyroid gland
An additional (or detached portion of a) parathyroid gland,
resulting in at least five but usually many more glandular units.
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Accessory parotid gland
An occasional islet of parotid tissue separate from the mass of the
gland, lying anteriorly just above the commencement of the parotid
duct.
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Accessory phrenic nerves
Accessory nerve strands that arise from the fifth cervical nerve,
often as branches of the nerve to the subclavius, passing downward
to join the phrenic nerve.
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Accessory placenta
An extra placenta separate from the main placenta. Also called a
succenturiate or supernumerary placenta.
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Accessory process of lumbar vertebra
A small apophysis at the posterior part of the base of the
transverse process of each of the lumbar vertebrae.
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Accessory root of tooth
An anomalous additional tooth root.
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Accessory saphenous vein
An occasional vein running in the thigh parallel to the great
saphenous vein which it joins just before the latter empties into
the femoral vein.
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Accessory sign
A finding frequently but not consistently present in a disease.
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Accessory spleen
One of the small globular masses of splenic tissue occasionally
found in the region of the spleen, in one of the peritoneal folds
or elsewhere.
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Accessory structures
Parts accessory to the main organ or structure.
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Accessory suprarenal glands
Isolated, often minute, masses of suprarenal tissue sometimes found
near the main glands or in the broad ligament or the epididymis.
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Accessory symptom
A symptom that usually but not always accompanies a certain
disease, as distinguished from a pathognomonic symptom.
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Accessory thymic tissue
An isolated mass of tissue that arises from the developing thymus
and enters the neck, often close to an inferior parathyroid gland.
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Accessory thyroid gland
An isolated mass, or one of several such masses, of thyroid tissue,
sometimes present in the side of the neck, or ranging in position
from just superior to the hyoid bone (suprahyoid accessory thyroid
gland) to the arch of the aorta inferiorly.
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Accessory thyroid tissue
An isolated mass of tissue that arises from the developing thyroid
gland and appears in the tongue or thymus gland.
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Accessory tragus
Small nodules present at birth, anterior to the tragus, derived
from first branchial arch remnants and often containing central
cartilage.
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Accessory vertebral vein
A vein that accompanies the vertebral vein but which passes through
the foramen of the transverse process of the seventh cervical
vertebra and opens independently into the brachiocephalic vein.
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Accessory visual structures
The eyelids, with lashes and eyebrows, lacrimal apparatus,
conjunctival sac, and extrinsic muscles of the eyeball.
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Accident
An unplanned or unintended but sometimes predictable event leading
to injury, in traffic, industry, or a domestic setting, or such an
event developing in the course of a disease.
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Accidental host
Host that harbors an organism that usually does not infect it.
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Accidental hypothermia
An abnormally low body temperature. It is a dangerous condition
caused when the body loses more heat than it can produce.
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Accidental murmur
An evanescent cardiac murmur resulting from causes other than
valvular lesion.
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Accidental myiasis
Gastrointestinal myiasis from ingestion of contaminated food.
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Accidental symptom
Any morbid phenomenon coincidentally occurring in the course of a
disease, but having no relation with it.
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Accident-prone
1. Experiencing a greater number of accidents than would be
expected of the average person in similar circumstances. 2. Having
personality characteristics predisposing one to accidents.
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Acclimating fever
Elevated temperature with malaise that affects persons working in a
very hot environment.
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Acclimatization
Physiologic adjustment of a person to a different climate,
especially to a change in environmental temperature or geographic
elevation.
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Accommodation
1. The act or state of adjustment or adaptation. 2. In sensorimotor
theory, the alteration of schemata or cognitive expectations to
conform with experience.
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Accommodation of eye
The increase in thickness and convexity of the eye's lens in
response to ciliary muscle contraction to focus the image of an
external object on the retina.
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Accommodation of nerve
The property of a nerve by which it adjusts to a slowly increasing
level of stimulus, so that its threshold of excitation is greater
than it would be were the stimulus level to have risen more
rapidly.
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Accommodation phosphene
A phosphene occurring during accommodation, caused by sudden
relaxation of the ciliary muscle.
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Accommodation reflex
Increased convexity of the lens, resulting from contraction of the
ciliary muscle and relaxation of the suspensory ligament, to
maintain a distinct retinal image.
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Accommodative
Relating to accommodation.
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Accommodative asthenopia
Asthenopia resulting from errors of refraction and excessive
contraction of the ciliary muscle.
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Accommodative convergence
The meter angle of convergence expressed in diopters; equal to the
product of the meter angles of convergence multiplied by the
interpupillary distance measured in centimeters.
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Accommodative insufficiency
A lack of appropriate accommodation for near focus.
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Accommodative strabismus
Strabismus in which the severity of deviation varies with
accommodation.
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Accomplice
A bacterium that accompanies the main infecting agent in a mixed
infection and that influences the virulence of the main organism.
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Accouchement
Childbirth, particularly parturition.
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Accouchement force
Forced, artificially hastened fetal delivery, most commonly by
means of version or the use of forceps; originally applied to rapid
dilation of the cervix with the hands, with version and forcible
extraction of the fetus.
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Accoucheur
French for a male obstetrician.
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Accoucheur hand
A position of the hand in which the fingers, touching one another,
are flexed at the metacarpophalangeal joints and extended at the
phalangeal joints, with the thumb flexed and adducted into the
palm; the resulting hand posture resembles that of a physician's
during a vaginal examination.
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Accoucheuse
French for a female obstetrician or midwife.
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Accrementition
Reproduction by budding or germination.
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Accrete
Accrescent; growing larger after flowering.
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Accretio cordis
Adhesion of the pericardium to adjacent extracardiac structures.
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Accretion
1. Increase by addition to the periphery of material of the same
nature as that already present; the manner of growth of crystals.
2. In dentistry, foreign material (usually plaque or calculus)
collecting on the surface of a tooth or in a cavity. 3. A growing
together.
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Accretion lines
Lines seen in microscopic sections of the enamel, marking
successive layers of added material.
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Accretionary growth
Growth by an increase of intercellular material.
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Accrochage
Intermittent synchronization of two different rhythms of the heart
with one influencing the behavior of the other when neither is
dominant; seen in cases of atrioventricular dissociation when an
atrial beat falls shortly after a ventricular beat, the latter
causing the atrial beat to occur sooner than expected.
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Accumulation analysis
A technique in which an intermediate of a metabolic pathway
accumulates because of selective inhibition of a particular step in
that pathway or in a mutant that is deficient in a certain step.
The intermediate is then isolated, analyzed, and identified.
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Accumulation disease
A disease characterized by abnormal accumulation of a metabolic
product in certain cells and tissues; examples include the
mucopolysaccharidoses and lipoidoses.
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Accuracy
The degree to which a measurement, or an estimate based on
measurements, represents the true value of the attribute being
measured.
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ACD
Abbreviation for acid-citrate-dextrose.
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ACE
Abbreviation for angiotensin converting enzyme. An enzyme that is
related to high blood pressure.
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ACE inhibitor
A drug that blocks the formation of a natural body chemical, thus
relaxing blood vessels and decreasing water and salt retention.
It's used to lower blood pressure or manage heart failure.
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Acedia
Obsolete term for a mental syndrome, the chief features of which
are listlessness, carelessness, apathy, and melancholia.
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ACEI
Abbreviation for angiotensin-converting enzyme inhibitors.
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Acellular
1. Devoid of cells. 2. A term applied to unicellular organisms that
do not become multicellular and are complete within a single cell
unit; frequently applied to protozoans to emphasize their complete
organization within a single cell.
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Acellular cement
A type I collagen hard tissue that has neither cementocytes nor
lacunae and covers the coronal half to two thirds of the root of
the tooth; usually covers the entire root in incisors and canines.
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Acelom
Absence of a true celom or body cavity lined with mesothelium;
typically found in Platyhelminthes (flatworms), which have a
syncytial mass of parenchymal cells instead of a true body cavity.
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Acelomate
Not having a celom or body cavity.
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Acentric
A chromosome fragment lacking a centromere (the "waist" of the
chromosome essential for the division and the retention of the
chromosome in the cell.)
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Acentric chromosome
A fragment of a chromosome lacking a centromere and unable to
attach to the mitotic spindle; therefore unable to take part in the
division of a nucleus and randomly distributed in daughter cells.
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Acephalgic migraine
A classic migraine episode in which the teichopsia is not followed
by a headache.
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Acephaline
Denoting members of the protozoan suborder Acephalina (order
Eugregarinida), characterized by simple noncompartmentalized
bodies, which parasitize invertebrates.
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Acephalocardia
Absence of head and heart as seen in a parasitic twin.
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Acephalocheiria
Congenital absence of head and hands.
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Acephalocyst
A serile hydatid cyst, so called because it fails to develop
scoleces (tapeworm heads).
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Acephalogasteria
Congenital absence of head, thorax, and abdomen as seen in a
parasitic twin with pelvis and lower limbs only.
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Acephalopodia
Congenital absence of head and feet.
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Acephalorrhachia
Congenital absence of head and vertebral column.
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Acephalothoracia
Congenital absence of head and thorax.
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Acephalous
Headless.
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Acephalus
A headless fetus.
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Acephalus acormus
Condition in which a head without a body is attached to the
placenta by an umbilical cord.
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Acephalus dibrachius
A fetus lacking a head but having two recognizably developed upper
limbs.
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Acephalus dipus
A fetus lacking a head but having two recognizably developed lower
limbs.
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Acephalus monobrachius
A fetus lacking a head and showing only one recognizable upper
limb.
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Acephalus monopus
A fetus lacking a head and with fusion of the lower limbs so
extreme that only a single foot is recognizable.
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Acephalus sympus
A fetus lacking a head and showing fusion of the lower limbs.
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Acephaly
Congenital absence of the head.
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Acerola
Fruit of a bushy tree (Malpighia glabra) that grows in Central and
South America and Puerto Rico. The berry is the richest known
source of vitamin C (ascorbic acid).
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Acestoma
Exuberant granulations that form a cicatrix.
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Acet-
Combining forms denoting the two-carbon fragment of acetic acid.
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Acetabula
Plural of acetabulum.
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Acetabular
Relating to the acetabulum.
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Acetabular branch
An arterial branch that supplies the acetabulum; two arteries, the
obturator and the medial femoral circumflex, have such branches.
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Acetabular fossa
A depressed area in the floor of the acetabulum superior to the
acetabular notch and bounded on all other sides by the lunate
(articular) surface.
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Acetabular labrum
A fibrocartilaginous rim attached to the margin of the acetabulum
of the hip bone.
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Acetabular margin
The rim of bone around the acetabulum to which is attached the
labrum acetabulare.
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Acetabular notch
A gap in the inferior the margin of the acetabulum, bridged by the
transverse acetabular ligament, giving passage to the acetabular
branches of the obturator artery and vein.
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Acetabulectomy
Excision of the acetabulum.
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Acetabuloplasty
Any operation aimed at restoring the acetabulum to as near a normal
state as possible.
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Acetabulum
The cup-shaped socket of the hip joint.
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Acetal
Product of the addition of 2 mol of alcohol to 1 mol of an
aldehyde; in mixed acetals (glycosides), two different alcohols are
bound to the original aldehyde group.
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Acetaldehyde
An intermediate in yeast fermentation of carbohydrate and in
alcohol metabolism. It is a central agent for the toxic effects of
ethanol.
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Acetamide
Used in biomedical research.
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Acetaminophen
The generic name for a common nonprescription medication useful in
the treatment of mild pain or fever. This is called paracetamol in
the United Kingdom.
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Acetate
A salt or ester of acetic acid.
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Acetate kinase
A phosphotransferase forming acetyl phosphate and ADP from ATP and
acetate.
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Acetazolamide
The heterocyclic sulfonamide
5-acetylamido-1,3,4-thiadiazole-2-sulfonamide, which inhibits the
action of carbonic anhydrase in the kidney, increasing the urinary
excretion of sodium, potassium, and bicarbonate, reducing excretion
of ammonium, raising the pH of the urine, and lowering the pH of
the blood.
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Acetic
1. Denoting the presence of the two-carbon fragment of acetic acid.
2. Relating to vinegar; sour.
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Acetic acid
A product of the oxidation of ethanol and of the destructive
distillation of wood; used locally as a counterirritant and
occasionally internally, and also as a reagent; contained in
vinegars.
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Acetic fermentation
Fermentation, as of wine or beer, whereby the alcohol is oxidized
to acetic acid (vinegar).
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Acetic solution
A vinegar. Acetic solution is used in the treatment of superficial
bacterial infections of the external auditory canal.
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Aceticoceptor
A side chain of molecules with a special affinity for the acetic
acid radical.
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Acetify
To cause acetic fermentation; to make vinegar or become vinegar.
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Acetimeter
An apparatus for determining the content of acetic acid in vinegar
or other fluids.
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Acetoacetate
A salt or ion of acetoacetic acid. A ketone body formed in
ketogenesis.
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Acetoacetate decarboxylase
A carboxy-lyase cleaving CO2 from acetoacetate to form acetone.
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Acetoacetic acid
One of the ketone bodies, formed in excess and appearing in the
urine in starvation or diabetes.
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Acetoacetyl-CoA
Intermediate in the oxidation of fatty acids and in the formation
of ketone bodies; also formed from two molecules of acetyl-CoA and
in the degradation of ketogenic amino acids; major role is
condensation with acetyl-CoA to form
β-hydroxy-β-methylglutaryl-CoA.
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Acetoacetyl-CoA reductase
An oxidoreductase catalyzing the interconversion of a 3-oxoacyl-CoA
and NADPH to the corresponding d-3-hydroxyacyl-CoA and NADP+.
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Acetoin
A condensation product of two molecules of acetaldehyde.
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Acetol
Common term for 1-hydroxy-2-propanone or hydroxyacetone.
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Acetolysis
Decomposition of an organic compound with the addition of the
elements of acetic acid at the point of decomposition; analogous to
hydrolysis and phosphorolysis.
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Acetone
A colorless, volatile, flammable liquid; extremely small amounts
are found in normal urine, but larger quantities occur in the urine
and blood of people with diabetes, sometimes imparting an ethereal
odor to the urine and breath. Acetone is one of the ketone bodies,
and is used as a solvent in many pharmaceutical and commercial
preparations.
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Acetone fixative
Acetone used at low temperatures to fix enzymes, particularly
phosphatases; it removes fat and glycogen.
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Acetone test
Test for the presence of ketonuria; a sample of the suspected urine
is shaken up with a few drops of sodium nitroprusside and a strong
solution of ammonia water is then gently poured over the mixture;
if acetone is present, a magenta ring forms at the line of contact.
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Acetonemia
The presence of acetone or acetone bodies in relatively large
amounts in the blood, manifested at first by excitability, and
later by a progressive depression.
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Acetonemic
Relating to or caused by acetonemia.
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Acetonitrile
A colorless fluid of aromatic odor, soluble in water and alcohol.
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Acetonuria
Excretion in the urine of large amounts of acetone, an indication
of incomplete oxidation of large amounts of lipids; commonly occurs
in diabetic acidosis.
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Acetoorcein stain
A stain used for chromosomes in air-dried or squashed cytologic
material.
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Acetous
Relating to vinegar; sour-tasting.
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Acetowhitening
Blanching of skin or mucous membranes, after application of 3-5%
acetic acid solution, a sign of increased cellular protein and
increased nuclear density; used particularly on genital skin and
mucous membranes, including the uterine cervix, to identify zones
of squamous cell change for biopsy and condyloma acuminatum for
treatment.
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Aceturate
USAN-approved contraction for N-acetylglycinate.
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Acetyl
An acetic acid molecule from which the hydroxyl group has been
removed.
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Acetyl chloride
A colorless liquid used as a reagent; also corrosive, causing
severe burns because of hydrolysis to HCl.
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Acetyl CoA, Acetyl Coenzyme A
Condensation product of coenzyme A and acetic acid.
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Acetyl phosphate
A "high-energy" phosphate that acts as an acetyl donor in the
metabolism of various bacteria.
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Acetyl value
The milligrams of potassium hydroxide required to neutralize the
acetic acid produced by the hydrolysis of 1 g of acetylated fat; a
measure of the hydroxy acids present in glycerides.
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Acetyladenylate
Mixed anhydride between the carboxyl group of acetic acid and the
phosphoric residue of adenosine 5′-monophosphate.
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Acetylase
Any enzyme catalyzing acetylation or deacetylation, as in the
formation of N-acetylglutamate from glutamate plus acetyl-CoA, or
the reverse.
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Acetylation
The addition of an acetyl group (-COCH3) group to a molecule.
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Acetylcholine
1. The ester of choline and acetic acid that is widespread in the
body and functions as a neurotransmitter at synapses and
neuromuscular junctions. 2. One of the chemicals that transmits
impulses between nerves and between nerves and muscle cells.
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Acetylcholinergic
Pertaining to the action of acetylcholine or to neural or metabolic
pathways in which it functions as a transmitter.
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Acetylcholinesterase
Enzyme that catalyzes the degradation of acetylcholine, thus
inactivating it. A neurotransmitter enzyme that hydrolyzes
acetylcholine to acetate and choline.
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Acetyl-CoA
An enzyme involved in the synthesis of certain carbohydrate
moieties on proteins; deficiency of this enzyme leads to
mucopolysaccharidosis type III C.
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Acetyl-CoA acyltransferase
An enzyme catalyzing the thioclastic cleavage by coenzyme A of
β-ketoacyl-CoA, forming an acyl-CoA with a carbon chain shorter by
two atoms, the missing two atoms appearing as acetyl-CoA.
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Acetyl-CoA carboxylase
A ligase that catalyzes the reaction of acetyl-CoA, CO2, H2O, and
ATP, with covalently bound biotin to form malonyl-CoA, ADP, and Pi
(or the reverse decarboxylase); N-carboxybiotin is an intermediate.
A crucial enzyme in fatty acid synthesis.
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Acetyl-CoA hydrolase
A hydrolase that produces acetate and coenzyme A from acetyl-CoA.
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Acetylcysteine
A drug usually used to reduce the thickness of mucus and ease its
removal. It is also used to reverse the toxicity of high doses of
acetaminophen. Also called N-acetyl-L-cysteine.
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Acetylornithine deacetylase
An enzyme catalyzing the hydrolysis of N2-acetyl-l-ornithine to
l-ornithine and acetate.
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Acetylsalicylic acid
An odorless, white, slightly bitter drug used to reduce pain,
fever, inflammation, and sometimes to prevent blood clotting. Also
called aspirin.
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Acetyltransferase
Any enzyme transferring acetyl groups from one compound to another.
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AcG
Abbreviation for accelerator globulin.
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ACH
Abbreviation for acetylcholine.
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Achalasia
A relatively rare disorder of the smooth muscle of the esophagus,
which makes it difficult for food and liquid to pass into the
stomach from the esophagus.
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Achard syndrome
Arachnodactyly with small receding mandible, broad skull, and joint
laxity limited to the hands and feet; genetics unclear.
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Achard-Thiers syndrome
Obsolete term for a form of a virilizing disorder of adrenocortical
origin in women, characterized by masculinization and menstrual
disorders in association with manifestations of diabetes mellitus,
such as glucosuria.
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Ache
A dull, poorly localized pain, usually of less than severe
intensity.
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Acheilia
Congenital absence of the lips.
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Acheilous
Characterized by or relating to acheilia.
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Acheiria
1. Congenital absence of one or both hands. 2. Anesthesia in one or
both hands with loss of the sense of possession of the hand or
hands. 3. A sensibility disorder in which the patient is unable to
identify which side of the body has received a stimulus.
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Acheiropody
Congenital absence of the hands and feet; autosomal recessive
inheritance.
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Acheirous
Characterized by or relating to acheiria.
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Achenbach syndrome
Hematoma of the finger pad with accompanying edema; of unknown
cause in the absence of disturbances in blood coagulation
mechanisms.
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Achene
Small, hard one-seeded fruit.
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Achievement age
Age derived from a given level of achievement on a standardized
test, which can be compared with a person's chronologic age.
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Achievement motive
An acquired, chronic need to succeed in the face of recognizable
obstacles; its strength is usually diagnosed from recurring themes
in stories told by the patient while taking a thematic apperception
test or from other assessment instruments used by clinical
psychologists.
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Achievement quotient
A ratio, percentile rating, or related quotient denoting the amount
a child has learned in relation to peers of his or her age or level
of education.
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Achievement test
A standardized test used to measure acquired learning, in a
specific subject area such as reading or arithmetic, in contrast to
an intelligence test, which measures potential ability or learning
capacity.
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Achilles
Mythic Greek warrior, vulnerable to wounding only in his heel.
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Achilles reflex
A contraction of the calf muscles when the tendo calcaneus is
sharply struck.
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Achilles tendinitis
An inflammation and/or degeneration of the Achilles tendon.
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Achilles tendon
The tendon at the back of the leg directly above the heel.
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Achillobursitis
Inflammation of a bursa in proximity to the tendo calcaneus.
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Achillotenotomy
Cutting of the Achilles tendon.
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Achiral
Not chiral; denoting an absence of chirality.
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Achlorhydria
A lack of hydrochloric acid in the digestive juices in the stomach.
Hydrochloric acid helps digest food.
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Achlorhydric anemia
A form of chronic hypochromic microcytic anemia associated with
achlorhydria or achylia gastrica; observed most frequently in women
in the third to fifth decades.
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Achlorophyllous
Without chlorophyll, as in fungi.
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Acholeplasma
Genus of bacteria that has characteristics identical to those of
the genus Mycoplasma, with the exception that the acholeplasmas do
not require sterol for growth.
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Acholeplasma axanthum
A species originally found in a murine leukemia cell line; ecology
bovine, porcine, botanic.
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Acholeplasma laidlawii
A species that occurs as a saprophyte in sewage, manure, humus, and
soil. One of two species isolated from humans.
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Acholeplasma ocular
One of only two species isolated from humans.
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Acholeplasma oculi
Isolated from eyes of caprines affected by keratoconjunctivitis.
Also isolated from goat udders and genital lesions, and from calves
affected with bovine infectious keratoconjunctivitis.
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Acholia
Suppressed or absent secretion of bile.
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Acholic
Without bile, as in acholic (pale) stools.
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Acholuria
Absence of bile pigments from the urine in certain cases of
jaundice.
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Acholuric jaundice
Jaundice with excessive amounts of unconjugated bilirubin in the
plasma and without bile pigments in the urine.
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Achondrogenesis
A defect in the development of bone and cartilage. It is thought to
be inherited.
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Achondrogenesis type IA
Achondrogenesis with hypervascular cartilage and hypercellular
bone; uncertain inheritance pattern.
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Achondroplasia
A genetic disorder in which bone and cartilage do not grow
normally. It is the most common cause of dwarfism.
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Achondroplastic
Relating to or characterized by achondroplasia.
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Achondroplastic dwarfism
A genetic disorder that causes dwarfism (short stature.) It is a
disorder in which bone and cartilage do not grow normally.
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Achordate
Referring to animal forms below the level of Chordata that do not
develop a notochord or chorda.
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Achoresis
Permanent contraction of a hollow viscus, such as the stomach or
bladder, whereby its capacity is reduced.
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Achorion
Former name for dermatophytes now placed in the genus Trichophyton
or Microsporum.
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Achrestic anemia
A form of chronic progressive macrocytic anemia, potentially fatal,
in which the changes in bone marrow and circulating blood closely
resemble those of pernicious anemia, but in which there is at best
only transient response to therapy with vitamin B12.
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Achroacyte
A colorless cell.
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Achromasia
Pallor associated with hippocratic facies, emaciation, and
weakness, often heralding a moribund state.
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Achromat
A person exhibiting achromatopsia.
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Achromatic
1. Colorless. 2. Not staining readily. 3. Refracting light without
chromatic aberration.
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Achromatic apparatus
The nonstaining asters and spindle fibers in a dividing cell.
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Achromatic lens
Compound lens made of two or more lenses having different indices
of refraction, so correlated as to minimize chromatic aberration.
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Achromatic objective
An objective that is corrected for two colors chromatically, and
one color spherically.
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Achromatin
The weakly staining components of the nucleus, such as the nuclear
sap and euchromatin.
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Achromatinic
Relating to or containing achromatin.
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Achromatism
1. The quality of being achromatic. 2. The annulment of chromatic
aberration by combining glasses of different refractive indexes and
different dispersion.
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Achromatolysis
Dissolution of the achromatin of a cell or of its nucleus.
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Achromatophil
1. Not being colored by the histologic or bacteriologic stains. 2.
A cell or tissue that cannot be stained in the usual way.
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Achromatophilia
A condition of being refractory to staining processes.
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Achromatopsia
The complete form of achromatopsia, characterized by severe
deficiency of color perception, associated with nystagmus,
photophobia, reduced visual acuity, and "day blindness;" is of
autosomal recessive inheritance.
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Achromatous
Colorless.
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Achromaturia
The passage of colorless or very pale urine.
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Achromia
1. Hypopigmentation; absence or loss of natural pigmentation of the
skin and iris; may be congenital or acquired. 2. Lack of capacity
to accept stains in cells or tissue.
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Achromia parasitica
A phase of lessening or absence of pigmentation in cutaneous
lesions, caused by the fungus Malassezia furfur.
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Achromic
Colorless.
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Achromobacter
A gram-negative bacterial genus of uncertain clinical significance,
closely related to members of the Alcaligenes and Ochrobactrum
species.
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Achromocyte
A hypochromic, crescentic erythrocyte, probably resulting from
artifactual rupture with loss of hemoglobin.
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Achromotrichia
Absence or loss of pigment in the hair.
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Achrondrogenesis type IB
Achondrogenesis with severely disorganized intracartilaginous
ossification; autosomal recessive inheritance, caused by mutation
in the diastrophic dysplasia sulfate transporter gene (DTDST) on
chromosome 5q.
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Achrondrogenesis type II
Achondrogenesis with autosomal dominant inheritance, caused by
mutation in the collagen type II gene (COL2A1) on chromosome 12q.
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Achroodextrin
Dextrin of low molecular weight, formed from starch in a stage of
the digestion of the latter by amylase; it produces no color
reaction with iodine.
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Achylia
1. Absence of gastric juice or other digestive secretions. 2.
Absence of chyle.
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Achylia gastrica
Diminished or abolished secretion of gastric juice associated with
atrophy of the mucous membrane of the stomach.
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Achylia pancreatica
Deficiency or absence of pancreatic secretion, usually resulting in
fatty stools, emaciation, and impaired nutrition.
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Achylous
1. Lacking in gastric juice or other digestive secretions. 2.
Having no chyle.
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Acicular
Needle shaped or needle pointed; applied particularly to leaves and
crystals.
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Acid
1. A compound yielding a hydrogen ion in a polar solvent (in
water); acids form salts by replacing all or part of the ionizable
hydrogen with an electropositive element or radical. 2.
Colloquially, any chemical compound that has a sour taste (given by
the hydrogen ion). 3. Sour; sharp to the taste. 4. Relating to
acid; giving an acid reaction.
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Acid agglutination
The clumping together of certain microorganisms at high hydrogen
ion concentration.
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Acid alcohol
Ethyl alcohol (70%) containing 1% hydrochloric acid.
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Acid dextran
The product of acid and heat treatment of dextran.
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Acid dextrin
The product of acid and heat treatment of dextrin.
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Acid dyspepsia
Dyspepsia associated with excess gastric acidity.
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Acid etch cemented splint
A splint of heavy wire that is cemented to the labial surfaces of
teeth with any of the acid etch cement techniques; used to
stabilize traumatically displaced or periodontally diseased teeth.
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Acid fuchsin
A mixture of the sodium salts, bi- and trisulfonic acids of
rosanilin and pararosanilin; used as an indicator dye and for
staining of cytoplasm and collagen.
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Acid gland
One of the gastric glands that secretes the hydrochloric acid of
the gastric juice.
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Acid indigestion
Indigestion resulting from hyperchlorhydria; often used
colloquially as a synonym for pyrosis.
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Acid intoxication
Poisoning by acid products (β-oxybutyric acid, diacetic acid, or
acetone) formed as a result of faulty metabolism (uncontrolled
diabetes mellitus) or by acids introduced from without; marked by
epigastric pain, headache, loss of appetite, constipation,
restlessness, and an odor of acetone on the breath, followed by air
hunger, coma, and collapse.
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Acid mantle
The protective coating on the skin that is inhospitable to
bacteria.
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Acid oxide
An acid anhydride; an oxide of an electronegative element or
radical; it can combine with water to form an acid.
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Acid phosphatase
A phosphatase with an optimum pH of less than 7 (for several
isozymes, it is 5.4), notably present in the prostate gland;
demonstrable in lysosomes with Gomori nonspecific acid phosphatase
stain; it hydrolyzes many orthophosphoric monoesters.
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Acid phosphatase test for semen
A screening test for semen that gauges acid phosphatase content;
because seminal fluid contains high concentrations of acid
phosphatase, whereas other body fluids and extraneous foreign
materials have very low concentrations, high values of acid
phosphatase on vaginal aspirate or lavage, or on wash fluid from
stains, render positive identification of semen, even if the male
is aspermic.
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Acid radical
A radical formed from an acid by loss of one or more hydrogen ions;
SO4−, NO3−.
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Acid reaction
1. Any test by which an acid reaction is recognized, such as the
change of blue litmus paper to red. 2. An excess of hydrogen ions
over hydroxide ions in aqueous solution indicated by a pH value
less than 7 (at 22°C).
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Acid reflux test
A test to detect gastroesophageal reflux by monitoring esophageal
pH either basally or after acid is instilled into the stomach, by
means of an electrode in the distal esophagus.
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Acid rigor
Coagulation of muscle protein induced by acids.
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Acid salt
A salt in which not all of the ionizable hydrogen of the acid is
replaced by the electropositive element; NaHSO4, KH2PO4.
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Acid tartrate
A salt of tartaric acid that contains an acid group still capable
of combining with a base; bitartrate.
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Acid tide
A temporary increase in the acidity of the urine that occurs during
fasting.
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Acid-base balance
The normal balance between acid and base in the blood plasma,
expressed in the hydrogen ion concentration or pH, resulting from
the relative amounts of acidic and basic materials ingested and
produced by body metabolism, compared with the relative amounts of
acidic and basic materials excreted from the body and consumed by
body metabolism; the normal state of acid-base balance is not one
of neutrality, with equal concentrations of hydrogen and hydroxyl
ions, but a more alkaline state with a certain excess of hydroxyl
ions.
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Acid-citrate-dextrose
A citrate anticoagulant used for the collection and preservation of
whole blood.
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Acidemia
An increase in the H-ion concentration of the blood or a fall below
normal in pH. Individual types of acidemia are listed by specific
name, isovalericacidemia, aminoacidemia.
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Acid-etched restoration
The restoration of tooth structure with a resin after the surface
of the tooth has been treated with an acid solution that etches the
tooth surface, thereby increasing retention of the restoration.
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Acid-fast
Denoting bacteria that are not decolorized by acid-alcohol after
having been stained with dyes such as basic fuchsin; the
mycobacteria and nocardiae.
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Acid-fast stain
A test used to examine a specimen for the presence of
microorganisms, specifically mycobacteria that cause tuberculosis.
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Acidic
Having a pH of less than 7.
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Acidic amino acid
An amino acid with a second acid moiety, glutamic acid, aspartic
acid, and cysteic acid.
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Acidic dyes
Dyes that ionize in solution to produce negatively charged ions or
anions; they consist of sodium salts of phenols and carboxylic acid
dyes; their solutions tend to be neutral or slightly alkaline;
examples are eosin and aniline blue.
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Acidic stain
A dye in which the anion is the colored component of the dye
molecule, sodium eosinate (eosin).
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Acidified serum test
Lysis of the patient's red blood cells in acidified fresh serum,
specific for paroxysmal nocturnal hemoglobinuria.
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Acidify
1. To render acid. 2. To become acid.
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Acidity
1. The state of being acid. 2. The acid content of a fluid.
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Acid-loading test
A test to measure the ability of the renal tubules to acidify urine
in the presence of increased plasma acidity.
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Acidophil
1. A structure, cell, or other histologic element staining readily
with acidic dyes. 2. One of the acid-staining cells of the anterior
pituitary. 3. A microorganism that grows well in a highly acidic
medium.
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Acidophil adenoma
A tumor of the adenohypophysis in which cell cytoplasm stains with
acid dyes; often growth but not invariably produces hormone.
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Acidophil cell
A cell the cytoplasm or granules of which stain with acid dyes.
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Acidophil granule
A granule that stains with an acid dye such as eosin.
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Acidophilic
Having an affinity for acid dyes; denoting a cell or tissue element
that stains with an acid dye, such as eosin.
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Acidophilus
A helpful type of bacteria that crowds out harmful kinds, helps the
body fight disease and restore health, and acidifies the
colon. Manufactures most of the B vitamins in the body.
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Acidophilus milk
Milk inoculated with a culture of Bacillus acidophilus.
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Acidosis
An abnormal increase in the acidity of the body's fluids, caused
either by accumulation of acids or by depletion of bicarbonates.
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Acidotic
Abnormally high acidity of body fluids and tissues.
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Aciduria
1. Excretion of an acid urine. 2. Excretion of an abnormal amount
of any specified acid. Individual types of aciduria are prefixed by
the specific acid; aminoaciduria, ketoaciduria.
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Aciduric
Pertaining to bacteria that tolerate an acid environment.
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Acinar
Pertaining to the acinus.
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Acinar cell
Any secreting cell lining an acinus, applied especially to the
cells of the pancreas that furnish pancreatic enzymes, to
distinguish them from the cells of ducts and the pancreatic islets
of Langerhans.
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Acinar cell tumor
A solid and cystic tumor of the pancreas, occurring in young women;
tumor cells contain zymogen granules.
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Acinetobacter
A genus of nonmotile, aerobic bacteria (family Moraxellaceae)
containing gram-negative or -variable coccoid or short rods, or
cocci, often occurring in pairs. Spores are not produced. These
bacteria grow on ordinary media without the addition of serum. They
are oxidase negative and catalase positive; carbohydrates are
oxidized or not attacked at all, and arginine dihydrolase is not
produced. They are a frequent cause of nosocomial infections; often
resistant to many antibiotics, they can also cause severe primary
infections in immunocompromised people. The type species is
Acinetobacter calcoaceticus.
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Acinetobacter calcoaceticus
A species of bacteria originally found in a quinate enrichment;
strains of this organism previously identified as Bacterium
anitratum were found in the genitourinary tract; it is the type
species of the genus Acinetobacter.
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Acini
Plural of acinus.
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Acinic cell adenocarcinoma
An adenocarcinoma arising from secreting cells of a racemose gland,
particularly the salivary glands.
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Acinous
Resembling an acinus or grape-shaped structure.
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Acinous gland
A gland in which the secretory unit(s) has a grapelike shape and a
very small lumen; the exocrine part of the pancreas.
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Acinus
One of the minute grape-shaped secretory portions of an acinous
gland.
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Acitretin
A substance that is used in the prevention of cancer and in the
treatment of psoriasis. It belongs to the family of drugs called
retinoids.
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Ackee poisoning
An acute and frequently fatal vomiting disease associated with
central nervous system symptoms and marked hypoglycemia, caused by
eating unripe ackee fruit of Blighia spaida, a tree common in
Jamaica.
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ACL
One of the ligaments in the knee, the ACL (anterior cruciate
ligament) crosses from bottom of the femur (the thigh bone) to the
top of the tibia (the main bone in the lower leg.) ACL injuries can
occur in a number of situations including sports, such as football.
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ACL injury
An anterior cruciate ligament (ACL) injury is a tear in the ACL.
The ACL is located in the middle of the knee joint and connects the
lower leg bone to the thigh bone and prevents the leg bone from
sliding too far forward at the knee, which would cause instability.
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Aclasis
A state of continuity between normal and abnormal tissue.
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ACLE
Abbreviation for acute cutaneous lupus erythromatous.
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ACLS
Abbreviation for advanced cardiac life support; includes
electricity (defibrillator) and drugs for life threatening
arrhythmias.
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Acme
The period of greatest intensity of any symptom, sign, or process.
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Acne
Localized skin inflammation as a result of overactivity of the oil
glands at the base of hair follicles. When these oil glands become
plugged up, the overactive oil glands become red and inflamed. Also
called pimples.
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Acne artificialis
Acne produced by external irritants, such as tar (chloracne), or by
normally orally administered drugs internally administered, such as
iodides or bromides.
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Acne cachecticorum
Acne occurring in persons who have a debilitating constitutional
disease; characterized by large, soft, purulent, ulcerative,
cystic, and scarred lesions.
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Acne ciliaris
Follicular papules and pustules on the free edges of the eyelids.
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Acne conglobata
Defined by boils in the sweat glands. These infections are most
common in the axillae (armpits), but can also be found in the groin
and around the nipples and anus, where a particular type of sweat
gland is located.
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Acne cosmetica
Low-grade, noninflammatory acne lesions resulting from repeated
application of comedogenic agents in cosmetics.
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Acne fulminans
Severe scarring acne associated with fever, polyarthralgia, crusted
ulcerative lesions, weight loss, and anemia.
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Acne generalis
Acne lesions involving the face, chest, and back.
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Acne hypertrophica
Acne vulgaris in which the lesions, on healing, leave hypertrophic
scars.
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Acne inversa
Defined by boils in the sweat glands. These infections are most
common in the axillae (armpits), but can also be found in the groin
and around the nipples and anus, where a particular type of sweat
gland is located.
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Acne keloid
A chronic eruption of fibrous papules that develop at the site of
deep folliculitis, usually on the back of the neck at the hairline.
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Acne medicamentosa
Acne caused or exacerbated by drugs, lithium, halogens, or
steroids.
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Acne neonatorum
A condition of neonates, characterized by papules, pustules, and
comedones on the forehead and cheeks, usually resolving in a few
months.
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Acne punctata
Acne with black open comedones.
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Acne pustulosa
Acne vulgaris in which pustular lesions predominate.
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Acne varioliformis
A pyogenic infection involving follicles occurring chiefly on the
forehead and temples; involution of the umbilicated and crusting
lesions is followed by scar formation.
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Acne vulgaris
An eruption, predominantly of the face, upper back, and chest,
composed of comedones, cysts, papules, and pustules on an
inflammatory base; the condition occurs in a majority of people
during puberty and adolescence, due to androgenic stimulation of
sebum secretion, with plugging of follicles by keratinization,
associated with proliferation of Propionibacterium acnes.
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Acneform
Resembling acne.
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Acnemia
1. Congenital absence of legs. 2. Atrophy of the muscles of the
calves of the legs.
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ACNM
Abbreviation for American College of Nuclear Medicine.
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ACNP
Abbreviation for American College of Nuclear Physicians.
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ACOG
Abbreviation for the American College of Obstetricians and
Gynecologists.
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Acokanthera
Juice from the leaves and stems of Acokanthera ouabaio (family
Apocynaceae) and related species; an African arrow poison
containing ouabain.
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Acolous
Without limbs.
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Aconite
The dried root of Aconitum napellus (family Ranunculaceae),
commonly known as monkshood or wolfsbane; a powerful and
rapid-acting poison formerly used as an antipyretic, diuretic,
diaphoretic, anodyne, cardiac, and respiratory depressant, and
externally as an analgesic.
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Aconitine
The exceedingly poisonous active principle (diterpene alkaloid) of
Aconitum sp. and Delphinium sp., formerly used as a cardiac
sedative and applied externally for neuralgia.
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Acorea
Congenital absence of the pupil of the eye.
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Acorn-tipped catheter
A catheter used in ureteropyelography to occlude the ureteral
orifice and prevent backflow from the ureter during and following
the injection of an opaque medium.
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Acoustic
Having to do with sound or hearing.
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Acoustic agraphia
Inability to write from dictation.
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Acoustic area
In the brain, the floor of the lateral recess of the fourth
ventricle, extending medially to the limiting sulcus and overlying
the cochlear and vestibular nuclei of the rhombencephalon.
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Acoustic cell
A hair cell of the spiral organ.
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Acoustic enhancement
A manifestation of increased echo amplitude returning from regions
beyond an object, such as a fluid-filled cyst, which causes little
or no attenuation of the ultrasound beam.
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Acoustic impedance
The resistance that a material offers to the passage of a sound
wave (colloquial); a property of a medium computed as the product
of density and sound propagation speed (characteristic acoustic
impedance).
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Acoustic lens
In ultrasonography, a lens used to focus or diverge a sound beam;
may be simulated by electronic manipulation of signals.
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Acoustic nerve
A almost obsolete term still sometimes used incorrectly to
designate the vestibulocochlear nerve.
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Acoustic neurilemoma
Schwannoma arising from cranial nerve VIII.
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Acoustic neurofibromatosis
A genetic condition in which tumors form on the nerves of the inner
ear and cause loss of hearing and balance. Tumors may also occur in
the brain and on nerves in the skull and spinal cord, and may cause
loss of speech, eye movement, and the ability to swallow. Also
called neurofibromatosis type 2.
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Acoustic neuroma
A benign (non-cancerous) tumor on the eighth cranial nerve leading
from the brainstem to the ear.
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Acoustic pressure
In ultrasound, the instantaneous value of the total pressure minus
the ambient pressure; unit is pascal (Pa).
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Acoustic radiation
The fibers that pass from the medial geniculate body to the
transverse temporal gyri of the cerebral cortex by way of the
sublentiform part or limb of the internal capsule.
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Acoustic reference level
The biological reference level for sound measurements.
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Acoustic reflex
Contraction of the stapedius muscle in response to intense sound,
increasing impedance of the middle ear and thereby protecting the
inner ear from the sound.
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Acoustic shadow
Sonographic appearance of reduced echo amplitude from regions lying
beyond an attenuating object.
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Acoustic stimulation test
A test for fetal well-being in which an acoustic device is used to
stimulate the fetus and accelerate its fetal heart rate.
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Acoustic teeth
Tooth-shaped formations or ridges occurring on the vestibular lip
of the limbus laminae spiralis of the cochlear duct.
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Acoustic tetanus
Experimental tetanus induced by a faradic current, the speed of
which is estimated by the pitch of the vibrations.
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Acoustic tolerance
The maximum sound pressure level that can be experienced without
producing pain or permanent hearing threshold shift in a normal
individual.
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Acoustic trauma
An injury to the hearing mechanisms within the inner ear, caused by
excessively loud noise.
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Acoustic trauma hearing loss
Sensory hearing loss resulting from exposure to high-intensity
noise.
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Acousticofacial ganglion
A primordial ganglionic cell mass in early embryos that later
separates into the acoustic or spiral ganglion of the
vestibulocochlear (eighth cranial) nerve and the geniculate
ganglion of the facial (seventh cranial) nerve.
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Acousticophobia
Morbid fear of sounds.
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ACP
Abbreviation for acyl carrier protein; American College of
Physicians.
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ACP-acetyltransferase
Enzyme that transfers acetyl group from acetyl-CoA to ACP and
releases CoA to begin fatty acid synthesis.
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ACP-malonyltransferase
An enzyme that transfers malonyl group from malonyl-CoA to ACP and
releases free CoA, a key step in fatty acid synthesis.
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ACPS
Abbreviation for acrocephalosyndactyly.
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Acquired
In medicine, the word "acquired" means "new" or "added." New in the
sense that it is not genetic (inherited) and added in the sense
that is was not congenital (present at birth), but came along
later. For example, AIDS is an acquired, not a genetic form of
immune deficiency.
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Acquired ataxia
A generic term used to describe cerebellar syndromes related to
various environmental agents or to other diseases (ethanol
consumption, medications, anticonvulsants, infections [principally
viral], tumors, cerebral vascular disease, multiple sclerosis, and
autoimmune mechanisms).
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Acquired hemolytic anemia
Nonhereditary acute or chronic anemia associated with or caused by
extracorpuscular factors, certain infectious agents, chemicals
(including autoantibodies or therapeutic agents), burns, and toxic
materials from higher plant and animal forms (including snake
venoms).
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Acquired hemolytic icterus
Icterus and anemia occurring in association with a moderate degree
of splenomegaly, increased fragility of red blood cells, and
increased amounts of urobilin in the urine.
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Acquired hypelipoproteinemia
Nonfamilial hyperlipoproteinemia that develops as a consequence of
some primary disease, such as thyroid deficiency.
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Acquired ichthyosis
A thickening and scaling of the skin associated with some malignant
diseases (Hodgkin lymphoma), leprosy, and severe nutritional
deficiencies.
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Acquired Immune Deficiency Syndrome
Abbreviated as AIDS. A disease caused by human immunodeficiency
virus (HIV). The syndrome of opportunistic infections that occur as
the final stage of infection by HIV. The virus attaches to the CD4
receptor on T lymphocytes, causing their destruction and a
progressive loss of immune function. People with AIDS are at an
increased risk for developing certain cancers and infections that
usually occur only in individuals with a weak immune system.
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Acquired immunity
Resistance resulting from previous exposure of an individual in
question to an infectious agent or antigen; it may be active and
specific, as a result of naturally acquired (apparent or
inapparent) infection or intentional vaccination (artificial active
immunity); or it may be passive, being acquired through transfer of
antibodies from another person or from an animal, either naturally,
as from mother to fetus, or by intentional inoculation (artificial
passive immunity).
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Acquired megacolon
Megacolon occurring in association with an acquired disease; occurs
in inflammatory bowel disease (toxic megacolon) and Chagas disease
(South American trypanosomiasis).
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Acquired methemoglobinemia
Methemoglobinemia caused by various chemical agents, such as
nitrites or topical anesthetics.
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Acquired nevus
A melanocytic nevus that is not visible at birth, but appears in
childhood or adult life.
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Acquired pellicle
A thin film (about 1 mcm), derived mainly from salivary
glycoproteins, that forms over the surface of a cleansed tooth
crown when it is exposed to the saliva.
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Acquired platelet function defect
Non-hereditary diseases or associated conditions that cause the
platelets to not function properly.
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Acquired ptosis
A heterogeneous disorder caused by neurogenic (Horner syndrome),
myogenic (myasthenia gravis), traumatic, or mechanical causes.
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Acquired tufted angioma
Enlarging erythematous macules and plaques in children and adults,
composed microscopically of lobules of capillaries and spindle
cells that project into thin-walled venular dermal clefts.
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Acquisition
In psychology, the empiric demonstration of an increase in the
strength of the conditioned response in successive trials of
pairing the conditioned and unconditioned stimuli.
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ACR
Abbreviation for American College of Radiology.
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Acral
Relating to or affecting the peripheral parts, limbs, fingers,
ears, etc.
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Acral lentiginous melanoma
A form of malignant lentigo melanoma that occurs in palms, soles,
and subungual areas.
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Acrania
A group of the phylum Chordata; its members possess a notochord,
gill slits, and nerve cord but no vertebrae, ribs, or skull;
Amphioxus, tunicates, and acorn worms.
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Acranial
Having no cranium; relating to acrania or an acranius.
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Acranius
A malformed fetus exhibiting acrania.
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Acrel ganglion
1. Pseudoganglion on the posterior interosseous nerve on the dorsal
aspect of the wrist joint. 2. A cyst on a tendon of an extensor
muscle at the level of the wrist.
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Acremonium
A genus of fungi (family Moniliaceae, order Moniliales) that causes
eumycotic mycetoma; three species, Acremonium falciforme,
Acremonium kiliense, and Acremonium recifei, produce whitish to
yellow grains in the tissues. Produces keratomycosis, occasionally
other infections, and the antibiotic cephalosporin.
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Acribometer
An instrument for measuring very minute objects.
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Acrid
A pungent biting taste that causes irritation.
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Acrid poison
A poison that causes destructive local irritation as well as
systemic effects.
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Acridine
A dye, dye intermediate, and antiseptic precursor (9-aminoacridine,
acriflavine, proflavine hemisulfate) derived from coal tar and
irritating to skin and mucous membranes; a potent mutagen.
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Acridine dyes
Derivatives of the compound acridine that are closely related to
xanthene; important as fluorochromes in histology, cytochemistry,
and chemotherapy; examples include acriflavine, acridine orange,
and quinacrine mustard.
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Acridine orange
A basic fluorescent dye useful as a metachromatic stain for nucleic
acids; also used in screening cervical smears for abnormal and
malignant cells, where unusual amounts of DNA and RNA occur during
proliferation and in tumors (DNA fluoresces yellow to green; RNA
fluoresces orange to red).
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Acridine yellow
A faintly yellow solution with strong bluish-violet fluorescence;
used as a topical antiseptic and as a fluorescent stain in
histology.
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Acriflavine
An acridine dye, formerly used as a topical and urinary antiseptic,
and also used as one of Kasten fluorescent Schiff reagents to
reveal polysaccharides and DNA.
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Acrimonia
In ancient humoral pathology, a sharp, pungent, disease-provoking
humor.
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Acrimony
The quality of being intensely irritant, biting, or pungent.
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Acritical
1. Not critical; not marked by crisis; denoting diseases
terminating by lysis. 2. Indeterminate, especially concerning
prognosis.
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Acro-
1. Extremity, tip, end, peak, topmost. 2. Extreme.
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Acroagnosis
Loss or impairment of the sensory recognition of a limb. Absence of
acrognosis.
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Acroanesthesia
Anesthesia of one or more of the extremities.
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Acroarthritis
Inflammation of the joints of the hands or feet.
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Acroasphyxia
Impaired digital circulation, possibly a mild form of Raynaud
disease, marked by a purplish or waxy white color of the fingers,
with subnormal local temperature and paresthesia.
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Acroataxia
Ataxia affecting the distal portion of the extremities (hands and
fingers, feet, and toes).
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Acroblast
Component of the developing spermatid composed of numerous Golgi
elements; it contains the proacrosomal granules.
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Acrobrachycephaly
Type of craniosynostosis with premature closure of the coronal
suture, resulting in abnormally short anteroposterior diameter of
the cranium (skull).
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Acrocentric
A chromosome with a centromere near one end. Down syndrome (trisomy
21) is due to an extra acrocentic chromosome.
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Acrocentric chromosome
A chromosome with the centromere placed very close to one end so
that the short arm is very small, and often has a satellite.
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Acrocephalopolysyndactyly
Rare autosomal disorder with mental retardation, syndactyly,
oxycephaly, congenital heart defects, mild obesity, and
hypogenitalism.
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Acrocephalosyndactyly
A group of congenital syndromes characterized by craniosynostosis
with abnormal head shape and cutaneous and/or bony syndactyly.
There are several types with most types inherited as autosomal
dominant.
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Acrocinesia
Excessive movement.
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Acrocontracture
Contracture of the joints of the hands or feet.
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Acrocyanosis
Blueness of the extremities (the hands and feet.)
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Acrocyanotic
Characterized by acrocyanosis.
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Acrodermatitis
A childhood skin condition that may be accompanied by mild symptoms
of fever and malaise. It may also be associated with hepatitis B
and other viral infections.
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Acrodermatitis chronica atrophicans
A gradually progressive late skin manifestation of Lyme disease,
appearing first on the feet, hands, elbows or knees, and composed
of indurated, erythematous plaques that become atrophic, giving a
tissue-paper appearance of the involved sites.
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Acrodermatitis enteropathica
A historic model for the therapy of genetic disease. In the 1950s
when inherited disorders were usually seen as hopeless, this
progressive hereditary (autosomal recessive) disease of children
was found treatable. Acrodermatitis enteropathica is characterized
by the simultaneous occurrence of skin inflammation (dermatitis)
and diarrhea. The skin on the cheeks, elbows, and knees and tissue
around the mouth and anus are inflamed. There is also balding of
the scalp, eyebrows, and lashes, delayed wound healing, and
recurrent bacterial and fungal infections due to immune deficiency.
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Acrodermatosis
Any cutaneous affection involving the more distal portions of the
extremities.
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Acrodont
Tooth attachment in some lower vertebrates (mainly fish) in which
the teeth rest on the edge of the jaw bone rather than in sockets
or alveoli.
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Acrodynia
Pain in the extremities.
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Acrodysesthesia
Abnormal, unpleasant sensations in the peripheral portions of the
limbs.
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Acrodysostosis
An extremely rare congenital disorder characterized by abnormally
short and malformed bones of the hands and feet, small and
underdeveloped nose, and mental retardation. Other findings may
include progressive growth delays, short stature, and/or unusual
head and facial (craniofacial) features.
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Acroesthesia
1. An extreme degree of hyperesthesia. 2. Hyperesthesia of one or
more of the extremities.
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Acrofacial dysostosis
Mandibulofacial dysostosis associated with malformations of the
extremities (defective radius and thumbs), and radioulnar
synostosis.
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Acrogenous
Denoting conida of fungi produced by the conidiogenous cell at the
tip of a conidiophore.
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Acrogeria
Reduction or loss of subcutaneous fat and collagen of the hands and
feet, giving the appearance of premature aging.
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Acrognosis
Normal sensory perception of the extremities.
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Acrohyperhidrosis
Hyperhidrosis of the hands and feet.
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Acrohyperkeratosis
Thickening of the horny layer of the skin, usually nodular, of the
dorsum of the fingers and toes, and occasionally on the rim of the
ear and the tip of the nose.
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Acrokeratoelastoidosis
An autosomal dominant papular keratosis of the palms and soles,
with disorganization of dermal elastic fibers; a similar, but
acquired, condition may result from actinic damage of the hands.
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Acrokeratosis
Overgrowth of the horny layer of the skin, usually in nodular
configurations, of the dorsum of the fingers and toes, and
occasionally on the rim of the ear and tip of the nose.
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Acrokeratosis verruciformis of Hoff
Rare genodermatosis characterized by numerous flat warty papules on
the backs of the hands, insteps, knees, and elbows.
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Acromegalic
Pertaining to or characterized by acromegaly.
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Acromegalic gigantism
A form of pituitary gigantism in which the signs of acromegaly
accompany abnormal height.
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Acromegalogigantism
Gigantism in which enlarged facial features, disproportionately
enlarged limbs and other signs of acromegaly are prominent.
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Acromegaloidism
Rarely used term for a condition in which body proportions resemble
those of acromegaly.
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Acromegaly
A chronic metabolic disorder caused by the presence of too much
growth hormone. It results in gradual enlargement of body tissues
including the bones of the face, jaw, hands, feet, and skull.
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Acromelic
Affecting the terminal part of a limb.
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Acromesomelic dwarfism
A form of short-limb dwarfism characterized by pug nose and
shortening of the upper and lower extremities; particularly
striking in the distal portion of these extremities (forearm,
fingers of upper extremity and the lower leg and toes of the lower
extremity). Autosomal recessive inheritance.
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Acrometagenesis
Abnormal growth of the limbs resulting in malformation.
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Acromial anastomosis of the thoracoacromial artery
A vascular network between the acromion and the skin of the
shoulder, formed by anastomoses of the acromial branch of the
suprascapular artery with the acromial branch of the
thoracoacromial artery.
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Acromial angle
The prominent angle at the junction of the posterior and lateral
borders of the acromion.
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Acromial branch of suprascapular artery
Branch of suprascapular artery that pierces the origin of the
trapezius muscle to run to the acromion; anastomoses, acromial
branch of thoracoacromial artery.
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Acromial branch of thoracoacromial artery
A branch of the thoracoacromial artery that runs over the coracoid
process and under the deltoid muscle.
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Acromial end of clavicle
The flattened lateral end of the clavicle that articulates with the
acromion and is anchored to the coracoid process by the conoid and
trapezoid ligaments.
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Acromial facet of clavicle
A small oval facet on the lateral end of the clavicle for
articulation with the clavicular articular facet of the acromion.
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Acromial part of deltoid
Portion of deltoid (muscle) originating from the acromion.
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Acromial reflex
Contraction of the biceps muscle caused by a tap on the acromion or
the coracoid process.
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Acromicria
The antithesis of acromegaly; a condition in which the bones of the
face and limbs are small and delicate, possibly due to a deficiency
of somatotropin.
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Acromioclavicular
Relating to the acromion and clavicle; denoting the articulation
between the clavicle and the acromion of the scapula.
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Acromioclavicular joint
A plane synovial joint between the acromial end of the clavicle and
the medial margin of the acromion.
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Acromioclavicular ligament
A fibrous band extending from the acromion of the scapula to the
clavicle.
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Acromiohumeral
Relating to the acromion and the humerus.
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Acromion
The lateral extension of the spine of the scapula that projects as
a broad flattened process overhanging the glenoid fossa; it
articulates with the clavicle and gives attachment to part of the
deltoid muscles. Its lateral border is a palpable landmark ("the
point of the shoulder").
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Acromioplasty
A surgical reshaping of the acromion, frequently performed to
remedy compression of the supraspinatus portion of the rotator cuff
of the shoulder joint between the acromion and the greater tubercle
of the humerus.
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Acromioscapular
Relating to both the acromion and the body of the scapula.
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Acromphalus
Abnormal projection of the umbilicus.
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Acromyotonia
Myotonia affecting the limbs only, resulting in spastic deformity
of the hand or foot.
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Acroosteolysis
Congenital condition manifested by palmar and plantar ulcerating
lesions with osteolysis involving distal phalanges of the fingers
and toes.
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Acroparesthesia
1. Paresthesia of one or more of the limbs. 2. Nocturnal
paresthesia involving the hands, most often of middle-aged women;
formerly attributed to a lesion in the thoracic outlet but now
known to be a classic symptom of carpal tunnel syndrome.
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Acroparesthesia syndrome
Abnormal sensations such as numbness and tingling in the hands,
usually in middle-aged women; now known to be a classic symptom of
carpal tunnel syndrome.
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Acropetal
1. In a direction toward the summit. 2. Produced successively
toward the apex, with the youngest conidium formed at the tip and
the oldest at the base of a chain of conidia; pertaining to asexual
spore production in fungi by successive budding of the distal spore
in a spore chain.
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Acrophobia
Morbid fear of heights.
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Acropigmentation
Punctate and reticulate hyperpigmentation of the dorsal surfaces of
the fingers and toes beginning in early childhood and usually
increasing with age; more common in people with dark complexions of
Asian descent.
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Acropleurogenous
Denoting spores developing at the tip and along the sides of fungal
hyphae.
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Acropustulosis
Pustular eruptions of the hands and feet, often a form of
psoriasis.
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Acro-sage
A "combination of massage, yoga, and gymnastics," according to an
edition of the TV magazine Strange Universe UPN broadcast on
November 29, 1996. Former circus performer Benjamin Marantz created
the method. Apparently, it is a purported way to "reverse aging."
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Acrosclerosis
Stiffness and tightness of the skin of the fingers, with atrophy of
the soft tissue and osteoporosis of the distal phalanges of the
hands and feet; a limited form of progressive systemic sclerosis
occurring with Raynaud phenomenon and scleroderma of the forearms.
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Acrosin
A serine proteinase in sperm (spermatozoa) similar in specificity
to trypsin.
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Acrosomal granule
The single enzyme-rich granule within an acrosomal vesicle, which
results from the coalescence of proacrosomal granules.
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Acrosomal vesicle
A vesicle derived from the Golgi apparatus during spermiogenesis
the limiting membrane of which adheres to the nuclear envelope;
together with the acrosomal granule within, it spreads in a thin
layer over the pole of the nucleus to form the acrosome (acrosomal
cap).
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Acrosome
A caplike organelle or saccule derived from Golgi elements that
surround the anterior two thirds of the nucleus of a sperm.
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Acrosomin
A lipoglycoprotein complex present in the acrosomal cap.
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Acrospiroma
A tumor of the distal dermal segment of a sweat gland.
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Acroteric
Relating to the extreme peripheral or apical parts, such as the
tips of the fingers and the toes or the end of the nose.
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Acrotheca
Former name for fungal species now placed in the genus
Rhinocladiella or Fonsecaea.
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Acrotic
Marked by great weakness or absence of the pulse; pulseless.
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Acrotism
Absence or imperceptibility of the pulse.
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Acrotrophodynia
Pain, paresthesia, sensory loss, and trophic changes affecting the
distal extremities, usually the feet, which can follow prolonged
exposure of the limbs to cold and moisture.
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Acrylamide
A carcinogen that forms in starchy foods cooked at high temperature
(fried potatoes, potato chips).
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Acrylate
A salt or ester of acrylic acid.
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Acrylic
Denoting certain synthetic plastic resins derived from acrylic
acid.
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Acrylic acids
A series of unsaturated aliphatic acids of the general formula
R=CH-COOH; the prototype, acrylic acid (R = CH2) or 2-propenoic
acid, is derived from propionic acid by reduction or from glycerol
by dehydration.
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Acrylic resin
A general term applied to a resinous material of the various esters
of acrylic acid; used as a denture base material, for other dental
restorations, and for trays.
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Acrylic resin base
A form made of acrylic resin molded to conform to the tissues of
the alveolar process and used to support the teeth of a prosthesis.
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Acrylic resin tooth
A tooth made of acrylic resin.
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Acrylic resin tray
A plastic impression tray used in dentistry; usually fashioned for
the individual patient from an autopolymerizing acrylic resin.
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Acrylonitrile
A substance used to make plastics, rubber, and textiles. Being
exposed to acrylonitrile may increase the risk of developing
certain cancers, such as lung, brain, or prostate cancer.
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ACT
Abbreviation for activated clotting time.
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ACTH
Abbreviation for adrenocortitrophic hormone. A hormone that
stimulates the secretion of epinephrine (adrenaline) as part of the
body's response to stress.
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ACTH stimulation test
A test that measures the ability of the adrenal cortex to respond
to ACTH (adrenocorticotropic hormone) by producing cortisol
appropriately.
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ACTH-producing adenoma
A pituitary tumor composed of corticotrophs that produce ACTH,
often but not invariably a basophilic adenoma; may give rise to
Cushing disease or Nelson syndrome.
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Actin
One of the protein components into which actomyosin can be split;
it can exist in a fibrous form (F-actin) or a globular form
(G-actin).
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Actin filament
One of the contractile elements in muscular fibers and other cells;
in skeletal muscle, the actin filaments are about 7.5 nm wide and 1
mcm long, and attach to the transverse Z filaments.
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Acting out
An overt act or set of actions that provides an emotional outlet
for the expression of emotional conflicts (usually unconscious).
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Actinic
Relating to the chemically active rays of the electromagnetic
spectrum.
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Actinic granuloma
An annular eruption on sun-exposed skin which microscopically shows
phagocytosis of dermal elastic fibers by giant cells and
histiocytes.
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Actinic keratitis
A reaction of the cornea to ultraviolet light.
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Actinic keratosis
Abnormal skin growth stimulated by ultraviolet radiation from
sunlight; may lead to a type of cancer called basal cell carcinoma.
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Actinic porokeratosis
A lesion that occurs on exposed areas of extremities primarily;
bears a resemblance to actinic keratosis, but the histologic
features are those of porokeratosis.
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Actinic ray
A light ray toward and beyond the violet end of the spectrum that
acts upon a photographic plate and produces other chemical effects.
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Actinic reticuloid
Chronic pruritic erythema beginning on sun-exposed areas in elderly
males, with marked thickening and ridging of exposed skin
simulating lymphoma; there is infiltration by atypical CD8-positive
T lymphocytes.
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Actinides
Those elements with atomic numbers 89 to 103, below the lanthanides
in the Periodic Table.
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Actinium
An element, atomic no. 89, atomic wt. 227.05; it possesses no
stable isotopes and exists in nature only as a disintegration
product of uranium and thorium.
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Actinium emanation
Radon-219.
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Actino
In botany, rayed or starlike.
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Actinobacillosis
A disease of cattle and swine, occasionally reported in humans,
caused by the bacterium Actinobacillus lignieresii. It affects the
soft tissues, often the tongue and cervical lymph nodes, where
granulomatous swellings form and eventually break down to form
abscesses.
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Actinobacillus
A genus of small, nonmotile, non-spore-forming, aerobic,
facultatively anaerobic bacteria containing gram-negative rods
interspersed with coccal elements. The metabolism of these bacteria
is fermentative. They are pathogenic to animals. The type species
is Actinobacillus lignieresii.
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Actinobacillus lignieresii
A species that produces infections of the upper alimentary tract
and mouth in cattle and swine (actinobacillosis) and suppurative
lesions in the skin and lungs of sheep; it is the type species of
its genus.
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Actinohematin
A red respiratory pigment found in certain forms of Actinia (sea
anemones).
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Actinomadura
A genus of aerobic gram-positive, branching, nonacidfast
filamentous bacteria; it may form aerial hyphae and may contain
chains of up to 15 spores.
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Actinomadura africana
A bacterial species found in cases of mycetoma of the foot in
Africa.
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Actinomadura latina
A species of bacteria associated with mycetoma in South America.
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Actinomycelial
Relating to the mycelium-like filaments of the Actinomycetales.
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Actinomyces
A genus of slow-growing, nonmotile, nonsporeforming, anaerobic to
facultatively anaerobic bacteria (family Actinomycetaceae)
containing gram-positive, irregularly staining filaments;
diphtheroid cells may be predominant.
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Actinomyces bernardiae
Formerly termed CDC Coryneform, group 2.
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Actinomyces bovis
A species of bacteria that causes actinomycosis in cattle;
infection in humans is not established; it is the type species of
its genus.
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Actinomyces dentricolens
A bacterial species that causes dental plaque in cattle.
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Actinomyces georgiae
A species found in human gingival crevices.
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Actinomyces gerencaeriae
A species found in human periodontal flora.
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Actinomyces hordeovulneris
A species found in canine infections.
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Actinomyces howellii
A species that causes dental plaque in cattle.
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Actinomyces hyovaginales
A species found in pig vagina.
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Actinomyces israelii
The most common species of actinomyces causing human actinomycosis;
it also occasionally infects cattle.
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Actinomyces meyeri
A species found in human periodontal sulcus; in abscesses of brain,
and in head and neck infections.
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Actinomyces naeslundii
A species the natural habitat of which is the oral cavity; human
infections occur; may sometimes lead to periodontitis in other
animal species.
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Actinomyces neuii anitratus
Formerly CDC Coryneform group 1 like; found in human sources.
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Actinomyces neuii neuii
Formerly CDC Coryneform group 1; found in human sources.
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Actinomyces odontolyticus
A species the normal habitat of which is the human oral cavity; it
has been isolated from deep dental caries.
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Actinomyces pyogenes
Formerly Corynebacterium pyogenes; found in human sources.
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Actinomyces slakii
A species that causes dental plaque in cattle.
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Actinomyces suis
A strain formerly called Eubacterium suis; found in pigs.
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Actinomyces viscosus
A species that has been isolated from the oral cavity of humans and
some species of other animals; it produces periodontal disease in
animals and has been isolated from human dental calculus and root
surface caries.
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Actinomycetaceae
A family of nonsporeforming, nonmotile, ordinarily facultatively
anaerobic (some species are aerobic and others are anaerobic)
bacteria (order Actinomycetales) containing gram-positive,
non-acid-fast, predominantly diphtheroid cells that tend to form
branched filaments in tissue or in some stages of cultural
development.
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Actinomycetales
An order of bacteria consisting of moldlike, rod-shaped, clubbed,
or filamentous forms with decided tendency to true branching,
without endospores, but sometimes developing conidia; it includes
the families Mycobacteriaceae, Actinomycetaceae, and Nocardiaceae.
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Actinomycetemcomitans
Species of doubtful taxonomic position; frequently associated with
some forms of human periodontal disease as well as subacute and
chronic endocarditis; occurs with actinomycetes in actinomycotic
lesions.
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Actinomycetes
A term used to refer to members of the genus Actinomyces; sometimes
improperly used to refer to any member of the family
Actinomycetaceae or order Actinomycetales.
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Actinomycetoma
Mycetoma caused by higher bacteria.
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Actinomycin A
The first of the actinomycins isolated in crystalline form.
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Actinomycin F1
Produced by actinomycin C-elaborating strains of Streptomyces
chrysomallus; used as an antineoplastic agent.
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Actinomycins
A group of peptide antibiotic agents, isolated from several species
of Streptomyces (originally Actinomyces), which are active against
gram-positive bacteria, fungi, and neoplasms.
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Actinomycosis
A disease primarily of cattle and humans caused by the bacterium
Actinomyces bovis in cattle and by A. israelii and Arachnia
propionica in humans.
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Actinomycotic
Relating to actinomycosis.
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Actinomycotic appendicitis
Chronic suppurative appendicitis resulting from infection by
Actinomyces israelii.
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Actinomyxidia
A sporozoan order with a double cellular envelope, three polar
capsules, and eight spores; parasitic chiefly in segmented worms,
such as the common earthworm.
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Actinophage
A virus specific for actinomycetes.
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Actinopoda
A class of Sarcodina having slender pseudopodia with a central
axial filament.
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Actinotherapy
In dermatology, sunlight or ultraviolet light therapy.
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Action
1. The performance of any of the vital functions, the manner of
such performance, or the result of the same. 2. The exertion of any
force or power, physical, chemical, or mental.
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Action current
An electrical current induced in muscle fibers when they are
effectively stimulated; normally it is followed by contraction.
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Action potential
The change in membrane potential occurring in nerve, muscle, or
other excitable tissue when excitation occurs.
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Action study
In cancer prevention clinical trials, a study that focuses on
finding out whether actions people take can prevent cancer.
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Activase
A protein that is made by the body and that helps dissolve blood
clots. It can also be made in the laboratory and is used in the
treatment of heart attack and stroke. It is also being studied in
the treatment of cancer. Activase belongs to the family of drugs
called systemic thrombolytic agents. Also called tissue plasminogen
activator (tPA), recombinant tissue plasminogen activator (r-tPA),
and Alteplase.
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Activate
In biology, to stimulate a cell in a resting state to become
active. This causes biochemical and functional changes in the
activated cell.
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Activated acetaldehyde
The activated form of acetaldehyde that is formed during the
decarboxylation of active pyruvate. Formed in alcohol fermentation
and in carbohydrate metabolism.
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Activated atom
An atom possessing supernormal energy as a result of energy inputs.
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Activated charcoal
Residue from destructive distillation of various organic materials,
treated to increase its adsorptive power; used to treat diarrhea,
as an antidote to various poisons, and in purification processes in
industry and research.
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Activated clotting time
The most common test used for coagulation time in cardiovascular
surgery.
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Activated fatty acid
A fatty acyl-coenzyme A thiol ester.
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Activated glucose
A nucleoside diphosphoglucose such as UDPglucose.
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Activated glycol aldehyde
An intermediate in carbohydrate metabolism and in
transketolization.
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Activated hydrogen
Hydrogen removed by a dehydrogenase, via a flavoprotein, from a
metabolite for transference to another substance with which it
combines.
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Activated macrophage
A mature macrophage, in an active metabolic state, that is
cytotoxic to tumor/target cells, usually following exposure to
certain cytokines.
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Activated partial thromboplastin time
The time needed for plasma to form a fibrin clot after the addition
of calcium and a phospholipid reagent; used to evaluate the
intrinsic clotting system.
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Activated sludge method
A method of sewage disposal in which sewage is treated with 15%
bacterially active liquid sludge, which is produced by repeated
vigorous aeration of fresh sewage to form floccules or sediment;
when this flocculation process is complete, the resulting activated
sludge contains large numbers of bacteria, together with yeasts,
molds, and protozoa, which actively effect the oxidation of organic
compounds; this mixture is piped to a sedimentation tank, the
effluent from which is completely treated sewage.
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Activation
1. The act of rendering active. 2. An increase in the energy
content of an atom or molecule, affected by means such as increased
temperature or absorption of light photons that renders that atom
or molecule more reactive. 3. Techniques of stimulating the brain
by light, sound, electricity, or chemical agents, to elicit
abnormal activity in the electroencephalogram. 4. Stimulation of
peripheral nerve fibers to the point that action potentials are
initiated. 5. Stimulation of cell division in an oocyte by
fertilization or by artificial means. 6. The act of making
radioactive.
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Activation analysis
The identification and quantification of unknown elements from
their characteristic emissions and decay constants after they have
been made radioactive by exposure to neutron or charged particle
radiation.
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Activation-induced cytidine deaminase
An enzyme implicated in the processes of somatic hypermutation and
isotope class switch, in the generation of high-affinity
antibodies.
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Activator
1. A substance that renders another substance (a catalyst) active,
or that accelerates a process or reaction. 2. The fragment produced
by chemical cleavage of a proactivator, that induces the enzymic
activity of another substance. 3. An apparatus for making
substances radioactive (a neutron generator or a cyclotron). 4. A
removable type of myofunctional orthodontic appliance that acts as
a passive transmitter of force, produced by the function of the
activated muscles, to the teeth and alveolar process that are in
contact with it. 5. A protein that binds to a DNA sequence before
RNA polymerase transcription, sometimes referred to as coactivator.
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Active agent
Any single, isolatable, bioactive substance that has an
identifiable pharmaceutical action.
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Active aldehyde
Any aldehyde derivative of thiamin pyrophosphate.
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Active anaphylaxis
Reaction following inoculation of antigen in a subject previously
sensitized to the specific antigen.
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Active carbon dioxide
Complex of N-carboxybiotin (biotin + CO2) and an enzyme; the form
in which carbon dioxide is added to other molecules in
carboxylations, to methylcrotonyl-CoA to form β-methylglutaconyl in
the catabolism of leucine, and to acetyl-CoA to form malonyl-CoA.
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Active caries
Microbially induced lesions of the teeth that are increasing in
size.
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Active center
The part of a macromolecule at which a substrate or ligand, on
binding, produces biologic activity; for an enzyme, this is the
catalytic center, the site on an enzyme that catalyzes the
reaction.
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Active congestion
Congestion due to an increased flow of arterial blood to a part.
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Active electrode
A small electrode with an exciting effect that is used to stimulate
or record potentials from a localized area.
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Active euthanasia
A mode of ending life in which the intent is to cause the patient's
death in a single act (also called mercy killing).
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Active formaldehyde
1. A hydroxymethyl derivative of tetrahydrofolate or thiamin
pyrophosphate. 2. N5,N10-methylenetetrahydrofolate.
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Active formate
N10-formyltetrahydrofolate or an equivalent oxidation product of
tetrahydrofolate.
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Active formyl
The formyl group taking part in transformylation reactions with a
folic acid derivative in the role of carrier.
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Active glycoaldehyde
A derivative formed in carbohydrate metabolism.
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Active hyperemia
Hyperemia resulting from an increased afflux of arterial blood into
dilated capillaries.
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Active imagery
Form of imagery that involves concentrating on a preselected image
to control a particular symptom.
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Active immunity
Immunity produced by the body in response to stimulation by a
disease-causing organism or other agent.
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Active immunization
The production of active immunity.
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Active ingredient
A substance found in plants that acts like a drug in the body.
Examples include caffeine, morphine, nicotine, quinine, and
strychnine. The term also applies to synthetic substances whose
structures resemble that of plant alkaloids.
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Active labor
Contractions resulting in progressive effacement and dilation of
the cervix.
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Active length-tension curve
The relationship between active isometric tension and preload (rest
length) for a contracting muscle.
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Active methyl
A methyl group attached to a quaternary ammonium ion or a tertiary
sulfonium ion that can take part in transmethylation reactions,
methyl groups in choline and in S-adenosyl-l-methionine, which are
thus methyl donors.
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Active movements
Performed voluntarily by a person with no or some assistance from a
practitioner. Types of active movements are free, assistive, and
resistive.
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Active mutant
A mutant with overt phenotypic expression.
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Active principle
A constituent of a drug, usually an alkaloid or glycoside, that is
largely responsible for conferring its characteristic therapeutic
properties.
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Active prophylaxis
Use of an antigenic (immunogenic) agent to stimulate the
immunologic mechanism.
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Active psychoanalysis
An older term for psychoanalysis in which the analyst intervenes
directly and actively in the patient's life, by making
prohibitions, assigning tasks.
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Active pyruvate
An intermediate formed in the oxidative decarboxylation of
pyruvate.
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Active range of motion
Amount of motion at a given joint when the subject moves the part
voluntarily.
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Active repressor
1. A repressor that combines directly with an operator gene to
repress the operator and its structural genes, thus repressing
protein synthesis; an active repressor may be repressed by an
inducer, with resulting protein synthesis. 2. A homeostatic
mechanism for regulation of inducible enzyme systems.
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Active site
That portion of an enzyme molecule at which the actual reaction
proceeds; considered to consist of one or more residues or atoms in
a spatial arrangement that permits interaction with the substrate
to effect its reaction.
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Active transport
Movement by a cell membrane of molecules against a concentration or
electrochemical gradient. Requiring metabolic work. Most amino
acids, some sugars, and various ions are actively transported.
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Active treatment
A therapeutic substance or course intended to ameliorate the basic
disease problem, as opposed to supportive or palliative treatment.
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Active vasoconstriction
Reduction of the caliber of a vessel caused by increased tonus of
smooth muscle in the vessel wall.
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Active vasodilation
Vasodilation caused by decreased tonus of smooth muscle in the
vessel wall.
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Activin
Placental hormone that reaches maximum levels in maternal serum
during labor; helps to regulate production of
gonadotropin-releasing hormones, human chorionic gonadotropin, and
steroids by the placenta.
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Activities of daily living
The things people normally do in daily living, including any daily
activity we perform for self-care (such as feeding ourselves,
bathing, dressing, grooming), work, homemaking, and leisure. The
ability or inability to perform ADLs can be used as a very
practical measure of ability/disability in many disorders.
Abbreviated ADLs.
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Activities of daily living scale
Assessment of more fundamental abilities for independent living
(e.g. dressing, feeding, bathing, and toileting).
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Activity
1. Electroencephalography. The presence of neurogenic electrical
energy. 2. Physical chemistry an ideal concentration for which the
law of mass action will apply perfectly; the ratio of the activity
to the true concentration is the activity coefficient (γ), which
becomes 1.00 at infinite dilution. 3. For enzymes, the amount of
substrate consumed (or product formed) in a given time under given
conditions; turnover number. 4. The number of nuclear
transformations (disintegrations) in a given quantity of a material
per unit time. Units: curie (Ci), millicurie (mCi), becquerel (Bq),
megabecquerel (MBq). 5. The state of being active.
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Activity, drug
A measure of the physiological response a drug produces in the
body. A less active drug produces less response and a more active
drug produces more response.
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Actoclampin
The ATP hydrolysis-dependent, affinity-modulated motor unit
responsible for generating expansile forces in actin-based
motility.
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Actomyosin
A protein complex composed of actin and myosin; it is the essential
contractile substance of muscle fiber, active with MgATP.
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Actos
A drug that is used to treat type 2 diabetes and is being studied
in the prevention of head and neck cancer. It may be able to stop
leukoplakia (a precancerous condition affecting the mouth) from
developing into cancer. It belongs to the family of drugs called
thiazolidinediones. Also called pioglitazone.
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Actual cautery
A cautery, such as an electrocautery, acting directly through heat
and not by chemical means.
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Actualism
Stepwise form of yoga developed over a quarter-century by Russell
Paul Schofield, a clairvoyant with doctorates in divinity,
naturopathy, and psychology. It involves "the laying-on of lighted
hands." Its theory posits a human "divine mind," whose "scope" is
infinite, and ki (a human life force.) Also called actualism
lightwork, agni yoga, fire yoga.
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Actualism bodywork
Component of Actualism supposedly designed to assist awakening the
body and its consciousness to the "indwelling Creator" and to the
love of this alleged entity. It includes "nerve work," which
purportedly helps to deepen one's enjoyment of "life-energies."
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Acuaria spiralis
A nematode parasite in the proventriculus, esophagus, and
sometimes, the intestine, of chickens, turkeys, pheasants, and
other birds.
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Acu-ball pressure self-treatment
Form of self-applied acupressure characterized by the use of soft
balls of solid rubber.
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Acu-diet
Subject of Dr. Bahr's Acu-Diet: Weight Loss at Your Fingertips
(William Morrow &Company, Inc.), by Munich-born Frank R. Bahr,
M.D. The acu-diet is a combination of diets, exercises, and
self-applied acupressure. According to acu-diet theory, one can
influence the "compulsive eating center" in one's brain simply by
massaging specific "acupressure points."
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Acuity
1. Sharpness, clearness, distinctness. 2. Severity.
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Aculeate
Pointed; covered with sharp spines.
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Acumentin
A neutrophil and macrophage motility protein that links to the
actin molecule to control filament length.
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Acu-meridian energy transmission bodywork
Component of the Er Mei Qi Gong Therapy External Energy Diagnosis
and Treatment system.
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Acuminate
Conical or pointed.
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Acuology
The study of the use of needles for therapeutic purposes, as in
acupuncture.
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Acupoint
Specific location at which treatment by acupuncture is delivered.
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Acupoint bloodletting
Form of bloodletting characterized by puncturing acupoints with
needles. Its common usage reportedly has various purposes,
including activation of blood, clearance of channels (meridians),
and reduction of hotness.
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Acupoint therapy
Mode of counseling psychology based partly on acupuncture theory
and promoted by Mitchell J. Rabin, M.A.
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Acu-Powder treatment
One of the "clinic services" offered by the School of Classical
Taoist Herbology, in Manhattan (New York City.) It involves
application of a "remarkable" herbal powder to acupoints.
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Acupressure
1. Any treatment that allegedly involves the surface stimulation of
acupoints digitally, manually, or with tools held in the hand.
Practitioners may be called "acupressurists." "G-jo" is Chinese for
"first aid." 2. An ancient Asian art involving applied pressure to
certain pressure points along the body to open energy flows,
release tension, and promote balance.
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Acupressure massage
Acupressure in the form of a massage (An Mo). Apparently, it is the
equivalent of amma. Acupressure massage purportedly is usable to
promote the flow of Qi (chi) through the "meridian system."
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Acupressure points
Specific points along the meridians that are used in traditional
Chinese medicine. Also called acupoints, they are employed in
acupuncture, acupressure, Chinese massage, and shiatsu.
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Acupressure touch
Gentle form of acupressure.
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Acupuncture
Technique for treating some painful conditions and for regional
anesthesia by passing long thin needles through the skin to
specific points. Needles of various shapes are inserted into the
skin with the purported aim of stimulating acupoints, which
supposedly enable direct influence of the flow of Qi (chi).
Practitioners may be called "acupuncturists" or "acupuncture
therapists." Most forms of acupuncture are unnaturalistic.
Neuro-electric acupuncture and New Scientific
ElectroAcupuncture-and, apparently, osteopuncture-are naturalistic.
(Also known as acupuncture therapy, Zhenjiu.)
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Acupuncture anesthesia
Use of acupuncture to relieve pain during surgery wherein the
patient is conscious, either in conjunction with or instead of
analgesics or chemical anesthetics. It was introduced in 1958 in
the People's Republic of China. Also known as acupuncture
analgesia, acupuncture assisted anesthesia, anesthetic acupuncture.
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Acupuncture cupping method
Combination of acupuncture and cupping.
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Acupuncture energetics
Practice of acupuncture with the intention of treating acupoints so
that they "resonate" with "archaic pathways" of the "bodymind." It
involves acupuncture imaging.
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Acupuncture imaging
Part of acupuncture energetics wherein the practitioner
simultaneously palpates an acupuncture "zone" and describes it to
the client in "energetic" terms. Joint focusing on "affected" zones
supposedly enables channeling of the client's "true healing
intention" to "appropriate" zones, which purportedly effects
"bodymind integration."
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Acupuncture osteopathy
A purported "meridian acupuncture" approach to releasing myofascial
"body constitutions," advanced by author Mark D. Seem, Ph.D.
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Acupuncture points
Specific locations along the skin where qi meridians purportedly
run closest to the surface of the body. These points are stimulated
by needles or touch to facilitate the circulation of qi and blood,
encourage proper organ function, relieve pain, encourage
homeostasis of hormone function and organ interaction, and give
symptomatic relief of pain.
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Acuscope therapy
Form of energy medicine (vibrational medicine) that allegedly
speeds healing of virtually any injury. Its centerpiece is the
Acuscope (also called the Electro-Acuscope™), a computerized device
that purportedly balances the body's electrical current.
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Acusis
The ability to perceive sound normally.
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Acustimulation
Mild electrical stimulation of acupuncture points to control
symptoms such as nausea and vomiting.
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Acu-Stop 2000
"Acupressure method" promoted by mail in 1993. It was a purported
sure-fire way to lose at least thirty pounds, fast, and without
exercise, pills, or much willpower. Acu-Stop 2000 involved keeping
an "acupressure-like device" of the same name in one's right ear
for a few minutes daily. Allegedly, stimulation of this "ear
piece": (a) stimulates "points" in the body that regulate appetite
and (b) "suppresses their activity."
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Acute
Having a short duration and relatively severe course. Referring to
a symptom or disorder that arises rapidly.
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Acute abdomen
Any serious acute intraabdominal condition (appendicitis) attended
by pain, tenderness, and muscular rigidity and for which emergency
surgery must be considered.
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Acute abscess
A recently formed abscess with little or no fibrosis in the wall of
the cavity.
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Acute adrenal crisis
A life-threatening state caused by insufficient levels of cortisol,
which is a hormone produced and released by the adrenal gland.
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Acute adrenocortical insufficiency
Severe adrenocortical insufficiency when an intercurrent illness or
trauma causes an increased demand for adrenocortical hormones in a
patient with adrenal insufficiency resulting from disease or use of
relatively large amounts of similar hormones as therapy;
characterized by nausea, vomiting, hypotension, and frequently
hyperthemia, hyponatremia, hyperkalemia, and hypoglycemia; can be
fatal if untreated. Death results from fulminant inflammation
and/or circulatory collapses (shock).
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Acute alcoholism
A temporary deterioration in mental function, accompanied by
muscular incoordination and paresis, induced by the rapid ingestion
of alcoholic beverages.
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Acute angle
Any angle measuring less than 90 degrees.
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Acute anterior poliomyelitis
A disease that results in death or irreversible damage of motor
cells in the cerebrum, brainstem, and spinal cord, caused by
infection with small RNA enteroviruses of the Picornaviridae group;
formerly due almost solely to one of three types of polio virus,
but now more often caused by coxsackieviruses types A and B, or
echoviruses.
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Acute appendicitis
Acute inflammation of the appendix, usually resulting from
bacterial infection, which may be precipitated by obstruction of
the lumen by a fecalith; variable symptoms often consisting of
periumbilical, colicky pain and vomiting may be followed by fever,
leukocytosis, persistent pain, and signs of peritoneal inflammation
in the right lower quadrant of the abdomen; perforation or abscess
formation is a frequent complication of delayed surgical
intervention.
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Acute ascending paralysis
A paralysis of rapid course beginning in the legs and involving
progressively the trunk, arms, and neck, ending sometimes in death
in 1-3 weeks; generally due to either fulminant Guillain-Barré
syndrome or an ascending necrotizing myelopathy.
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Acute ataxia
Generalized ataxia of abrupt onset, most often caused by drug
intoxications, poisonings, or vestibular neuronitis.
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Acute bacterial endocarditis
A type of severe bacterial endocarditis caused primarily by
pyogenic organisms such as hemolytic streptococci or staphylococci.
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Acute bulbar poliomyelitis
Poliomyelitis virus infection affecting nerve cells in the medulla
oblongata and producing paralysis of the lower motor cranial
nerves.
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Acute cellular rejection
Graft rejection that usually begins within 10 days after a graft
has been transplanted into a genetically dissimilar host. Lesions
at the site of the graft characteristically are infiltrated with
large numbers of lymphocytes and macrophages that cause tissue
damage.
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Acute cerebellar ataxia
A sudden onset of uncoordinated muscle movement.
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Acute chest syndrome
A syndrome occurring in association with sickle cell disease
defined by a new infiltrate on chest radiograph; associated with
one or more new symptoms: fever, cough, sputum production, dyspnea,
or hypoxia.
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Acute cholecystitis
A sudden inflammation of the gallbladder that causes severe
abdominal pain.
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Acute compression triad
The rising venous pressure, falling arterial pressure, and
decreased heart sounds of pericardial tamponade.
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Acute contagious conjunctivitis
An obsolete term for an acute conjunctivitis marked by intense
hyperemia and profuse mucopurulent discharge.
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Acute cystitis
An infection of the bladder. The bladder is the part of the urinary
tract that collects the urine from the kidneys.
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Acute decubitus ulcer
A severe form of bedsore, of neurotrophic origin, occurring in
hemiplegia or paraplegia.
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Acute delirium
Delirium of recent, rapid onset.
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Acute disseminated encephalomyelitis
An acute demyelinating disorder of the central nervous system in
which focal demyelination is present throughout the brain and
spinal cord. This process is common to postinfectious,
postexanthem, and postvaccinal encephalomyelitis.
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Acute epidemic leukoencephalitis
A disease characterized by acute onset of fever, followed by
convulsions, delirium, and coma, and associated with perivascular
demyelination and hemorrhagic foci in the central nervous system.
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Acute febrile neutrophilic dermatosis
A rare dermatosis, predominant in women, of rapid onset and
characterized by plaquelike lesions, usually multiple, on the face,
neck, and upper extremities, accompanied by conjunctivitis, mucosal
lesions, fever, malaise, arthralgia, and peripheral blood
neutrophilia in many cases; biopsy reveals polymorphonuclear
infiltrate of the dermis; rapid remission occurs with systemic
steroid therapy.
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Acute fibrinous pericarditis
The usual lesion of acute pericarditis in which inflammation
produces large quantities of fibrin.
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Acute fulminating meningococcemia
Rapidly moving systemic infection with Neisseria meningitidis,
usually without meningitis, characterized by rash, usually
petechial or purpuric, high fever, and hypotension. May lead to
death within hours.
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Acute glomerulonephritis
Glomerulonephritis that frequently occurs as a late complication of
pharyngitis or skin infection, due to a nephritogenic strain of
β-hemolytic streptococci, characterized by abrupt onset of
hematuria, edema of the face, oliguria, and variable azotemia and
hypertension; the renal glomeruli usually show cellular
proliferation or infiltration by polymorphonuclear leukocytes.
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Acute goiter
A goiter that develops very rapidly.
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Acute granulocytic leukemia
A cancer of the blood and bone marrow, in which the bone marrow
makes abnormal myeloblasts (a type of white blood cell), red blood
cells, or platelets.
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Acute hallucinatory paranoia
A form in which periods of hallucination occur in addition to the
delusions.
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Acute hemorrhagic conjunctivitis
Specific acute endemic conjunctivitis associated with eyelid
swelling, tearing, conjunctival hemorrhages, and follicles; usually
caused by Enterovirus type 70.
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Acute hemorrhagic encephalitis
Encephalitis of apoplectoid character resulting from blood
extravasation.
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Acute hemorrhagic pancreatitis
An acute inflammation of the pancreas accompanied by the formation
of necrotic areas and hemorrhage into the substance of the gland;
clinically marked by sudden severe abdominal pain, nausea, fever,
and leukocytosis; areas of fat necrosis are present on the surface
of the pancreas and in the omentum because of the action of the
escaped pancreatic enzyme (trypsin and lipase).
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Acute histoplasmosis
Histoplasmosis caused by inhalation of microconidia, resulting in
illness ranging from flulike symptoms to the acute diffuse
pneumonitis seen with heavy exposure. Often, following illness,
lesions heal, leaving calcified nodules.
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Acute illness
An illness that may cause severe symptoms but is of limited
duration. Term is also sometimes used to mean "severe." A condition
which is self-limiting and short-lived, generally only lasting a
few days to a couple of months.
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Acute inflammation
Any inflammation that has a fairly rapid onset, quickly becomes
severe, and is usually manifested for only a few days, but that may
persist for even a few weeks; characterized histologically by
edema, hyperemia, and inflitrates of polymorphonuclear leukocytes.
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Acute inflammatory demyelinating polyradiculoneuropathy
The classic type of Guillain-Barré syndrome, in which the
predominant type of underlying nerve fiber pathology is
demyelination.
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Acute interstitial nephritis
Interstitial nephritis with variable tubular damage and
infiltration by numerous neutrophils, resulting from bacterial
infection, urinary tract obstruction, or other causes (including
drugs), which may be hypersensitivity reactions; accompanied by
renal failure, fever, blood or tissue eosinophilia, and rash.
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Acute interstitial pneumonia
A severe and usually fatal form of pneumonia occurring primarily in
infants; usually considered a form of hypersensitivity pneumonitis.
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Acute interstitial pneumonitis
Usually considered a form of hypersensitivity pneumonitis.
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Acute invasive aspergillosis
An aggressive infection, particularly in severely immunocompromised
people, involving the invasion of blood vessels and tissue
infarction by Aspergillus fumigatus. The disease often mimics the
signs and symptoms of acute bacterial pneumonia.
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Acute isolated myocarditis
An acute interstitial myocarditis of unknown cause, the endocardium
and pericardium being unaffected.
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Acute leukemia
Cancer of the blood cells (leukemia) that characteristically comes
on abruptly and (if not treated) progresses rapidly.
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Acute lobar nephrosis
A severe, but localized bacterial infection of the renal parenchyma
that may produce a mass effect, simulating a renal abscess.
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Acute lymphoblastic leukemia
A cancer of the blood and bone marrow, in which the bone marrow
makes too many lymphocytes (a type of white blood cell.)
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Acute lymphocytic leukemia
A cancer of the blood and bone marrow, in which the bone marrow
makes too many lymphocytes (a type of white blood cell.)
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Acute malaria
Form of malaria that may be intermittent or remittent, consisting
of a chill accompanied and followed by fever with its attendant
general symptoms and terminating in a sweating stage; the
paroxysms, caused by release of merozoites from infected cells,
typically recur every 48 hours in tertian (malaria vivax or malaria
ovale) malaria, every 72 hours in quartan (malariae) malaria, and
at indefinite but frequent intervals, usually about 48 hours, in
malignant tertian (falciparum) malaria, but in many cases
periodicity is not well established.
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Acute mania
Sudden onset of a manic episode.
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Acute massive liver necrosis
A lesion with extensive and rapid death of parenchymal cells of the
liver, sometimes with fatty degeneration of the size of the organ;
the necrosis may result from fulminant viral infection or chemical
poisoning; associated with jaundice.
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Acute motor axonal neuropathy
An acute, pure motor axon-degenerating type of
polyradiculoneuropathy, a variant of Guillain-Barré syndrome; seen
principally in a seasonal pattern (spring or summer) among children
in rural China following epidemics of diarrhea caused by
Campylobacter jejuni.
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Acute mountain sickness
AMS. High-altitude sickness occurs when a person gets ill when
visiting areas higher than 6,000 to 8,000 ft. above sea level. This
condition usually strikes when a person who is not used to
high-altitudes flies into a high-altitude city; drives to a
high-altitude location; or hikes, skis or climbs in high mountains.
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Acute multifocal placoid pigment epitheliopathy
An acute disease manifested by rapid loss of vision, and
multifocal, cream-colored placoid lesions of the retinal pigment
epithelium; resolves with restoration of vision.
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Acute myeloblastic leukemia
A cancer of the blood and bone marrow, in which the bone marrow
makes abnormal myeloblasts (a type of white blood cell), red blood
cells, or platelets.
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Acute myelogenous leukemia
A cancer of the blood and bone marrow, in which the bone marrow
makes abnormal myeloblasts (a type of white blood cell), red blood
cells, or platelets.
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Acute myeloid leukemia
A cancer of the blood and bone marrow, in which the bone marrow
makes abnormal myeloblasts (a type of white blood cell), red blood
cells, or platelets.
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Acute necrotizing encephalitis
An acute form of encephalitis, characterized by destruction of
brain parenchyma; caused by herpes simplex and other viruses.
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Acute necrotizing hemorrhagic encephalomyelitis
A fulminating demyelinating disorder of the central nervous system
that affects mainly children and young adults. Almost always
preceded by a respiratory infection, characterized by the abrupt
onset of fever, headache, confusion, and nuchal rigidity, soon
followed by focal seizures, hemiplegia, or quadriplegia, brainstem
findings, and coma; the CSF shows evidence of an inflammatory
process; due to the massive destruction of the white matter of one
or both hemispheres, often accompanied by similar destruction of
the white matter of the brainstem and cerebellar peduncles; of
unknown etiology.
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Acute necrotizing myelitis
A spinal cord disorder, probably a demyelinating disease, that
affects people of all ages and both genders. Presents with abrupt
or more gradual onset with sensory abnormalities and upper motor
neuron weakness; soon a reflexic flaccid motor paralysis and
sphincter paralysis supervenes, which become permanent. In some
cases, bilateral or unilateral optic neuritis is associated.
Protein levels are increased in the cerebrospinal fluid and
mononuclear cells are present. At autopsy, the lesion has been
identified as a necrotizing hemorrhagic leukomyelitis.
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Acute nephrosis
Historic term for acute oliguric renal failure, from any cause
related to nephrosis.
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Acute nonlymphoblastic leukemia
A cancer of the blood and bone marrow, in which the bone marrow
makes abnormal myeloblasts (a type of white blood cell), red blood
cells, or platelets.
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Acute pain
Pain that comes on quickly, can be severe, but lasts a relatively
short time.
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Acute pharyngoconjunctival fever
Acute infection usually occurring in epidemic form, occurring in
older children and adults; characterized by fever, pharyngitis, and
conjunctivitis; acquired particularly in summer camps and swimming
pools and caused by several types of adenoviruses.
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Acute phase protein
Plasma proteins associated with inflammation including C-reactive
protein (CRP), mannose-binding protein, serum amyloid P component,
α1-antitrypsin, fibrinogen, ceruloplasmin, and complement
components C9 and factor B, the concentrations of which increase in
response to interleukins 1, 6, and 11.
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Acute phase reactants
A group of proteins that are produced and/or released in increased
concentrations during the acute phase reaction, including
fibrinogen; C-reactive protein; complement proteins B, C3, C4;
α2-acid glycoprotein, serum amyloid A, and proteinase inhibitors.
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Acute phase reaction
Reaction to the changes in synthesis of certain proteins within the
serum during an inflammatory response; this response provides rapid
protection for the host against microorganisms through nonspecific
defense mechanisms.
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Acute promyelocytic leukemia
Leukemia presenting as a severe bleeding disorder, with
infiltration of the bone marrow by abnormal promyelocytes and
myelocytes, a low plasma fibrinogen, and defective coagulation.
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Acute pulmonary alveolitis
Acute inflammation involving exudate into the pulmonary alveoli and
impaired gas exchange such as occurs in several interstitial lung
diseases, including diffuse alveolar damage, drug-induced lung
disease, and acute immunologic injury.
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Acute pyelonephritis
Acute inflammation of the renal parenchyma and pelvis characterized
by small cortical abscesses and yellowish streaks in the medulla
resulting from the accumulation of pus in the collecting tubules
and interstitial tissue.
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Acute radiation syndrome
A syndrome caused by exposure of the body to large amounts of
radiation (from certain forms of therapy, accidents, and nuclear
explosions). It is divided into three major forms that are, in
ascending order of severity: the hematologic, gastrointestinal, and
central nervous system-cardiovascular forms; its clinical
manifestations are divided into prodromal, latent, overt, and
recovery stages.
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Acute recurrent rhabdomyolysis
Repeated paroxysmal attacks of muscle pain and weakness followed by
passage of dark red-brown urine, often precipitated by intercurrent
illness and diagnosed by demonstration of myoglobin in the urine;
it is attributed to abnormal phosphorylase activity in skeletal
muscle, but there may be more than one biologic type; probably
autosomal recessive inheritance. In some cases, at least, there is
deficiency of carnitine palmitoyl transferase.
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Acute respiratory distress syndrome
A life-threatening lung condition. It is a form of breathing
failure that can occur in very ill or severely injured people. It
is not a specific disease. It starts with swelling of tissue in the
lungs and buildup of fluid in the tiny air sacs that transfer
oxygen to the bloodstream. This leads to low blood oxygen levels.
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Acute retinal necrosis
A viral syndrome occurring in immunocompetent patients,
characterized by peripheral retinal destruction that becomes
circumferential and leads to retinal detachment.
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Acute rheumatic arthritis
Arthritis resulting from rheumatic fever.
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Acute rhinitis
An acute inflammation of the mucous membrane of the nose, marked by
sneezing, lacrimation, and a profuse secretion of watery mucus;
usually associated with infection by one of the common cold viruses
of acute allergic rhinitis.
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Acute scalp celluitis
Deep inflammation of the scalp without suppuration.
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Acute schizophrenia
A disorder in which the symptoms of schizophrenia occur abruptly;
they may subside or become chronic.
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Acute sensory axonal motor neuropathy
An acute axon-degenerating polyradiculoneuropathy that affects both
motor and sensory fibers; a variant of Guillain-Barré syndrome.
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Acute splenic tumor
Acute splenitis, enlargement, and softening of the spleen, usually
resulting from bacteremia or severe bacterial toxemia.
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Acute stress disorder
1. Development of characteristic symptoms within the first 4 weeks
after a psychologically traumatic event that was outside the range
of usual human experience. These include dissociative phenomena
(numbing or detachment), decreased awareness of surroundings,
derealization, depersonalization, and selective amnesia;
reexperiencing the event and attempting to avoid stimuli
reminiscent of the trauma, marked anxiety, and various symptoms of
autonomic arousal. 2. A DSM diagnosis that is established when
specified criteria are met.
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Acute vestibular syndrome
Affected patients present with sudden onset of intense and
disabling vertigo. The vertigo is paroxysmal, aggravated by head
movement, and associated with nausea and vomiting. The patient
exhibits horizontal or torsional nystagmus or mixed
horizontotorsional nystagmus.
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Acute viral conjunctivitis
An epidemic inflammation of the conjunctiva marked by follicles,
especially in the lower fornix; may be caused by adenoviruses,
herpesvirus, and Newcastle disease virus.
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Acute zonal occult outer retinopathy
Syndrome characterized by acute loss of one or more zones of outer
retinal function, photopsia, minimal funduscopic changes, and
electroretinography abnormalities affecting one or both eyes.
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Acutherapy
Form of touch therapy developed by Jim Foster and taught by the
Myotherapy Institute Research Center, in Salt Lake City, Utah.
Foster reportedly discovered that gentle touching of specific areas
of the body removed pain almost magically. Acutherapy purportedly
uses the body's "reflex system" and "energy flows."
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Acu-yoga
Combination of self-applied acupressure and a group of yogic
postures and stretches. It supposedly activates the points and
"energy pathways" of acupuncture.
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Acyanotic
Characterized by absence of cyanosis.
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Acyclic
Not cyclic; denoting especially an acyclic compound.
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Acyclic compound
An organic compound in which the chain does not form a ring.
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Acyclovir
A drug used to treat viral infections. Also known as Zovirax.
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Acyl-
An organic radical derived from an organic acid by the removal of
the carboxylic hydroxyl group.
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Acyl carrier protein
One of the proteins of the complex in cytoplasm that contains all
of the enzymes required to convert acetyl-CoA (and, in certain
cases, butyryl-CoA or propionyl-CoA) and malonyl-CoA to palmitic
acid. This complex is tightly bound together in mammalian tissues
and in yeast, but that from Escherichia coli is readily
dissociated.
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Acyladenylate
A compound in which an acyl group is combined with AMP by
elimination of H2O from the carobxyl group and of the phosphate
residue of AMP, usually in the initial form of ATP; inorganic
pyrophosphate is eliminated in condensation.
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Acylated
Acid radical incorporated into an organic compound.
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Acylation
Introduction of an acyl radical into an organic compound or
formation of such a radical within an organic compound.
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Acyl-CoA
Condensation product of a carboxylic acid and coenzyme A; metabolic
intermediate of importance, notably in the oxidation and synthesis
of fats.
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Acyl-CoA dehydrongenase
Enzyme catalyzing the reversible reduction of enoyl-CoA derivatives
of chain length 4-16, with NADPH as the hydrogen donor, forming
acyl-CoA and NADP.
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Acyl-CoA synthetase
1. General term for enzymes that form acyl-CoA, now called ligases.
2. Specifically, long-chain fatty acid-CoA ligase.
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Acylmercaptan bond
A "high-energy" bond formed by the condensation of a carboxyl group
(-COOH) and a mercaptan (or thiol) group (-SH); widely formed in
the course of intermediary metabolism, notably in the oxidation of
fats, where the -SH is part of coenzyme A and the -COOH is part of
the fatty acid being oxidized.
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Acyltransferases
Enzymes catalyzing the transfer of an acyl group from an acyl-CoA
to various acceptors.
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Acystia
Congenital absence of the urinary bladder.
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AD
Abbreviation for atopic dermatitis. A noncontagious inflammation of
the skin, characterized chiefly by redness, itching, and the
outbreak of lesions that may discharge serous matter and become
encrusted and scaly. Also referred to as eczema.
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Ad lib
Abbreviation for L. ad libitum, freely, as desired.
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Ad sat
Abbreviation for L. ad saturatum, to saturation.
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Ad spermatogonia
Diploid spermatogenic cells located in the basal compartment of
seminiferous tubules, which form the precursors of primary
spermatocytes.
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ADA
1. Abbreviation for the American Dental Association. 2.
Abbreviation for the American Diabetes Association.
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Adacrya
Absence of tears; tearlessness.
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Adactylous
Without fingers or toes.
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Adamantiales-Behcet's syndrome
A rare, chronic disorder involving inflammation of blood vessels
throughout the body. It is marked by recurrent oral and genital
ulcers, and eye inflammation.
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Adamantine
Exceedingly hard; formerly used in reference to the enamel of the
teeth.
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Adam's apple
This familiar feature in front of the neck is due to forward
protrusion of the largest cartilage of the larynx. It takes its
name from the story that a piece of the forbidden fruit stuck in
Adam's throat.
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Adams-Stokes syncope
Syncope due to complete AV block.
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Adams-Stokes syndrome
Syndrome characterized by slow or absent pulse, vertigo, syncope,
convulsions, and sometimes Cheyne-Stokes respiration; usually
results from advanced AV block or sick sinus syndrome.
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Adansonian classifcation
The classification of organisms based on giving equal weight to
every character of the organism; this principle has its greatest
application in numeric taxonomy.
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Adaptation
1. Preferential survival of members of a species because of a
phenotype that enhances their capacity to withstand the
environment, including the ecology. 2. An advantageous change in
function or constitution of an organ or tissue to meet new
conditions. 3. Adjustment of the sensitivity of the retina to light
intensity. 4. A property of certain sensory receptors that modifies
the response to repeated or continued stimuli at constant
intensity. 5. The fitting, condensing, or contouring of a
restorative material, foil, or shell to a tooth or cast to ensure
close contact. 6. The dynamic process by which the thoughts,
feelings, behavior, and biophysiologic mechanisms of the person
continually adjust to a constantly changing environment. 7. A
homeostatic response.
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Adaptation diseases
Diseases falling theoretically into the Selye concept of the
general-adaptation syndrome. The courses of these diseases lay
within the organism's excessive and prolonged or deficient
(maladaptive) responses to stressors.
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Adapter
1. A connecting part, joining two pieces of apparatus. 2. A
converter of electric current to a desired form. 3. A single- or
double-stranded digodeoxynucleotide used to join two incompatible
ends of restriction fragments.
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Adaptin
A multisubunit complex of proteins that has a binding site for the
cytoplasmic aspect of cargo receptor molecules as well as a binding
site for clathrin molecules, thus facilitating the formation of a
clathrin coat around a vesicle; currently, four different types of
adaptins are known, each capable of binding with the cytoplasmic
aspect of the four different types of cargo receptors.
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Adaptive behavior
Any behavior that enables an organism to adjust to a particular
situation or environment.
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Adaptive hypertrophy
Thickening of the walls of a hollow organ, such as the urinary
bladder, when outflow is obstructed.
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Adaptive mutation
Useful mutations that seem to occur more frequently when needed.
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Adaptogen
1. An agent that increases the body's ability to adapt to
environmental and internal stress by strengthening the immune,
nervous, and glandular systems. It enhances an organism's
resistance to stress, disease, and the environment, as well as
normalizing metabolic functions and increasing metabolic
efficiency. 2. A prophylactic which heightens in an unspecific way
the resistance of the organism to various environmental influences
and stimuli and/or reduces the disposition or susceptibility to
illness. 3. A substance that is able to improve the ability of an
organism to adapt to differing external or internal disturbances.
4. Enhancement of the body's non-specific resistance to external
stresses or to noxious effects of physical, chemical, or biological
nature.
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Adaptogenic
Helping the human organism adapt to stressful conditions.
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Adaptogenic herbs
Herbs that help the body adapt to stress. These include herbs such
as ginseng, suma, astragalus reishi mushroom, spikenard, and
schizandra.
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Adaptometer
A device for determining the course of retinal dark adaptation and
for measuring the minimum light threshold.
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Adaptor hypothesis
A hypothesis, proposed by F.H.C. Crick, that an adaptor molecule
must be present between the information-containing DNA and the
protein being synthesized.
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ADAR
Shortened form of adenosine deaminase acting on RNA.
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Adaxial
Toward an axis, or on one or other side of an axis.
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ADC
Abbreviation for AIDS dementia complex.
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ADCC
Abbreviation for antibody-dependent cell-mediated cytotoxicity.
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Add
Abbreviation for L. adde, add; L. addantur, let them be added;
addendus, to be added; and addendo, by adding.
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ADD
Attention Deficit Disorder. An inability to control behavior due to
difficulty in processing neural stimuli.
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Added sugar
Saccharide compounds added to foods during preparation.
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Adder
Common name for many members of the family Viperidae (the vipers),
applied to several genera, although true adders are of the genus
Vipera.
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Adderall
A combination of drugs that is used as a treatment for attention
deficit hyperactivity disorder (ADHD) and narcolepsy (a sleep
disorder.) It belongs to the family of drugs called stimulants.
Also called dextroamphetamine-amphetamine.
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Addict
A person who is habituated to a substance or practice, especially
one considered harmful or illegal.
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Addiction
A state of physical and psychological dependence produced by
habitual use of certain drugs, with the core connotation of loss of
control over use.
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Addictive drug
Any drug that creates a certain degree of euphoria and has a strong
potential for addiction.
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Addis count
A quantitative enumeration of the red blood cell count, white blood
cell count, and casts in a 12-hour urine specimen; used to follow
the progress of known renal disease.
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Addison clinical planes
A series of planes used as landmarks in thoracoabdominal
topography.
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Addison's disease
A disease caused by failure of the adrenal glands, marked by lack
of appetite, weakness, digestive problems, and darkening of the
skin. Characterized by the chronic destruction of the adrenal
cortex, which leads to an increased loss of sodium and water in the
urine, muscle weakness, and low blood pressure. The bronze color of
the skin is due to the increased production of the skin pigment
melanin.
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Addisonian
Relating to or described by Thomas Addison; used in relation to the
various features of Addison disease.
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Addition compound
1. Strictly, a complex of two or more complete molecules in which
each preserves its fundamental structure and no covalent bonds are
made or broken (hydrates of salts, adducts). 2. Loosely,
association of acids with basic organic compounds (amines with
HCl). 3. More loosely, addition of two molecules without the loss
of any atom but resulting in formation of new covalent bonds
(CH2=CH2 + Br2 → BrCH2-CH2Br).
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Additive
1. A substance not naturally part of a material (food) but
deliberately added to fulfill some specific purpose (preservation).
2. Tending to add or be added; denoting addition. 3. In metric
studies (genetics, epidemiology, physiology, statistics), having
the property that the total combined effect of two or more factors
equals the sum of their individual effects in isolation.
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Additive effect
An effect wherein two or more substances or actions used in
combination produce a total effect, the same as the arithmetic sum
of the individual effects.
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Additive model
A model in which the combined effect of several factors is the sum
of the effects that would be produced by each of the factors in the
absence of the others.
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Additivity
The quality or state of being additive.
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Addressin
A molecule on the surface of a cell that serves as a homing device
to direct another molecule to a specific location.
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Addressin ligands
Ligands on cells for specific homing receptors on lymphocytes.
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Adducent
Bringing toward; adducting.
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Adducin
A membrane protein that binds to spectrin and actin and links the
spectrin assembly.
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Adduct
1. To draw toward the median plane. 2. An addition product, or
complex, or one part of the same.
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Adduction
Movement of a limb sideways toward the body.
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Adductor brevis
Muscle of medial (adductor) compartment of thigh; origin, superior
ramus of pubis; insertion, upper third of medial lip of linea
aspera; action, adducts thigh; nerve supply, obturator.
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Adductor canal
The space in middle third of the thigh between the vastus medialis
and adductor muscles, converted into a canal by the overlying
sartorius muscle. It gives passage to the femoral vessels,
saphenous nerve, and the nerve to the vastus medialis, ending at
the adductor hiatus.
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Adductor hallucis
Muscle of third layer of plantar muscles; origin, by two heads, the
transverse head from the capsules of the lateral four
metatarsophalangeal joints and the oblique head from the lateral
cuneiform and bases of the third and fourth metatarsal bones;
insertion, lateral side of base of proximal phalanx of great toe;
action, adducts great toe; nerve supply, lateral plantar.
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Adductor hiatus
The aperture in the aponeurotic insertion of the adductor magnus
that transmits the femoral artery and vein from the adductor canal
to the popliteal space.
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Adductor longus
Muscle of medial (adductor) compartment of thigh; origin,
symphysis, and crest of pubis; insertion, middle third of medial
lip of linea aspera; action, adducts thigh; nerve supply,
obturator.
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Adductor magnus
Muscle of medial (adductor) compartment of thigh; origin, ischial
tuberosity, and ischiopubic ramus; insertion, linea aspera, and
adductor tubercle of femur; action, adducts and extends thigh;
nerve supply, obturator, and sciatic.
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Adductor minimus
A small flat muscle of the medial (adductor) compartment of thigh
constituting the upper portion of the adductor magnus, insertion,
the space above linea aspera.
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Adductor muscle
Any muscle that pulls inward toward the midline of the body. For
example, the adductor muscles of the leg serve to pull the legs
together. The opposite of "adductor" is "abductor."
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Adductor pollicis
Intrinsic muscle of palm; origin, by two heads, the transverse head
from the shaft of the third metacarpal and the oblique head from
the front of the base of the second metacarpal, the trapezoid and
capitate bones; insertion, medial side of base of proximal phalanx
of thumb; action, adducts thumb; nerve supply, ulnar.
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Adductor reflex
Contraction of the adductors of the thigh caused by tapping the
tendon of the adductor magnus muscle while the thigh is abducted.
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Adductor spasmodic dysphonia
A form of spasmodic dysphonia in which excessive closure of the
vocal folds affects the initiation and maintenance of phonation.
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Adductor tubercle of femur
The prominence above the medial epicondyle of the femur to which
the tendon of the adductor magnus attaches.
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Ade
Abbreviation for adenine.
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Adelomorphous
Of a not clearly defined form. In the past this term was applied to
certain cells of the gastric glands.
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Adelophialide
Reduced form of a phialide lacking a basal septum. Seen in the
general Phialemonium and Lecythophora.
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Adenalgia
Rarely used term for pain in a gland.
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Adendritic
Without dendrites.
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Adenectomy
Excision of a gland.
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Adenectopia
Presence of a gland other than in its normal anatomic position.
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Adenemphraxis
Rarely used term for an obstruction to the discharge of a glandular
secretion.
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Adenine
6-aminopurine, one of the two purine bases of DNA and RNA.
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Adenine arabinoside
Misnomer for arabinosyladenine.
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Adenine deaminase
An enzyme that catalyzes the hydrolysis of adenine to ammonia and
hypoxanthine. A part of purine degradation.
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Adenine phosphoribosyltransferase
An enzyme that catalyzes the reaction of adenine with
5-phospho-α-d-ribose 1-diphosphate (PRPP) to form AMP and
pyrophosphate. An important step in purine salvage. A deficiency of
this enzyme can lead to 2,8-dihydroxyadenine lithiasis.
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Adenine sulfate
Adenine conjugated with sulfuric acid; used to stimulate leukocyte
production in agranulocytosis.
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Adenitis
Inflammation of a lymph node or of a gland.
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Adenization
Conversion into glandlike structure.
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Adeno-
Combining forms denoting gland, glandular; corresponds to L.
glandul-, glandi-.
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Adenoacanthoma
A malignant neoplasm consisting chiefly of glandular epithelium
(adenocarcinoma), usually well differentiated, with foci of
squamous (or epidermoid) neoplastic cells.
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Adenoblast
A proliferating embryonic cell with the potential to form glandular
parenchyma.
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Adenocarcinoma
A malignant adenoma arising from a glandular organ. Adenomas are
neoplasms of glandular epithelia.
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Adenocarcinoma in Barrett esophagus
An adenocarcinoma arising in the esophagus that has become lined
with columnar cells (Barrett mucosa).
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Adenocarcinoma in situ
A noninvasive, abnormal proliferation of glands believed to precede
the appearance of invasive adenocarcinoma; reported in the
endometrium, breast, large intestine, cervix, and other sites.
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Adenocarcoma
A malignant neoplasm arising simultaneously or consecutively in
mesodermal tissue and glandular epithelium of the same part.
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Adenocystoma
Adenoma in which the neoplastic glandular epithelium forms cysts.
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Adenocyte
A secretory cell of a gland.
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Adenodiastasis
Separation or ectopia of glands or glandular tissue from their
usual anatomic sites, pancreatic glands in the wall of the small
intestine, gastric glands in the wall of the esophagus.
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Adenodynia
Rarely used term for adenalgia.
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Adenofibroma
A benign neoplasm composed of glandular and fibrous tissues, with a
relatively large proportion of glands.
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Adenogenous
Having an origin from glandular tissue.
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Adenohypophysial
Relating to the adenohypophysis.
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Adenohypophysis
The anterior pituitary gland; it consists of the distal,
intermediate, and infundibular parts.
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Adenohypophysitis
Inflammatory and fibriotic reaction affecting the anterior
pituitary gland, often related to pregnancy.
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Adenoid cystic cancer
A rare type of cancer that usually begins in the salivary glands.
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Adenoid facies
The open-mouthed and often dull appearance in children with adenoid
hypertrophy, associated with a pinched nose.
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Adenoid tissue
Lymphatic tissue intimately associated with epithelium.
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Adenoid tumor
Adenoma, or neoplasm with glandlike spaces.
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Adenoidectomy
The surgical removal of the adenoids.
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Adenoiditis
Infection of the adenoids.
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Adenoids
Masses of lymphoid tissue in the upper part of throat behind the
nose.
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Adenoids and tonsils
These structures in the back of the throat are composed of tissue
similar to the lymph nodes or "glands."
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Adenolipoma
A benign neoplasm composed of glandular and adipose tissues.
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Adenolipomatosis
A condition characterized by development of multiple adenolipomas.
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Adenolymphocele
Cystic dilation of a lymph node following obstruction of the
efferent lymphatic vessels.
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Adenoma
A benign epithelial tumor having a glandular origin and structure.
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Adenoma sebaceum
Archaic misnomer for a hamartoma occurring on the face, composed of
fibrovascular tissue and appearing as an aggregation of red or
yellow papules that may be associated with tuberous sclerosis;
sebaceous glands may be present but are not increased.
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Adenomatoid
Resembling an adenoma.
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Adenomatoid odontogenic tumor
A benign epithelial odontogenic tumor appearing radiographically as
a well-circumscribed, radiolucent-radiopaque lesion usually
surrounding the crown of an impacted tooth in an adolescent or
young adult; characterized histologically by columnar cells
organized in a ductlike configuration interspersed with
spindle-shaped cells and an amyloidlike deposition that gradually
undergoes dystrophic calcification.
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Adenomatoid tumor
A small benign tumor of the male epididymis and female genital
tract, consisting of fibrous tissue or smooth muscle enclosing
anastomosing glandlike spaces containing acid mucopolysaccharide
lined by flattened cells that have ultra-structural characteristics
of mesothelial cells.
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Adenomatosis
A condition characterized by multiple glandular overgrowths.
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Adenomatous
Relating to an adenoma, and to some types of glandular hyperplasia.
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Adenomatous polyp
A polyp that consists of benign neoplastic tissue derived from
glandular epithelium.
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Adenomegaly
Enlargement of a gland.
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Adenomere
Structural unit in the parenchyma of a developing gland that
becomes the functional portion of the organ.
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Adenomyoma
A benign neoplasm of muscle (usually smooth muscle) with glandular
elements; occurs most frequently in the uterus and uterine
ligaments.
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Adenomyosis
Uterine thickening that occurs when endometrial tissue, which
normally lines the uterus, extends into the fibrous and muscular
tissue of the uterus.
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Adenomyosis uteri
A benign invasion of myometrium by endometrial tissue.
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Adenopathy
Swelling or enlargement of the lymph nodes.
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Adenophlegmon
Acute inflammation of a gland and the adjacent connective tissue.
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Adenophorasida
A class of nematodes lacking lateral canals opening into the
excretory system and phasmids, with few or no caudal papillae, eggs
unsegmented, and with polar plugs or hatching in utero. It includes
the genera Trichuris, Capillaria, and Trichinella among important
parasites of humans and domestic animals.
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Adenosine
A drug used to help a patient with supraventricular tachycardia
convert to normal sinus rhythm.
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Adenosine 3', 5'-cyclic monophospate
An activator of phosphorylase kinase and an effector of other
enzymes, formed in muscle from ATP by adenylate cyclase and broken
down to 5′-AMP by a phosphodiesterase; the first compound referred
to as a "second messenger." It is a metabolic regulator. A related
compound (2′,3′) is also known.
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Adenosine 3', 5'-cyclic phosphate phosphodiesterase
An enzyme that catalyzes the hydrolysis of adenosine 3′,5′-cyclic
phosphate forming 5′-AMP, a crucial step in the regulation of
cellular adenosine 3′,5′-cyclic phosphate levels, inhibited by
caffeine.
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Adenosine 3'-phosphate
3′-Adenylic acid.
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Adenosine 3'-phosphate 5'-phosphosulfate
An intermediate in the formation of urinary ethereal sulfates,
notable for containing a "high-energy" sulfate bond; the 3′-OH of
adenosine is replaced by -OPO3H2 and the 5′-OH by -OP(O2H)-OSO3H.
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Adenosine 5'-diphosphate
A condensation product of adenosine with pyrophosphoric acid,
formed from ATP by the hydrolysis of the terminal phosphoryl group
of the latter compound.
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Adenosine 5'-phosphate
5′-Adenylic acid.
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Adenosine 5'-phosphosulfate
An intermediate in the formation of PAPS (active sulfate).
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Adenosine 5'-phosphosulfate kinase
The enzyme that catalyzes the formation of active sulfate from
adenosine 5′-phosphosulfate and ATP.
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Adenosine 5'-triphosphate
Adenosine with triphosphoric acid esterified at its 5′ position;
immediate precursor of adenine nucleotides in RNA; the primary
energy currency of a cell.
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Adenosine deaminase
An enzyme found in mammalian tissues, capable of catalyzing the
deamination of adenosine, forming inosine and ammonia. A deficiency
of adenosine deaminase can lead to one form of severe combined
immunodeficiency disease.
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Adenosine kinase
An enzyme catalyzing the transfer of a phosphate group from MgATP
to adenosine, forming MgADP and AMP, an important step in
nucleoside salvage and regulation.
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Adenosine monophosphate
Specifically, adenosine 5′-monophosphate.
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Adenosine nucleosidase
An enzyme hydrolyzing adenosine to adenine and d-ribose.
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Adenosine phosphate
Specifically, adenosine 2′-, 3′-, or 5′-phosphate.
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Adenosine tetraphosphate
A condensation product of adenosine with tetraphosphoric acid at
the 5′ position.
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Adenosine triphosphatase
An enzyme that catalyzes the release of the terminal phosphate
group of adenosine 5′-triphosphate; visualized cytochemically in
various cell membranes, mitochondria, and in the A band of striated
muscle sarcomeres associated with myosin.
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Adenosine triphosphate
Abbreviated as ATP. A substance present in all living cells that
provides energy for many metabolic processes and is involved in
making RNA. ATP made in the laboratory is being studied in patients
with advanced solid tumors to see if it can decrease weight loss
and improve muscle strength.
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Adenosis
1. A rarely used term for a generalized glandular disease. 2.
Glandular tissue in one or more sites in which it is not usually
found.
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Adenosquamous carcinoma
A type of lung tumor exhibiting areas of clear-cut glandular and
squamous cell differentiation.
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Adenosyl
The radical of adenosine minus an H or OH from one of the ribosyl
OH groups, usually the 5′, S-adenosyl-l-methionine.
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Adenosylcobalamin
A derivative of vitamin B12; its impaired biosynthesis can lead to
methylmalonic acidemia.
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Adenotomy
Incision of a gland.
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Adenotonsillectomy
Operative removal of tonsils and adenoids.
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Adenous
Rarely used term for adenose.
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Adenoviridae
A family of double-stranded DNA viruses, commonly known as
adenoviruses, that develop in the nuclei of infected cells in
mammals and birds. The virion is 70-90 nm in diameter, naked, and
ether resistant; the capsids are icosahedral and composed of 252
capsomeres. The family includes two genera, Mastadenovirus and
Aviadenovirus.
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Adenovirus
A group of viruses that cause respiratory tract and eye infections.
Adenoviruses used in gene therapy are altered to carry a specific
tumor-fighting gene.
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Adenyl
The radical or ion of adenine; often used for adenylyl, as in
adenylosuccinic acid.
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Adenyl cyclase
An enzyme that converts adenosine monophosphate to 3′,5′-cyclic
adenosine monophosphate, an intracellular second messenger of
neural and hormonal activation.
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Adenylate
Salt or ester of adenylic acid.
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Adenylate cyclase
An enzyme acting on ATP to form 3′,5′-cyclic AMP plus
pyrophosphate, a crucial step in the regulation and formation of
second messengers.
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Adenylate kinase
A phosphotransferase that catalyzes the reversible phosphorylation
of a molecule of ADP by MgADP, yielding MgATP and AMP.
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Adenylic acid
A condensation product of adenosine and phosphoric acid; a
nucleotide found among the hydrolysis products of all nucleic
acids. 3′-Adenylic acid (adenosine 3′-monophosphate) and
5′-adenylic acid [adenosine 5′-monophosphate (AMP)] differ in the
place of attachment of the phosphoric acid to the d-ribose;
deoxyadenylic acid differs in having H instead of OH at the 2′
position of d-ribose.
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Adenylosuccinate lyase
An enzyme catalyzing the nonhydrolytic cleavage of adenylosuccinic
acid producing AMP and fumarate and also of
4-(N-succinocarboxamido)-5-aminoimidazole nucleotide to yield
fumarate and aminoimidazole carboxamide ribosyl-5-phosphate. Both
are steps in purine nucleotide biosynthesis.
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Adenylosuccinate synthase
A ligase catalyzing the formation of adenylosuccinate, GDP, and
phosphate from inosinic acid, aspartate, and GTP; an important
enzyme in purine nucleotide biosynthesis.
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Adenylosuccinic acid
A condensation product of aspartate and inosine 5′-monophosphate;
an intermediate in the biosynthesis of adenylic acid. Formally, it
is adenylic acid with succinic acid replacing an H of the NH2
group.
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Adenylyl
The radical of adenylic acid minus an OH from the phosphoryl group;
often shortened to adenyl in compound names, such as
adenylosuccinic acid.
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Adenylyl cyclase
Former name for adenylate cyclase.
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Adeps
1. Denoting fat or adipose tissue. 2. The rendered fat of swine,
lard, used in the preparation of ointments.
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Adeps lanae
The greasy substance obtained from the wool of the sheep Ovis aries
(family Bovidae). Used as an emollient base for creams and
ointments.
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Adeps renis
Obsolete term for the layer of adipose tissue ("fatty capsule")
surrounding the kidney (perirenal fat).
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Adequal cleavage
Cleavage resulting in the formation of blastomeres of approximately
equal size.
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Adequate intake
An FDA-recommended average daily nutrient intake level based on
observed or experimentally determined approximations or estimates
of nutrient intake by a group (or groups) of healthy people. An AI
is used when a recommended dietary allowance cannot be determined.
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Adequate stimulus
A stimulus to which a particular receptor responds effectively and
that gives rise to a characteristic sensation; light and sound
waves that stimulate, respectively, visual and auditory receptors.
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Adermia
Congenital absence of skin.
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ADH
Abbreviation for antidiuretic hormone; alcohol dehydrogenase.
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Adhalin
A 50-kD glycoprotein associated with dystrophin, deficient in
patients with some forms of muscular dystrophy.
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ADHD
Abbreviation for attention-deficit/hyperactivity disorder. A
syndrome of disordered learning and disruptive behavior that is not
caused by any serious underlying physical or mental disorder and
that has several subtypes characterized primarily by symptoms of
inattentiveness or primarily by symptoms of hyperactivity and
impulsive behavior
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Adherence
1. The act or quality of sticking to something. 2. The extent to
which a patient continues an agreed-on mode of treatment without
close supervision.
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Adherence syndrome
Restriction action of an ocular muscle owing to adhesions between
the muscle and its fascial sheath.
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Adherens junction
A component of the junctional complex just beneath and supporting
the zonula occludens. The extracellular space at the adherens
junction is spanned by the extracellular aspects of cadherin
molecules, the intracellular aspects of which are supported by
actin filaments.
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Adherent leukoma
A cicatrix of the cornea to which a portion of the iris is
attached.
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Adherent placenta
A placenta that fails to separate cleanly from the uterus after
delivery of the fetus.
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Adhering junctions
Intercellular junctions, including zonulae adherentes,
hemidesmosomes, and desmosomes, that primarily serve to bind cells
together physically.
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Adhesins
Microbial surface antigens that frequently exist in the form of
filamentous projections (pili or fimbriae) and bind to specific
receptors on epithelial cell membranes; usually classified
according to their ability to induce agglutination of erythrocytes
from various species, their differential attachment to epithelial
cells of various origins, or their susceptibility to reversal of
such binding activities in the presence of mannose.
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Adhesiolysis
Severing of adhesive band(s); done by laparoscopy or laparotomy.
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Adhesion
A protein on the cell surface of some bacteria that causes cellular
aggregation. The medical term for the abnormal union of parts of
the body due to the inflammation or a band of tissue joining such
parts. Scar tissue is an example of an adhesion.
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Adhesion dyspepsia
Pain, dyspepsia, and other symptoms alleged to result from
perigastric adhesions.
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Adhesion molecule L1
An adhesion molecule overexpressed in carcinomas of uterine and
ovarian origin.
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Adhesion molecules
Molecules that are involved in T helper-accessory cell, T helper-B
cell, and T cytotoxic-target cell interactions; extracellular
matrix proteins that attract leukocytes from the circulation.
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Adhesion phenomenon
A phenomenon manifested by the adherence of
antigen-antibody-complement complex to "indicator cells"
(microorganisms, platelets, leukocytes, or erythrocytes), the
reaction being sensitive and specific for the antigen and antibody
in the complex.
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Adhesion test
The diagnostic application of the immune adhesion phenomenon.
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Adhesiotomy
Surgical section or lysis of adhesions.
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Adhesive
1. Relating to, or having the characteristics of, an adhesion. 2.
Any material that adheres to a surface or causes adherence between
surfaces.
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Adhesive absorbent dressing
A sterile individual dressing consisting of a plain absorbent
compress affixed to a film of fabric coated with a
pressure-sensitive adhesive.
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Adhesive arachnoiditis
Thickening of the leptomeninges, sometimes with obliteration of the
subarachnoid space; commonly related to acute or chronic
leptomeningitis of bacterial or chemical origin.
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Adhesive atelectasis
Alveolar collapse in the presence of patent airways, especially
when surfactant is inactivated or absent, particularly in
respiratory distress syndrome of the newborn, acute radiation
pneumonitis, or viral pneumonia.
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Adhesive bandage
Dressing of plain absorbent gauze affixed to plastic or fabric
coated with a pressure-sensitive adhesive.
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Adhesive capsulitis
Also called frozen shoulder. A condition that results in a loss of
movement and pain at the shoulder joint.
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Adhesive dentistry
Use of adhesive resins to restore lost tooth structure or retain
dental restorations.
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Adhesive inflammation
Inflammation in which the amount of fibrin in the exudate is
sufficient to result in a slight or moderate degree of adherence of
adjacent tissues, as in healing by first intention.
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Adhesive otitis
Inflammation of the middle ear caused by prolonged eustachian tube
dysfunction resulting in permanent retraction of the eardrum and
obliteration of the middle ear space.
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Adhesive pericarditis
Pericarditis with adhesions between the two pericardial layers,
between the pericardium and heart, or between the pericardium and
neighboring structures.
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Adhesive peritonitis
A form of peritonitis in which a fibrinous exudate occurs, matting
together the intestines and various other organs.
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Adhesive phlebitis
A form of phlebitis in which the walls adhere, leading to
obliteration of the vessel.
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Adhesive tape
Fabric or film evenly coated on one side with a pressure-sensitive
adhesive mixture.
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Adhesive vaginitis
Inflammation of vaginal mucosa with adhesions of the vaginal walls
to each other.
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Adhib.
Abbreviation for L. adhibendus, to be administered.
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Adiabatic
Referring to a thermodynamic process in which no gain or loss of
heat occurs between the system and its surroundings.
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Adiadochokinesis
Inability to perform rapid alternating movements. A clinical
manifestation of cerebellar dysfunction.
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Adiaphoria
Failure to respond to stimulation after a series of previously
applied stimuli.
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Adiaspiromycosis
A rare pulmonary mycosis of humans, rodents, and other animals that
dig in soil or are aquatic, caused by the fungus Emmonsia parva
var. crescens.
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Adiaspore
A fungus spore that, when growing in the lungs of an animal or
incubated in vitro at elevated temperatures, increases greatly in
size without eventual reproduction or replication.
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Adiastole
Absence or imperceptibility of the diastolic movement of the heart;
diastolic ventricular functional abnormality.
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Adiathermancy
Impermeability to heat.
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Adie syndrome
An idiopathic postganglionic denervation of the parasympathetically
innervated intraocular muscles, usually complicated by signs of
aberrant regeneration of these nerves: a weak light reaction with
segmental palsy of iris sphincter, a strong, slow near response.
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Adiemorrhysis
Arrest of the capillary circulation.
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Adi-mantra
Literally, primal or original mantra. Refers to the mantra used to
time-in before doing Kundalini Yoga.
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Adinida
A suborder of dinoflagellates, in which the flagella are free and
do not lie in furrows.
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Adip-
Fat, fatty. Corresponds to G. lip-, lipo-.
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Adipocellular
Relating to both fatty and cellular tissues, or to connective
tissue with many fat cells.
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Adipoceratous
Relating to adipocere.
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Adipocere
A fatty substance of waxy consistency derived from dead animal
tissues (a corpse) that forms in anerobic conditions.
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Adipokine
Cytokine (tumor necrosis factor-α, interleukin-6) produced by
adipose tissue and acting locally in an autocrine-paracrine fashion
or systemically as a hormone.
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Adipokinetic
Denoting a substance or factor that causes mobilization of stored
lipids.
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Adipokinin
An anterior pituitary hormone that causes mobilization of fat from
adipose tissue.
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Adipometer
An instrument for determining the thickness of the skin.
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Adiponecrosis
Rarely used term referring to necrosis of fat, as in hemorrhagic
pancreatitis.
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Adiponectin
Protein hormone produced and secreted by adipocytes into the
systemic blood circulation; causes sensitivity of peripheral
tissues to insulin.
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Adiposalgia
Condition in which painful areas of subcutaneous fat develop.
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Adipose
Adipose tissue is an anatomical term for loose connective tissue
composed of adipocytes. Its main role is to store energy in the
form of fat, although it also cushions and insulates the body. It
has an important endocrine function in producing
recently-discovered hormones such as leptin, resistin, and TNFα.
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Adipose fossae
Subcutaneous spaces containing accumulations of fat in the breast.
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Adipose infiltration
Growth of normal adult fat cells in sites where they are not
usually present.
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Adipose tissue
A form of connective tissue consisting chiefly of fat cells
surrounded by reticular fibers and arranged in lobular groups or
along the course of one of the smaller blood vessels.
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Adiposis
Excessive local or general accumulation of fat in the body.
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Adiposis cerebralis
Obesity resulting from intracranial disease, most commonly of the
hypothalamus, resulting in hyperphagia.
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Adiposis dolorosa
A condition characterized by a deposit of symmetric nodular or
pendulous masses of fat in various regions of the body, with
discomfort or pain.
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Adiposis tuberosa simplex
A condition resembling adiposis dolorosa, in which the fat occurs
in small, nodular masses, which are sensitive to touch and may be
spontaneously painful, on the abdomen or extremities.
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Adiposis universalis
Excessive deposition of fat throughout the body, including the
viscera.
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Adipositas
Synonym for obesity.
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Adiposity
Excessive accumulation of lipids in a site or organ.
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Adiposity rebound
Period of increasing body mass index after the early childhood
nadir, usually about 6 years old.
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Adiposogenital dystrophy
A disorder characterized primarily by obesity and hypogonadotrophic
hypogonadism in adolescent boys; dwarfism is rare, and when present
is thought to reflect hypothyroidism. Vision loss, behavioral
abnormalities, and diabetes insipidus may occur. Fröhlich syndrome
is a common synonym for this disorder.
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Adipsia
Absence of thirst or the lack of desire to drink.
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Aditus to mastoid antrum
The orifice leading from the epitympanic recess to the mastoid
antrum.
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Adjacent angle
An angle with a line in common with another angle.
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Adjunct
1. Assisting in the prevention, amelioration, or cure of a disease.
2. In cancer therapy, a drug or substance used in addition to the
primary therapy.
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Adjustable articulator
1. An articulator that may be adjusted to permit movement of the
casts into recorded eccentric relationships. 2. An articulator
capable of adjustment to more than one eccentric position.
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Adjustable axis face-bow
A face-bow the caliper ends of which can be adjusted to permit
location of the axis of rotation of the mandible.
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Adjustable occlusal pivot
An occlusal pivot that may be adjusted vertically by means of a
screw or by other means.
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Adjustment
1. In dentistry, any modification made to a fixed or removable
prosthesis during or after its insertion to perfect its adaptation
and function. 2. A summarizing procedure for a statistical measure
in which the effects of differences in composition of the
populations being compared have been minimized by statistical
methods.
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Adjustment disorder
An abnormal and excessive reaction to a life stressor, such as
starting school, getting divorced, or grief.
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Adjustment reaction disorder
An excessive reaction to a stressful event or situation. This
reaction seriously impairs social and occupational functioning. The
disorder is different from other mental illnesses in that its
duration is relatively brief. Symptoms appear within three months
of the stressor, and generally resolve within six months after the
stressor has ended.
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Adjuvant
A substance that enhances the effect of the medicinal agent or
increases the antigenicity of a cancer cell. That which assists,
especially a drug added to a prescription to hasten or increase the
action of the principal ingredient. A substance added to a drug
that affects the action of the active ingredient in a predictable
way.
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Adjuvant chemotherapy
Chemotherapy given in addition to surgical therapy, in order to
reduce the risk of local or systemic relapse.
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Adjuvant therapy
Treatment given in addition to the primary treatment.
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Adjuvant vaccine
A vaccine that contains an adjuvant; the antigen (immunogen) is
included in a water-in-oil emulsion (Freund incomplete type
adjuvant), or is adsorbed onto an inorganic gel (alum, aluminum
hydroxide or phosphate), or mixed with another material to prevent
rapid elimination by the host.
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Adler test
Obsolete test to measure stool blood; use with benzidine.
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Adlerian
Relating to or described by Alfred Adler.
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ADLs
Activities of daily living. These include bathing, grooming, and
feeding onself.
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Admantinoma
1. A low-grade malignant tumor of long bones (predominantly tibia)
marked by a proliferation of nests of basaloid cells with
palisading at the periphery. 2. A rare, slow-growing but locally
aggressive tumor; its histogenesis remains controversial.
Approximately 200 cases have been reported since it was first
described in 1913. The tumor occurs almost exclusively in the long
bones; tumors in the tibia account for more than 80% of cases. The
diaphysial region is the area most commonly affected. The
histiologic features of adamantinomas have many variations that are
present not only among patients but also among different areas of
the same tumor. Metastases occur in approximately 15-20% of
patients and typically appear in the lungs and local lymph nodes.
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Admedial
Toward or near the median plane.
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Adminiculum
That which gives support to a part.
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Administrator
A person or entity managing executive duties.
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Admov.
Abbreviation for L. admove, apply.
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A-DNA
A form of DNA in which the helix is right handed and the overall
appearance is short and broad.
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Adnate
Growing fast to; born adherent; the anther is adnate when fixed by
its whole length to the filament or its prolongation.
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Adneural
1. Lying near a nerve. 2. In the direction of a nerve; said of an
electric current passing through muscular tissue toward the point
of entrance of the nerve.
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Adnexa
This Latin word (in the plural) is used in medicine in reference to
appendages. For example, in gynecology the adnexa are the
"appendages" of the uterus, namely the ovaries, Fallopian tubes,
and ligaments that hold the uterus in place.
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Adnexal
Relating to the adnexa.
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Adnexal adenoma
An adenoma arising in, or forming structures resembling, skin
appendages.
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Adnexal carcinoma
A carcinoma arising from sweat or sebaceous glands.
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Adnexal mass
A lump in tissue near the uterus, usually in the ovary or fallopian
tube. Adnexal masses include ovarian cysts, ectopic (tubal)
pregnancies, and benign (noncancerous) or malignant (cancerous)
tumors.
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Adnexectomy
1. Excision of any adnexa. 2. In gynecology, excision of the
uterine tube and and ovaries (adnexa uteri) if bilateral.
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Adnexopexy
Operation for suspension of the uterine tube and ovary; usually,
oophoropexy is accomplished without suspension of the tube.
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Ado
Symbol for adenosine.
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Adolescence
The period of life beginning with puberty and ending with completed
growth and physical maturity.
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Adolescent
1. Pertaining to adolescence. 2. A person in that stage of
development.
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Adolescent albuminuria
Functional albuminuria occurring at about the time of puberty; it
is usually cyclic or orthostatic albuminuria.
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Adolescent crisis
The emotional turmoil often accompanying adolescence.
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Adolescent medicine
The branch of medicine concerned with the treatment of youth in the
approximate age range of 13-21 years.
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AdoMet
Abbreviation for S-adenosyl-l-methionine.
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Adonis
Medicinal herb obtained from Adonis vernalis (family
Ranunculaceae), grown in eastern Europe and used there in the
treatment of congestive heart failure. Contains strophanthidin and
related cardiotonic glycosides.
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Adoptive immunotherapy
Passive transfer of immunity from an immune donor through
inoculation of sensitized lymphocytes, or antibodies in serum or
gamma globulin.
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ADP
Abbreviation for adenosine diphosphate. An important compound for
the storage of energy in cells, as well as the synthesis
(formation) of nucleic acids.
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ADP ribosylation
Covalent attachment of an ADP-ribosyl moiety to a macromolecule,
the action of diphtheria toxin.
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ADR
Abbreviation for adverse drug reaction.
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Adrenal adrogen-stimulating hormone
A putative pituitary hormone that may be responsible for increased
secretion of adrenal androgens during puberty.
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Adrenal androgen
Any androgenic hormone of adrenocortical origin;
dehydroepiandrosterone (and its sulfate), androstenedione,
11β-hydroxyandrostenedione.
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Adrenal apoplexy
Hemorrhage into the suprarenal glands or thrombosis of the
suprarenal veins, followed by acute adrenal insufficiency,
occurring in the Waterhouse-Friderichsen syndrome.
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Adrenal cortical carcinoma
A carcinoma arising in the adrenal cortex that may cause virilism
or Cushing syndrome.
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Adrenal cortical syndrome
An inexact (and obsolete) term that has been applied to Cushing
syndrome, Addison disease, or the adrenogenital syndrome.
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Adrenal glands
A pair of small glands, located above the kidneys, consisting of an
outer cortex and inner medulla. The adrenal cortex secretes
cortisone-related hormones and the adrenal medulla secretes
epinephrine (adrenaline) and norepinephrine (noradrenaline.)
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Adrenal hermaphroditism
Altered appearance of the genitalia resulting from disorders of
adrenocortical function, most often female virilization; not an
example of true hermaphroditism.
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Adrenal hypertension
Hypertension resulting from an adrenal medullary pheochromocytoma
or from hyperactivity or functioning tumor of the adrenal cortex.
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Adrenal suppression
The most common cause of adrenal insufficiency, usually iatrogenic,
as a result of long-term use of glucocorticoids, particularly
critical in stress situations.
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Adrenal virilism
Virilism produced by excessive or abnormal secretory patterns of
adrenocortical steroids.
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Adrenal weight factor
A postulated substance of adenohypophysial origin responsible for
maintenance of the weight of the adrenal cortex.
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Adrenalectomy
Removal of one or more of the adrenal glands.
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Adrenaline
A substance produced by the medulla (inside) of the adrenal gland,
adrenaline (the official name in the British Pharmacopoeia) is
synonymous with epinephrine. Technically speaking, adrenaline is a
sympathomimetic catcholamine. It causes quickening of the
heartbeat, strengthens the force of the heart's contraction, opens
up the bronchioles in the lungs, and has numerous other effects.
The secretion of adrenaline by the adrenal is part of the
"fight-or-flight" reaction that humans have in response to being
frightened.
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Adrenalone
Precursor of epinephrine in some manufacturing processes; formerly,
a topical adrenergic agent in ophthalmology.
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adrenalopathy
Any pathologic condition of the suprarenal glands.
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Adrenarche
1. Growth of axillary and pubic hair induced by hyperactivity of
the suprarenal cortex in early puberty. 2. Physiologic change at
puberty caused by adrenocortical secretion of androgenic hormones
or their precursors.
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Adrenergic
1. Activated by or capable of releasing epinephrine or an
epinephrinelike substance, especially in the sympathetic nervous
system: adrenergic nerve fibers. 2. Having physiological effects
similar to those of epinephrine: an adrenergic drug. 3. Relating to
nerve endings that use norephinephrine as primary
neurotransmitters.
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Adrenergic blockade
Selective inhibition by a drug of the responses of effector cells
to adrenergic sympathetic nerve impulses (sympatholytic) and to
epinephrine and related amines (adrenolytic).
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Adrenergic blocking agent
A compound that selectively blocks or inhibits responses to
sympathetic adrenergic nerve activity (sympatholytic agent) and to
epinephrine, norepinephrine, and other adrenergic amines
(adrenolytic agent); two distinct classes exist, α- and
β-adrenergic receptor blocking agents.
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Adrenergic fibers
Nerve fiber's that transmit nervous impulses to other nerve cells
(or smooth muscle or gland cells) by the medium of the
adrenalinelike transmitter substance norepinephrine
(noradrenaline).
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Adrenergic neuronal blocking agent
A drug that prevents the release of norepinephrine from sympathetic
nerve terminals; it does not inhibit the responses of the
adrenergic receptors to circulating epinephrine, norepinephrine,
and other adrenergic amines.
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Adrenergic neurotransmitter
A neurotransmitter formed in sympathetic postganglionic synapses
(norepinephrine).
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Adrenergic receptors
Reactive components of effector tissues, most of which are
innervated by adrenergic postganglionic fibers of the sympathetic
nervous system. Such receptors can be activated by norepinephrine
and/or epinephrine and by various adrenergic drugs; receptor
activation results in a change in effector tissue function, such as
contraction of arteriolar muscles or relaxation of bronchial
muscles; adrenergic receptors are divided into α-receptors and
β-receptors, on the basis of their response to various adrenergic
activating and blocking agents.
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Adrenic
Relating to the suprarenal gland.
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Adreno-
Relating to the suprarenal gland.
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Adrenoceptive
Referring to chemical sites in effectors with which the adrenergic
mediator unites.
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Adrenocortical
Having to do with or made by the outer layer of the adrenal gland,
which produces steroid hormones. There is an adrenal gland on top
of each kidney.
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Adrenocortical adenoma
A benign tumor of adrenal cortical cells; small unencapuslated
nodules of adrenal cortex are probably localized areas of
hyperplasia rather than adenomas; true adenomas are rare and may be
symptomless or associated with Cushing syndrome or primary
aldosteronism.
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Adrenocortical hormones
Hormones secreted by the human adrenal cortex, cortisol,
aldosterone, and corticosterone.
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Adrenocortical insufficiency
Loss, to varying degrees, of adrenocortical function.
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Adrenocorticomimetic
Mimicking or producing effects similar to adrenocortical function.
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Adrenocorticotropic
Stimulating growth of the suprarenal cortex or secretion of its
hormones.
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Adrenocorticotropic hormone
The hormone of the anterior lobe of the hypophysis that governs the
nutrition and growth of the adrenal cortex, stimulates it to
functional activity, and shows extraadrenal adipokinetic activity;
it is a polypeptide containing 39 amino acids, but exact structure
varies from one species to another; sometimes prefixed by α to
distinguish it from β-corticotropin. The first 13 amino acids at
the N-terminal region are identical to α-melanotropin.
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Adrenocorticotropic peptide
A peptide with ACTH activity, isolated from pituitary extracts.
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Adrenocorticotropin releasing factor
Hormone produced by the hypothalamus that causes the pituitary to
secrete adrenocorticotropic hormone.
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Adrenogenic
Of suprarenal origin.
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Adrenogenital syndrome
Generic designation for a group of disorders caused by congenital
adrenocortical hyperplasia characterized by masculinization of
women, feminization of men, sexual ambiguity or precocious sexual
development of children; representative of excessive or abnormal
secretory patterns of adrenocortical steroids, especially those
with androgenic or estrogenic effects.
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Adrenoleukodystrophy
1. A rare inherited genetic disorder which results in degeneration
of the fatty insulation covering on nerve fibers in the brain
(myelin sheath) and the adrenal gland. 2. Any of several closely
related inheritable disorders that involve the breakdown of certain
fats. These disorders affect the adrenal glands, nervous system,
and testes.
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Adrenolytic
Denoting antagonism to or inhibition or blockade of the action of
epinephrine, norepinephrine, and related sympathomimetics.
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Adrenomedullary hormones
Hormones produced by the adrenal medulla, particularly the
catecholamines epinephrine and norepinephrine.
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Adrenomedullin
A peptide produced by vascular endothelium and the adrenal medulla;
in experimental animal studies, it exerts a long-lasting
hypotensive effect associated with reduced vascular resistance and
inhibition of aldosterone secretion from the zona glomerulosa of
the adrenal cortex.
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Adrenomegaly
Enlargement of one or both suprarenal glands.
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Adrenomimetic
Having an action similar to that of the compounds epinephrine and
norepinephrine, which are liberated from the suprarenal medulla and
adrenergic nerves; term proposed to replace the less accurate term,
sympathomimetic.
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Adrenomyeloneuropathy
A disorder of men, consisting of long-standing adrenal
insufficiency, hypogonadism, progressive myelopathy, peripheral
neuropathy, and sphincter disturbances; considered a variant of
adrenoleukodystrophy.
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Adrenopause
Decrease in function of the androgen-secreting zone of the adrenal
glands with increasing age, analogous to menopause.
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Adrenoprival
Rarely used term indicating a loss of suprarenal function, as a
result of either disease or surgical excision.
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Adrenoreactive
Responding to the catecholamines.
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Adrenosterone
An androgen isolated from the suprarenal cortex with weak
androgenic effect.
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Adrenotoxin
A substance toxic to the suprarenal glands.
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Adriamycin
An anticancer drug that belongs to the family of drugs called
antitumor antibiotics. It is an anthracycline. Also called
doxorubicin.
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Adson forceps
A small thumb forceps with two teeth on one tip and one tooth on
the other.
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Adson test
A test for thoracic outlet syndrome; the patient is seated, with
head extended and turned to the side of the lesion; with deep
inspiration there is a diminution or total loss of radial pulse on
the affected side. Not all patients with a positive result to Adson
test have thoracic outlet syndrome.
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Adsorb
To take up by adsorption.
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Adsorbate
Any adsorbed substance.
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Adsorbent
1. A substance that adsorbs, a solid substance endowed with the
property of attaching other substances to its surface without any
covalent bonding, activated charcoal. 2. An antigen or antibody
used in immune adsorption.
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Adsorption
The property of a solid substance of attracting and holding to its
surface a gas, liquid, or a substance in solution or in suspension,
condensation of a gas onto a surface.
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Adsorption chromatography
Chromatography in which separation of substances is achieved by the
difference in degree of adsorption of the compounds to a stationary
phase.
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Adsorption theory of narcosis
That a drug becomes concentrated at the surface of the cell as a
result of adsorption, and thus alters permeability and metabolism.
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Adsternal
Near or on the sternum.
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Adterminal
In a direction toward the nerve endings, muscular insertions, or
the extremity of any structure.
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Adult
1. Fully grown and physically mature. 2. A fully grown and mature
individual.
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Adult foveomacular retinal dystrophy
An autosomal dominant disorder presenting in the fifth decade with
a mild decrease in vision and a subfoveal round yellow lesion with
a central hyperpigmented spot.
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Adult hypophosphatasia
An autosomal dominant skeletal disorder with early loss of teeth,
bowing of limbs diagnosed as rickets, and beaten-copper appearance
on skull radiographs. It is caused by mutation in the gene ALPL
encoding tissue-nonspecific alkaline phosphatase on 1p.
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Adult lactase deficiency
Onset of lactase deficiency, with resulting milk intolerance and
malabsorption, in adulthood. Inherited forms may not be manifest
until adulthood; any process that damages the intestinal lining
cells can cause lactase deficiency in adults.
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Adult macular degeneration
Deterioration of the macula in the eye.
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Adult onset diabetes
A disorder in which the body does not make enough insulin or does
not properly use the insulin it produces.
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Adult polycystic disease
An inherited disease that causes many cysts to form in the kidneys.
Cysts, which are sacs filled with fluid, grow in both kidneys
causing them to become enlarged. The number of cysts can range from
a few to a great number.
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Adult respiratory distress syndrome
ARDS. A life-threatening lung condition. It is a form of breathing
failure that can occur in very ill or severely injured people. It
is not a specific disease. It starts with swelling of tissue in the
lungs and buildup of fluid in the tiny air sacs that transfer
oxygen to the bloodstream. This leads to low blood oxygen levels.
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Adult Still's disease
An illness with fever, rash, and joint pain. It may lead to chronic
arthritis.
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Adult T-cell lymphoma
An acute or subacute disease associated with a human T-cell virus,
with lymphadenopathy, hepatosplenomegaly, skin lesions, peripheral
blood involvement, and hypercalcemia.
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Adulterant
An unintended ingredient or unacceptable additive or replacement in
a specified medicinal product (herb, supplement, or prescription
drug.)
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Adulteration
Addition of any substance to a product with the intent to defraud.
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Adultomorphism
Interpretation of children's behavior in adult terms.
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Adult-onset diabetes
Former designation for type 2 diabetes.
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Adult-onset Still's disease
Although Still's disease was first described in children, it is
known to begin in adults.
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Adv.
Abbreviation for L. adversum, against.
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Advance
To move forward.
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Advance directives
Advance directives preserve the person's right to accept or reject
a course of medical treatment even after that person becomes
mentally or physically incapacitated to the point of being unable
to communicate those wishes. There are two basic types of advance
directives: (1) a living will, in which the person outlines
specific treatment guidelines that are to be followed by health
care providers; (2) a health care proxy (also called a power of
attorney for healthcare decision making) in which the person
designates a trusted individual to make medical decisions in the
event that he or she becomes too incapacitated to make such
decisions. Advance directive requirements vary greatly from one
jurisdiction to another and should therefore be drawn up in
consultation with an attorney who is familiar with the laws of the
particular jurisdiction.
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Advance medical directives
Advance directives preserve the person's right to accept or reject
a course of medical treatment even after that person becomes
mentally or physically incapacitated to the point of being unable
to communicate those wishes. There are two basic types of advance
directives: (1) a living will, in which the person outlines
specific treatment guidelines that are to be followed by health
care providers; (2) a health care proxy (also called a power of
attorney for healthcare decision making) in which the person
designates a trusted individual to make medical decisions in the
event that he or she becomes too incapacitated to make such
decisions. Advance directive requirements vary greatly from one
jurisdiction to another and should therefore be drawn up in
consultation with an attorney who is familiar with the laws of the
particular jurisdiction.
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Advanced dowsing
Radiesthesia without an "instrument" (e.g., a pendulum.)
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Advanced Energy Healing
Alleged "journey" into "higher realms" of understanding whereby one
supposedly connects with one's "divine self." Taught by Robert T.
Jaffe, M.D., D.D., the method encompasses aura analysis, the
Awareness Release Technique, clairvoyant diagnosis,
"magnetic/radiatory healing," "soul merging," and "third eye
awakening." Also called Robert Jaffe Advanced Energy Healing.
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Advanced glycation end-products
Glycation adducts of sugars and proteins involved in the collagen
cross-linking occurring with aging.
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Advanced Ingham Method™
Comprehensive form of the Original Ingham Method.
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Advanced Kum Nye
Apparently, an alleged means of promoting confidence, power, and
endurance through stimulation and transformation of bodily and
mental "energies."
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Advanced life support
Definitive emergency medical care that may include defibrillation,
airway management, and use of drugs and medications.
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Advanced multiple-beam equalization radiography
A variant of scanning equalization radiography using several x-ray
beams.
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Advanced pranic healing
Subject of a "serious reference work" of the same name, written by
chemical engineer and "Grandmaster Pranic Healer" Choa Kok Sui. The
method includes chakral pranic healing and color pranic healing.
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Advanced Rolfing
Form of Rolfing purportedly geared to clients who have undergone
the basic Rolfing series of ten sessions.
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Advancement flap
A section of skin, usually without discrete sides and a base, moved
forward perpendicular to its leading edge into a defect.
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Adventitia
The outermost connective tissue covering of any organ, vessel, or
other structure (or part thereof) not covered by a serous coat
(visceral peritoneum); instead, the covering is properly derived
from without (from the surrounding connective tissue) and does not
form an integral part of such organ or structure. Terminologia
Anatomica lists adventitia (tunica adventitia) of the following
organs: blood vessels, ductus deferens, esophagus, renal pelvis,
seminal glands, and ureters.
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Adventitial
Relating to the outer coat or adventitia of a blood vessel or other
structure.
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Adventitial neuritis
Inflammation of the sheath of a nerve.
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Adventitious
1. Arising from an external source or occurring in an unusual place
or manner. 2. Occurring accidentally.
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Adventitious albuminuria
Albuminuria resulting from the presence of blood escaping somewhere
in the urinary tract, of chyle, or of some other albuminous fluid,
not caused by filtration of albumin from the blood through the
kidneys.
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Adventitious breath sounds
Sounds heard on auscultation of abnormal lungs.
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Adventitious bursa
A bursa-like cyst formed between two parts as a result of friction.
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Adverse drug reaction
A response to a drug that is noxious, unintended, and occurs at
doses normally used in humans for prophylaxis, diagnosis, or
therapy of disease or for the modification of physiologic function.
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Adverse effect
1. An unwanted side effect of treatment. 2. Unintended or harmful
effects caused by exposure to a chemical; also known as side
effects.
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Adverse event
In pharmacology, an adverse event is any unexpected or dangerous
reaction to a drug.
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Adverse reaction
Any undesirable or unwanted consequence of a preventive,
diagnostic, or therapeutic procedure or regimen.
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Adversive movement
A rotation of the eyes, head, or trunk about the long axis of the
body.
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Adynamia
Loss of strength or vigor (weakness), usually because of disease.
Lack of physical or emotional drive.
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Adynamia episodica hereditaria
Hyperkalemic periodic paralysis, without myotonia.
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Adynamic
Relating to adynamia.
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Adynamic ileus
A "non-mechanical" bowel obstruction, which results when
peristalsis stops. Peristalsis is the wavelike contractions that
help move food through the colon.
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A-E amputation
Acronym for above-the-elbow amputation.
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Aeby plane
In craniometry, a plane perpendicular to the median plane of the
cranium, cutting the nasion and the basion.
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AECB
Abbreviation for acute exacerbation of chronic bronchitis.
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AED
Abbreviation for automated external defibrillator.
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Aedes
A widespread genus of small mosquitoes frequently found in tropic
and subtropic regions.
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Aedes aegypti
The mosquito responsible for yellow fever, a species that is also
the vector of the pathogen of dengue; characterized by white
lyre-shaped markings on the thorax.
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Aedes albopictus
Mosquito species widespread in Pacific basin; recently seen in the
Americas; an important vector of dengue fever and likely also of
West Nile virus.
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Aedes atlanticus
Mosquitoes in the family Culicidae known to transmit viruses that
cause dengue, yellow fever, and encephalitis.
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Aedes caballus
Mosquito species that is an important vector of Rift Valley fever
in Africa.
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Aedes dorsalis
Mosquito species that is a secondary or suspected vector of western
equine encephalitis.
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Aedes leucocelaenus
Mosquito species that transmits yellow fever in South America.
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Aedes melanimon
Mosquito species that is a vector of western equine encephalitis
and California group encephalitis.
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Aedes mitchellae
Mosquito species that is a secondary or suspected vector of eastern
equine encephalitis.
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Aedes nigromaculis
Mosquito species that is a secondary or suspected vector of western
equine encephalitis and California group encephalitis.
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Aedes polynesiensis
Mosquito species that is an important vector of filariasis and
dengue in Polynesia.
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Aedes sollicitans
A common salt-marsh mosquito species and vector of eastern equine
encephalomyelitis on the Atlantic and Gulf coasts of the United
States.
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Aedes taeniorhynchus
Mosquito species that is a vector of Venezuelan equine encephalitis
and a secondary or suspected vector of California group
encephalitis.
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Aedes triseriatus
Mosquito species that is a vector of California group encephalitis.
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Aedes trivittatus
Mosquito species that is a vector of California group encephalitis.
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Aedes variegatus
Mosquito species that is a vector of filarial parasites in the
Pacific Islands.
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Aedes vexans
Mosquito species that is a vector of California group encephalitis
and a secondary or suspected vector of eastern equine encephalitis.
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Aegyptiacus
In botany, of Egypt.
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Aelurostrongylus
A common genus of lungworm in cats; land snails and slugs serve as
intermediate hosts and snail-eating animals can serve as transport
hosts.
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Aequorin
A luminescent protein isolated from the jellyfish Aequorea that
emits blue light in the presence of even minute amounts of calcium
ion; injected intracellularly, it is used to measure free calcium
ion transients within cells.
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Aer-
The air, a gas; aerial, gassy.
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Aerate
1. To supply (blood) with oxygen. 2. To expose to the circulation
of air for purification. 3. To supply or charge (liquid) with a
gas, especially carbon dioxide.
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Aeration
The state of containing air, or the process of filling with air;
inflation; in radiology, specifically, within the lung.
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Aerendocardia
Presence of undissolved air in the blood within the heart.
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Aerial mycelium
The portion of mycelium that grows upward or outward from the
surface of the substrate, and from which propagative spores develop
in or on characteristic structures that are distinctive for various
generic groups.
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Aerobe
1. An organism that can live and grow in the presence of oxygen. 2.
An organism that can use oxygen as a final electron acceptor in a
respiratory chain.
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Aerobic
Pertaining to processes that require oxygen. For example, aerobic
exercises are those in which the body uses more oxygen than it
would in other forms of exercise.
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Aerobic dehydrogenase
An enzyme (usually a metalloflavoenzyme) catalyzing the transfer of
hydrogen from some metabolite to oxygen, forming hydrogen peroxide
in the process; xanthine oxidase and others in several
sub-subclasses.
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Aerobic metabolism
A chemical process in which oxygen is used to make energy from
carbohydrates (sugars.) Also known as aerobic respiration,
oxidative metabolism, or cell respiration.
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Aerobic respiration
A chemical process in which oxygen is used to make energy from
carbohydrates (sugars.) Also known as oxidative metabolism, cell
respiration, or aerobic metabolism.
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Aerobiology
The study of atmospheric constituents, living and nonliving, of
biologic significance, airborne spores, pathogenic bacteria,
allergenic substances, pollutants.
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Aerobioscope
An apparatus for determining the bacterial content of the air.
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Aerobiosis
Existence in an atmosphere containing oxygen.
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Aerobiotic
Relating to aerobiosis.
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Aerocele
Distention of a small natural cavity with gas.
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Aerococcus
A genus of aerobic gram-positive cocci occurring as airborne
saprophytes; they produce α-hemolysis on blood agar and grow in the
presence of 40% bile. Aerococcus viridans, the type species, is
commonly recovered as part of the normal skin flora; it has low
pathogenicity but has been reported as a rare cause of
endocarditis.
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Aerococcus urinae
A species that resembles A. viridans but that is bile-esculin
negative.
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Aerocolpos
Obsolete term for distention of the vagina with gas.
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Aerodigestive tract
The combined organs and tissues of the respiratory tract and the
upper part of the digestive tract (including the lips, mouth,
tongue, nose, throat, vocal cords, and part of the esophagus and
windpipe.)
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Aerodontalgia
Dental pain caused by either increased or reduced atmospheric
pressure.
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Aerodontia
The science of the effect of either increased or reduced
atmospheric pressure on the teeth.
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Aerodynamic size
In aerosols, the particle size with unit density that best
represents the aerodynamic behavior of a particle.
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Aerodynamic theory
Generally accepted theory that the vibration of the vocal folds in
phonation is produced by the flow of exhaled air past lightly
approximated vocal folds; opposed to the now untenable concept that
vocal fold motion in phonation results from contraction of the
intrinsic muscles of the larynx at the frequency of the vocal fold
vibration.
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Aerodynamics
The study of air and other gases in motion, the forces that set
them in motion, and the results of such motion.
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Aerogastria
Distention of the stomach by gas.
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Aerogen
A gas-forming microorganism.
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Aerogenesis
Production of gas, as by a microorganism.
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Aerogenic
Gas-forming.
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Aerogenic tuberculosis
Infection with the Mycobacterium tuberculosis spread by inhalation
of infected droplets.
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Aeromonad
A vernacular term used to refer to any member of the genus
Aeromonas.
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Aeromonas
A genus of gram-negative, oxidase-positive, aerobic, facultatively
anaerobic bacteria (family Vibrionaceae) containing rod-shaped to
coccoid cells; motile cells ordinarily possess a single, polar
flagellum; some species are nonmotile. The metabolism of these
organisms is both respiratory and fermentative; nutritional
requirements are not stringent. These bacteria are found in water
and sewage; some are pathogenic to freshwater and marine animals,
and to humans. Effects in humans include cellulitis; wound
infections; acute diarrhea (especially caused by Aeromonas sobria);
septicemia; urinary tract infection; hepatobiliary, meningeal, and
auricular infections; and endocarditis. The type species is
Aeromonas hydrophila.
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Aeromonas hydrophila
A bacterial species that causes cellulitis, wound infections, acute
diarrhea (waterborne and shellfish associated), septicemia, and
urinary tract infections in humans. Also causes red leg disease in
frogs.
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Aeropause
An upper region of the atmosphere, between the stratosphere and
outer space, in which gas particles are so sparse as to provide
almost no support for human physiologic requirements or for
vehicles that require air to burn fuel.
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Aerophagia
The word "phage" in Greek means "to eat." Aerophagia is literally
to eat air. Aerophagia is a common cause of gas in the stomach.
Everyone swallows small amounts of air when eating or drinking.
However, rapid eating or drinking, chewing gum, smoking, or
ill-fitting dentures may cause a significant increase in swallowed
air.
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Aerophil
1. An organelle, cell, organ, or organism that has an affinity and
need for air. 2. An aerobic organism (aerobe), especially an
obligate aerobe.
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Aerophobia
Morbid dread of fresh air or of air in motion.
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Aeropiesotherapy
Treatment of disease with compressed (or rarified) air.
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Aeroplankton
An organism or a living substance carried by air, a bacterium,
pollen, or grain.
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Aerosis
Generation of gas in the tissues.
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Aerosol
A fine spray or mist. An aerosol can be administered by a nebulizer
and inhaled.
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Aerosol delivery system
A device useful for assisting in the delivery of medications by
inhalation.
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Aerosol generator
A device for producing airborne suspensions of small particles for
inhalation therapy or experimental work; a La Mer generator,
spinning disc, or vibrating reed, each of which produces a
monodisperse aerosol.
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Aerosol mask
A mask in which oxygen humidified by aerosolized saline is given to
a patient.
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Aerosolization
Dispersion in air of a liquid material or a solution in the form of
a fine mist, usually for therapeutic purposes, especially to the
respiratory passages.
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Aerosolize
In medicine, to turn a liquid drug into a fine mist that can be
inhaled.
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Aerospace medicine
A branch of medicine combining the areas of concern of both
aviation and space medicine.
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Aerotherapeutics
Treatment of disease with fresh air, air of different degrees of
pressure or rarity, or medicated air.
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Aerotonometer
An instrument for estimating the tension or pressure of a gas.
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Aesculapian
Relating to Aesculapius, the art of medicine, or a medical
practitioner.
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Aesthetic surgery
Surgery in which the principal purpose is to improve the
appearance.
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Aetiology
The study of the causes, for example, of a disease. The word comes
from the Greek "aitia", a cause and "logos", a discourse. Today in
medicine the word "aetiology" is incorrectly used as a synonym for
cause so often that it is fast becoming accepted usage, as in "the
aetiology is unknown." Aetiology is the preferred spelling in some
countries, including the United Kingdom, whereas "etiology" without
an "a" has taken over in the United States.
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AFA fixative
A combination of alcohol, formalin, and acetic acid used for the
fixation of nematodes, trematodes, and cestodes.
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AFB
1. Abbreviation for acid-fast bacillus. 2. Abbreviation for
aortofemoral bypass (vascular prosthetic surgery), the surgical
procedure or its result.
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Afebrile
Without fever, denoting apyrexia; having a normal body temperature.
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Afetal
Without relation to a fetus or intrauterine life.
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Affect
The emotional feeling, tone, and mood attached to a thought,
including its external manifestations.
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Affect displacement
A shift of feeling from the object originally arousing it to some
associated object.
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Affect display
Facial expressions, postures, and gestures indicating emotional
states.
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Affect hunger
Emotional hunger for maternal love and feelings of protection and
care implied in the mother-child relationship.
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Affect memory
The emotional element recurring whenever a significant experience
is recalled.
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Affection
1. A moderate feeling of tenderness, caring, or love. 2. An
abnormal condition of body or mind.
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Affective
Pertaining to mood, emotion, feeling, sensibility, or a mental
state.
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Affective disorders
A group of mental disorders characterized by a mood disturbance.
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Affective personality
A chronic personality disorder resulting from an enduring
disturbance of mood that shapes cognition, attitude, and identity
and thus colors the whole of the person's psychic life and
interpersonal behavior.
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Affective personality disorder
An ICD diagnosis that also includes chronic hypomanic personality,
chronic depressive personality, and cyclothymia personality.
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Affective psychosis
The presence of hallucinations and delusions along with significant
mood disorder.
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Affectomotor
Pertaining to muscular manifestations associated with affective
tone.
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Afferent
Carrying impulses toward a center, as in sensory nerves conveying a
signal to the brain; also applied to certain veins and lymphatics.
Opposite of efferent.
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Afferent fibers
Fibers that convey impulses to a ganglion or to a nerve center in
the brain or spinal cord.
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Afferent glomerular arteriole of kidney
A branch of an interlobular artery of the kidney that conveys blood
to the glomerulus.
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Afferent loop syndrome
Chronic obstruction of the duodenum and jejunum proximal to the
gastrojejunostomy performed in a Billroth II-type gastrectomy; the
distended afferent loop of jejunum and duodenum causes symptoms of
pain and fullness associated with food ingestion; weight loss is
common.
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Afferent lymphatic
A lymphatic vessel entering, or bringing lymph to, a node.
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Afferent nerve
A nerve that carries impulses toward the central nervous system.
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Afferent vessel
A vessel carrying blood toward the heart. A vein or venule.
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Affinity
One of the four healing properties of herbs in traditional Chinese
medicine. Every herb purportedly has a specific affinity for one or
more yin or yang organs.
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Affinity antibody
The strength of binding between an antibody and an antigen. This
interaction is reversible or avidity between antigen and antibody
molecules, determined by the degree of complementary fit between
the immunogenic region of the antigen and the binding site on the
immunoglobulin molecule.
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Affinity chromatography
Chromatography where the absorbent has a unique chemical affinity
for a particular component of the passing solution.
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Affinous
Pertaining to a marriage in which the partners are related, not by
consanguinity but through another marriage.
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Affirmation
Positive statement that, when spoken, purportedly retrains the
mind.
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Affusion
Pouring water on the body or any of its parts for therapeutic
purposes.
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AFH
Abbreviation for anterior facial height.
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Afibrillar
Denoting a biologic structure that does not contain fibrils.
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Afibrillar cement
Cementum which, using an electron microscope, appears as laminated,
electron-dense reticular material that sometimes overlies the
enamel of the tooth.
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Afibrinogenemia
The absence of fibrinogen in the plasma.
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Afipia
A genus of gram-negative, oxidase-positive, motile, nonfermenting
bacteria that have been placed in the class Proteobacteria.
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Aflatoxicosis
A disease caused by ingestion of aflatoxin.
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Aflatoxins
Toxins produced by a mold that grows in nuts, seeds, and legumes.
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AFO
Abbreviation for ankle-foot orthosis (a brace.)
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AFORMED
Acronym for alternating failure of response, mechanical, to
electrical depolarization.
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AFORMED phenomenon
As induced pulsus alternans progresses, a state in which
alternating heart depolarizations fail to eject any blood, thus
allowing longer diastolic filling; the subsequent beat is then able
to produce a significant ejection; at high rates the cardiac minute
volume and blood pressure may appear normal.
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AFP
Abbreviation for alpha-fetoprotein. A fetal blood protein present
abnormally in adults with some forms of cancer or in the amniotic
fluid of pregnant women but with very low levels tending to be
associated with Down syndrome in the fetus and very high levels
with neural tube defects.
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African endomyocardial fibrosis
Fibrosis of the inner layers of the myocardium, often including the
endocardium, causing diastolic restriction of the heart; indigenous
to eastern Africa.
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African hemorrhagic fever
Hemorrhagic fever associated with the morphologically similar but
antigenically distinct Marburg and Ebola viruses as well as
numerous other viruses that cause similar diseases.
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African histoplasmosis
A form of histoplasmosis caused by the fungus Histoplasma
capsulatum var. duboisii, observed only in tropical Africa;
infection is manifest as chronic granulomatous lesions in bone,
skin, and other organs.
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African holistic health
Subject of African Holistic Health, whose fourth edition was
published in 1993. The paperback's author, herbalist and massage
therapist Dr. Llaila [la-ee-la] O. Afrika, developed this ethnic
variation of naturopathy. Its purported design is to treat the
physical, mental, and spiritual causes of "dis-ease." Also known as
African holistics, African holistic science, and African medicine.
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African tapeworm
The beef tapeworm (Taenia saginata), the most common of the big
tapeworms that parasitizes people, contracted from infected raw or
rare beef. Can grow to be 12-25 feet (3.6-7.5m) long in the human
intestine.
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African tick typhus
One of the tick-borne rickettsial diseases of the eastern
hemisphere, similar to Rocky Mountain spotted fever, but less
severe, with fever, a small ulcer (tache noire) at the site of the
tick bite, swollen glands nearby (satellite lymphadenopathy), and a
red raised (maculopapular) rash. Also called fièvre boutonneuse.
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African trypanosomiasis
A serious endemic disease in tropic Africa, of two types: Gambian
or West African trypanosomiasis and Rhodesian or East African
trypanosomiasis.
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Afterbirth
The placenta and the fetal membranes that are normally expelled
from the uterus after the birth of the baby, hence, the
"afterbirth." The placenta is of course the organ that joins the
mother and fetus and permits the provision of oxygen and nutrients
to the fetus and the release of carbon dioxide and waste products
from the fetus to the mother. The only disposable human organ, the
placenta is disk-shaped and at full term measures about 7 inches
(18cm) in diameter and a bit less than 2 inches (4cm) thick. The
fetal membranes-the chorion is the outer one and the amnion is the
inner one-envelop the embryo and contain the amniotic fluid. The
word "afterbirth" entered the English language in the 16th Century.
The term has also been applied to a child born after the father's
death or last testament.
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Aftercare
1. The care and treatment of a patient after an operation,
delivery, or convalescence from an illness. 2. Following
psychiatric hospitalization, a continuing program of rehabilitation
designed to reinforce the effects of the therapy; may include
partial hospitalization, day hospital, or outpatient treatment.
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Afterchroming
Additional treatment of a tissue specimen with chromate or a metal
mordant to impart special staining properties.
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Aftercontraction
A muscular contraction persisting a noticeable time after stimulus
has ceased.
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Aftercurrent
An electrical current induced in a muscle on termination of a
constant current that has been passed through it.
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Afterdischarge
Persistance of response of muscle or neural elements after
cessation of stimulation. Myotonia is a clinical manifestation of
prolonged muscle afterdischarge.
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Aftereffect
A physical, physiologic, psychological, or emotional effect that
continues after removal of a stimulus.
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Aftergilding
The treatment of a fixed and hardened histologic specimen of
nervous tissue with gold salts.
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Afterimage
Persistence of a visual response after cessation of a stimulus.
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Afterload
1. The arrangement of a muscle so that, in shortening, it lifts a
weight from an adjustable support or otherwise does work against a
constant opposing force to which it is not exposed at rest. 2. The
load or force thus encountered in shortening.
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Afterloading radiation
Method of administering radiation that involves initial placement
of local catheters with later installation of the radiation source.
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Afterloading screw
A device for setting the length at which a contracting muscle
encounters an afterload.
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Aftermovement
Involuntary arm abduction that follows sustained isometric
contraction of the deltoid and supraspinatus muscles (usually
performed by pushing the upper extremity forcibly and against an
immovable vertical surface while standing beside it).
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After-nystagmus
Nystagmus occurring after the abrupt cessation of rotation in the
opposite direction of the rotatory nystagmus.
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Afterpains
Painful cramplike contractions of the uterus occurring after
childbirth.
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Afterpotential
The small change in electrical potential in a stimulated nerve that
follows the main, or spike, potential; it consists of an initial
negative deflection followed by a positive deflection in the
oscillograph record.
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Aftersensation
Subjective persistence of sensation after a stimulus stops.
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Aftersound
Subjective persistence of an auditory sensation after cessation of
the acoustic stimulus.
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Aftertaste
Subjective persistence of a gustatory sensation after contact with
the taste stimulus has ceased.
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Aftertouch
Subjective persistence of tactile sensation after cessation of
stimulus; a form of aftersensation.
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Afunctional occlusion
A malocclusion that does not permit normal function of the
dentition.
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Ag
1. Symbol for silver (argentum). 2. Abbreviation for antigen.
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AG337
An anticancer drug used to shrink tumors; may also enhance the
effectiveness of radiation therapy.
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Agalactia
Absence of milk in the breasts after childbirth.
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Agalactorrhea
Absence of the secretion or flow of breast milk.
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Agalactous
Relating to agalactia, or to the diminution or absence of breast
milk.
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Agamete
A protozoan organism produced by asexual multiple fission.
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Agamic
Denoting nonsexual reproduction, as by fission or budding.
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Agammaglobulinemia
1. An inherited disorder characterized by very low levels of
protective immunoglobulins, affected people develop repeated
infections. 2. Total (or nearly total) absence of the
infection-fighting proteins (immunoglobulins) belonging to the
class called gamma globulins. Can be due to certain genetic
diseases or to acquired diseases such as HIV.
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Agamofilaria
A name given to immature filarial forms, the genera of the adult
forms being undetermined.
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Agamogenetic
Indicating asexual reproduction.
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Agamomermis culicis
A species of nematode parasitic in the mosquito; a few cases have
been recorded in humans, usually larval worms found emerging from
body openings, presumably after ingestion of infected insects or
application of moist earth-bearing free-living larval stages.
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Aganglionic
Without ganglia.
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Aganglionic megacolon
A rare (affects about one in 5,000 US newborns) congenital disorder
that results in an obstruction of the bowel. This prevents normal
bowel movements. It usually occurs as an isolated finding in males,
but less frequently can be part of a syndrome.
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Aganglionosis
The state of being without ganglia; absence of ganglion cells from
the myenteric plexus as a characteristic of congenital megacolon.
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Agape Quest Program
Form of kinesiology that encompasses more than twenty "modalities,"
including acupressure and, apparently, Bach flower therapy and/or
flower essence therapy. The program allegedly "unlocks blockages."
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Agapism
Agapism professes that love (or "agape") should be the sole
ultimate value and that all other values are derived from it, or
that the sole moral imperative is to love. Theological agapism
holds that our love of God is expressed by loving our fellow
humans. As the ethics of love, agapism indicates that we should do
the most loving thing in each situation, letting love determine our
obligation rather than rules. Alternatively, given a set of rules,
agapism indicates to follow those rules that produce the most love.
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Agar
A complex polysaccharide (a sulfated galactan) derived from seaweed
(various red algae); used as a solidifying agent in culture media;
it has the valuable properties of melting at 100°C, but not of
solidifying until 49°C.
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Agaric acid
A principle obtained from agaric, formerly used as an anhidrotic
agent.
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Agaricus
A large genus of mushrooms many of which are edible and others
poisonous.
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Agaropectin
A polysaccharide found in agar preparations consisting of
d-galactose and 3,6-anhydro-l-galactose linked β1,3 glycosidically.
Some of the galactosyl units are sulfated.
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Agarose
The neutral linear polysaccharide fraction found in agar
preparations, generally composed of d-galactose and altered
3,6-anhydro-l- galactose residues; used in chromatography and
electrophoresis.
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Agartha personal life balancing program
A 35-day audiotape program created by author Meredith Lady Young.
Its purported design is to reduce stress and promote "complete
health." Each of the seven "harmonic" tapes combines sounds
reportedly "developed" to alter "energy currents" within specific
chakras. These sounds supposedly "massage" chakras and thereby
improve the flow of life force through the body.
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Agastric
Without stomach or digestive tract.
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Agastroneuria
Lessened nervous control of the stomach.
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AGC
Abbreviation for automatic gain control.
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Age
1. The period that has elapsed since birth. 2. One of the periods
into which human life is divided, distinguished by physical
evolution, equilibrium, and involution; the seven ages of humankind
are infancy, childhood, adolescence, young adulthood, middle life,
senescence, and senility. 3. To grow old; to gradually develop
changes in structure that are not due to preventable disease or
trauma and that are associated with decreased functional capacity
and an increased probability of death. 4. To artificially induce an
appearance that is characteristic of one who has lived long or of a
thing that has existed for a long time. 5. In dentistry materials
science, the treatment of a material to stabilize or strengthen it
by causing a coherent precipitate to form. A coherent precipitate
is particle formation caused by clustering of atoms of one type as
part of a lattice consisting of more than one atom type.
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Agene process
Bleaching of flour with nitrogen trichloride (prohibited in the
United States).
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Agenesis
Lack of development of something. For example, agenesis of a toe
means that a toe failed to form.
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Agenitalism
Congenital absence of genitalia.
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Agenosomia
Markedly defective formation or absence of the genitalia; usually
accompanied by protrusion of the abdominal viscera through an
incomplete abdominal wall.
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Agent
1. An active force or substance capable of producing an effect. For
agents not listed here, see the specific name. 2. In disease, a
factor such as a microorganism, chemical substance, or a form of
radiation, the presence or absence of which (as in deficiency
diseases) results in disease or in more advanced form of disease.
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Agent Orange
An herbicide and defoliant consisting of
(2,4,5-trichlorophenoxy)acetic acid, (2,4-dichlorophenoxy) acetic
acid, and dioxin, that was widely used during the Vietnam War; it
has been shown to produce residual postexposure carcinogenic and
teratogenic effects in humans.
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Agent study
In cancer prevention clinical trials, a study that tests whether
taking certain medicines, vitamins, minerals, or food supplements
can prevent cancer. Also a called chemoprevention study.
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Agent, antihypertensive
As the name suggests, a drug aimed at reducing high blood pressure
(hypertension).
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Agent, anti-infective
Something capable of acting against infection, by inhibiting the
spread of an infectious agent or by killing the infectious agent
outright.
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Agent, tocolytic
A medication that can inhibit labor, slow down, or halt the
contractions of the uterus. Tocolytic agents are widely used today
to treat premature labor and permit pregnancy to procede and so let
the fetus gain in size and maturity before being born.
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Agerasia
A youthful appearance in old age.
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Age-related macular degeneration
A common macular degeneration beginning with drusen of the macula
and pigment disruption and sometimes leading to severe loss of
central vision.
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Age-specific rate
A rate for a specified age group, in which the numerator and
denominator refer to the same age group.
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Ageusia
Loss or absence of the sense of taste. It may be: general to all
tastants (total), partial to some tastants, or specific to one or
more tastants; due to transport disorders (in access to the
interior of the taste bud) or sensorineural disorders (affecting
the gustatory sensory cells or nerves or the central gustatory
neural pathways); or hereditary or acquired.
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Agger
An eminence, projection, or shallow ridge.
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Agger nasi
An elevation on the lateral wall of the nasal cavity lying between
the atrium of the middle meatus and the olfactory sulcus; it is
formed by the mucous membrane covering the base of the ethmoidal
crest of the maxilla.
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Agglutinant
A substance that holds parts together or causes agglutination.
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Agglutinate
To accomplish, or be subjected to, agglutination.
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Agglutination
1. The process by which suspended bacteria, cells, or other
particles are caused to adhere and form into clumps; similar to
precipitation, but the particles are larger and are in suspension
rather than being in solution. 2. Adhesion of the surfaces of a
wound. 3. The process of adhering.
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Agglutinative
Causing, or able to cause, agglutination.
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Agglutinin
A substance that makes particles (such as bacteria or cells) stick
together to form a clump or a mass.
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Agglutinogen
An antigenic substance that stimulates the formation of specific
agglutinin, which can cause agglutination of cells that contain the
antigen or particles coated with the antigen.
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Agglutinogenic
Capable of causing the production of an agglutinin.
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Agglutinophilic
Readily undergoing pronounced agglutination.
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Aggravation
A temporary worsening of already existing symptoms after taking a
homeopathic remedy.
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Aggrecan
Candidate gene for otosclerosis located at 15q25 to q26.
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Aggrecanase
An enzyme found in cartilage that degrades extracellular matrix,
especially cartilage.
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Aggregate
1. To unite or come together in a mass or cluster. 2. The total of
individual units making up a mass or cluster.
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Aggregate anaphylaxis
An anaphylactic reaction initiated by the formation of
antigen-antibody complexes that activate complement.
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Aggregated
Collected together, thereby forming a cluster, clump, or mass of
individual units.
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Aggregated lymphoid nodules of appendix
Masses of lymphoid tissue in the submucous coat of the vermiform
appendix.
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Aggregated lymphoid nodules of the small intestine
Collections of many lymphoid follicles closely packed together in
the lamina propria, forming oblong elevations on the mucous
membrane of the ileum opposite the attachment of mesentary.
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Aggregation
A crowded mass of independent but similar units; a cluster.
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Aggregometer
An instrument for measuring platelet aggregation by monitoring over
time the changes in optic density of a platelet suspension treated
with aggregating agents (ADP, collagen, epinephrine).
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Aggressin
Obsolete term for a substance of microbial origin postulated to
inhibit the resistance mechanisms of the host.
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Aggressive
A quickly growing cancer.
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Aggressive angiomyxoma
Locally invasive, but nonmetastasizing tumor of genital organs in
young women.
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Aggressive infantile fibromatosis
A childhood counterpart of abdominal or extraabdominal desmoid
tumors, characterized by firm subcutaneous nodules that grow
rapidly in any part of the body that invade locally and recur but
do not metastasize.
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Aggressive lymphoma
A type of lymphoma that grows and spreads quickly, and has severe
symptoms. It is seen frequently in patients who are HIV-positive
(AIDS-related lymphoma.) Also called intermediate-grade or
high-grade lymphoma.
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Aging
1. The process of growing old, especially by failure of replacement
of cells in sufficient number to maintain full functional capacity;
particularly affects cells (neurons) incapable of mitotic division.
2. The gradual deterioration of a mature organism resulting from
time-dependent, irreversible changes in structure that are
intrinsic to the particular species, and eventually lead to
decreased ability to cope with the stresses of the environment,
thereby increasing the probability of death. 3. In the
cardiovascular system, the progressive replacement of functional
cell types by fibrous connective tissue. 4. A demographic term,
meaning an increase over time in the proportion of older people in
the population.
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Agitated depression
Depression with excitement and restlessness.
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Agitophasia
Abnormally rapid speech in which words are imperfectly spoken or
dropped out of a sentence.
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Agkistrodon rhodostoma
The Malayan pit viper.
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Aglomerular
Having no glomeruli; said especially of a kidney in which the
glomeruli have been destroyed, or kidneys of certain fish toad fish
that possess tubules but no glomeruli.
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Aglossia
Congenital absence of the tongue.
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Aglossia-adactylia syndrome
Congenital absence or hypoplasia of the tongue, associated with
absence of the digits.
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Aglossostomia
Congenital absence of the tongue, with a malformed (usually closed)
mouth.
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Aglucon
The portion of a glucoside other than the glucose.
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Aglutition
Inability to swallow.
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Aglycone
The non-carbohydrate portion of a glycoside.
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Aglycosuria
Absence of carbohydrate in the urine.
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Aglycosuric
Relating to aglycosuria.
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Agmen
Obsolete term for aggregation.
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Agnathia
Congenital absence of the mandible, usually accompanied by
approximation of the ears.
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Agnathous
Relating to agnathia.
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Agnatic
The ability to trace descent from a common male ancestor, via
another exclusively male ancestor.
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Agni
Digestive fire, synonymous with properly balanced cell metabolism
in Western medicine.
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Agni dhatu therapy©
"Hands-on" form of spiritual healing that purportedly enables the
conscious to experience the "Super-Conscious" by lulling and
healing the subconscious. Its theory posits "energies of bliss,"
"energies of joy," and "Psychic Energy Channels." Agni Dhatu
Therapy includes "OMEGA Pattern Clearing work." Practitioner Cherry
N. Manning has defined "agni dhatu" as "experiencing the
limitlessness of your inner fires."
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Agnogenic myeloid metaplasia
A progressive, chronic disease in which the bone marrow is replaced
by fibrous tissue and blood is made in organs such as the liver and
the spleen, instead of in the bone marrow. This disease is marked
by an enlarged spleen and progressive anemia. Also called chronic
idiopathic myelofibrosis, primary myelofibrosis, myelosclerosis
with myeloid metaplasia, and idiopathic myelofibrosis.
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Agnosia
Impairment of the ability to recognize, or comprehend the meaning
of, various sensory stimuli, not attributable to disorders of the
primary receptors or general intellect; agnosias are receptive
defects caused by lesions in various portions of the cerebrum.
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Agonadal
Denoting the absence of gonads.
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Agonal
A word used to describe a major negative change in a patient's
condition, usually preceding immediate death, such as a complete
cessation of breathing or a dire change in the patient's EEG or
EKG.
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Agonal clot
Intravascular thrombosis ascribed to the process of dying.
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Agonal rhythm
An idioventricular rhythm, characterized by unusually wide and
bizarre ventricular complexes, often seen in moribund patients.
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Agonal thrombus
A heart clot formed during the act of dying after prolonged heart
failure.
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Agonist
In pharmacology, a drug which binds to the receptor and stimulates
the receptor's function. Agonists often mimic the body's own
regulatory functions.
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Agony
Intense pain or anguish of body or mind.
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Agoraphobia
An abnormal fear of open or public places that is characterized by
panic, anticipatory anxiety, or avoidance of such places.
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Agoraphobic
Relating to or characteristic of agoraphobia.
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Agouti
1. The wildtype hair color banding found in mammals; including some
felidae; hairs are lighter or gray at the base and tipped with dark
or blak pigment. Multiple banding on a hair may occur. 2. A tropic
rodent.
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Agouti-related peptide
A peptide released with neuropeptide Y from specific neurons of the
arcuate nucleus. These neurons are stimulated by ghrelin and
inhibited by neuropeptide PYY and leptin. Release of agouti-related
peptide and neuropeptide Y stimulates appetite while reducing
metabolism.
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Agouti-related protein
A protein that plays a role in maintaining body weight by inducing
food intake; its nucleotide sequence or gene resides on chromosome
16 and has polymorphisms that potentially seem related to anorexia.
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Agraffe
An appliance for clamping together the edges of a wound, used in
lieu of sutures.
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Agrammatism
A form of aphasia characterized by an inability to construct a
grammatical sentence and the use of unintelligible or incorrect
words; caused by a lesion in the dominant temporal lobe.
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Agranolucytosis
Acute disease characterized by a deficit or absolute lack of
granulocytic white blood cells (neutrophils, basophils, and
eosinophils); synonym: granulocytopenia.
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Agranular endoplasmic reticulum
Endoplasmic reticulum that is lacking in ribosomes; involved in
synthesis of complex lipids and fatty acids, detoxification of
drugs, carbohydrate synthesis, and sequestering of Ca++.
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Agranulocyte
A type of white blood cell; monocytes and lymphocytes are
agranulocytes.
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Agranuloplastic
Capable of forming nongranular cells, and incapable of forming
granular cells.
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Agraphia
Inability to write properly in the absence of abnormalities of the
limb; often accompanies aphasia and alexia; caused by lesions in
various portions of the cerebrum, especially those in or near the
angular gyrus.
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Agraphic
Relating to or marked by agraphia.
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Agretope
That part of a processed antigen that binds to the major
histocompatibility complex molecule.
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AgRP
Abbreviation for agouti-related protein.
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Ague
An acute fever or fit of alternating chills and heat.
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AGUS
Acronym for atypical glandular cells of undetermined significance,
under cell.
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Agyiophobia
A form of agoraphobia characterized by a morbid fear of being in
the street.
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Agyria
Congenital lack or underdevelopment of the convolutional pattern of
the cerebral cortex.
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AH interval
The time from the initial rapid deflection of the atrial wave to
the initial rapid deflection of the His bundle (H) potential; it
approximates the conduction time through the AV node (normally
50-120 msec).
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Ahaustral
Lacking haustra, smooth; describing the appearance of the colon on
radiographs of a barium enema in ulcerative colitis.
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AHF
Abbreviation for antihemophilic factor A.
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AHG
Abbreviation for antihemophilic globulin.
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AHI
Abbreviation for apnea-hypopnea index.
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AHMA
Abbreviation for the American Holistic Medical Association. An
association primarily for holistic medical physicians.
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aHyl
Symbol for allohydroxylysine.
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Ahylognosia
Inability to recognize differences in density, weight, and
coarseness.
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AI
Abbreviation for adequate intake. A recommended intake value based
on observed or experimentally determined approximations or
estimates of nutrient intake by a group of healthy people that are
assumed to be adequate. The AI is used when the recommended daily
allowance (RDA) cannot be determined.
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Aicardi syndrome
A rare genetic disorder characterized by infantile spasms
(jerking), absence of the corpus callosum (the connection between
the two hemispheres of the brain), mental retardation, and lesions
of the retina of the eye or optic nerve.
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Aichmophobia
Morbid fear of being touched by the finger or any slender pointed
object.
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Aid
1. Help; assistance. 2. A device that helps in the performance of
an action.
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AID
Abbreviation for activation-induced cytidine deaminase; artificial
insemination heterologous donor (insemination).
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Aidoi-
The genitals; corresponds to L. pudend-.
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AIDP
Abbreviation for acute inflammatory demyelinating
polyradiculoneuropathy.
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AIDS
Abbreviation for acquired immune deficiency syndrome. AIDS is
caused by the HIV (Human Immunodeficiency Virus) virus, which
attacks the immune system by destroying T4 helper/inducer
lymphocytes, leaving the infected individual vulnerable to
opportunistic infection.
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AIDS dementia complex
A subacute or chronic HIV-1 encephalitis, the most common
neurologic complication in the later stages of HIV infection;
manifested clinically as a progressive dementia, accompanied by
motor abnormalities.
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AIDS-associated lipodystrophy/insulin resistance syndrome
Common condition affecting patients with AIDS; onset seen usually
after initiation of HAART. Besides disfiguring lipodystrophy,
syndrome includes insulin resistance and marked dyslipidemia, along
with their attendant atherosclerotic complications.
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AIDS-related complex
Manifestations of AIDS in patients who have not yet developed major
deficient immune function, characterized by fever with generalized
lymphadenopathy, diarrhea, weight loss, minor opportunistic
infections, and cytopenias.
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AIDS-related virus
Obsolete term for human immunodeficiency virus.
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AIH
Abbreviation for autoimmune hepatitis; artificial insemination by
husband; artificial insemination, homologous.
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Aikido
Spiritual discipline and self-defense method that uses grappling,
throws, and "nonresistance" to debilitate opponents. The name
"aikido" combines three Japanese words: ai ("union" or "harmony"),
ki ("breath," "spirit" or "life force"), and do ("way"). Proponents
translate aikido as "the way of unifying ki" or "the way of harmony
with the spirit of the universe (or universal energy)." Morihei
Ueshiba (1883-1969), a Japanese farmer and master martial artist,
founded aikido sometime between 1922 and 1931, supposedly after a
divine revelation. Ueshiba claimed supernatural power. (His surname
is also spelled "Oyeshiba" and "Uyeshiba.") Practitioners may be
called "aikidoists."
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AILD
Abbreviation for angioimmunoblastic lymphadenopathy with
dysproteinemia.
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Ailurophobia
Morbid fear of or aversion to cats.
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Ainhum
An acquired, slowly progressive painful fibrous constriction that
develops in the digitoplantar fold, usually of the little toe,
gradually resulting in spontaneous amputation of the toe; most
commonly affects black males in the tropics.
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Air
A mixture of odorless gases found in the atmosphere in the
following approximate percentages by volume after water vapor has
been removed: oxygen, 20.95; nitrogen, 78.08; argon 0.93; carbon
dioxide, 0.03; other gases, 0.01.
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AIR
Abbreviation for 5-aminoimidazole ribose 5′-phosphate and
5-aminoimidazole ribotide.
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Air bladder
A gas-filled sac that is present in most fish and functions as a
hydrostatic organ; it is located beneath the vertebral column
primarily in the anterior abdomen and is connected with the
esophagus in some species (goldfish). Oxygen is transferred from a
rich venous sinus into the swim bladder to increase buoyancy.
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Air bronchiologram
Radiologic imaging pattern of small airways. A pattern of fine
air-containing structures thought to represent patent bronchioles
as viewed against a background of alveolar opacification.
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Air cells
Air-containing spaces in the skull.
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Air conduction
In relation to hearing, the transmission of sound to the inner ear
through the external auditory canal and the structures of the
middle ear.
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Air contrast enema
A radiographic double contrast enema in which air is introduced
after coating of the colon with a dense barium suspension.
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Air embolism
An embolism caused by air bubbles in the vascular system; venous
air embolism can result from the introduction of air through
intravenous lines, especially central lines, and generally must be
substantial to block pulmonary blood flow and cause symptoms;
arterial air embolism is also usually iatrogenic, caused by
cardiopulmonary bypass or other intravascular interventions, occurs
rarely after penetrating lung injury; small amounts of arterial air
can cause death by blockage of coronary and/or cerebral arteries;
small bubbles introduced into the venous system may similarly cause
symptoms if they reach the arterial side.
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Air hunger
Extremely deep ventilation such as occurs in patients with acidosis
attempting to increase ventilation of alveoli and exhale more
carbon dioxide.
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Air Kerma
The amount of Kerma in a specified mass of air; measured in Gray
(Gy); for x-rays with energies less than 300 kiloelectronvolts
(keV), 1 Gy = 100 rad. In air, 1 Gy of absorbed dose is delivered
by 114 roentgens (R) of exposure.
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Air pollution
Contamination of air by smoke and harmful gases, mainly oxides of
carbon, sulfur, and nitrogen, as from automobile exhausts,
industrial emissions, or burning rubbish.
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Air pumping cupping method
Form of cupping that requires a suction device, such as an "air
pumping cup."
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Air qi
The qi received from the air inhaled.
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Air splint
A plastic splint inflated by air used to immobilize part or all of
an extremity.
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Air tube
The trachea, or a bronchus or any of its branches conveying air to
the lungs.
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Air-bone gap
The difference between the thresholds for hearing when the stimuli
are delivered by air conduction and by bone conduction.
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Airborne infection
A mechanism of transmission of an infectious agent by particles,
dust, or droplet nuclei suspended in the air.
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Air-conditioner lung
An extrinsic allergic alveolitis caused by forced air contaminated
by thermophilic actinomycetes and other organisms.
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Air-fluid level
On an image made with a horizontal x-ray beam, a sharp flat
horizontal line representing the interface between gas density
above and fluid density below.
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Air-gap radiography
Chest radiography with a space of at least 10 inches between the
subject and the film. Instead of using a grid, this method uses the
geometry and x-ray absorption by the air to remove scattered
radiation.
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Air-gap technique
Chest radiography performed using a space between the subject and
the film instead of a grid to absorb scattered radiation; usually
requires a target-film distance of 10 feet.
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Airplane splint
A complex splint that holds the arm in abduction with the forearm
at approximately 90 degrees of flexion, generally with an axillary
strut for support.
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Airport malaria
Malaria inadvertently imported by transport of an infected
anopheline mosquito on an airplane.
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Airsickness
A condition resembling seasickness or other forms of motion
sickness occurring in airplane or space flight as a result of
erratic, increased, reduced, or continuous stimulation of the inner
ear.
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Airspace
Pertaining to the portion of the lung distal to the conducting
airways or bronchi; alveolar.
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Airtrapping
Slow or incomplete emptying of gas from all or part of a lung on
expiration; implies obstruction of regional airways or emphysema.
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Airway
1. Any part of the respiratory tract through which air passes
during breathing. 2. In anesthesia or resuscitation, a device for
correcting obstruction to breathing, especially an oropharyngeal
and nasopharyngeal airway, endotracheal airway, or tracheotomy
tube.
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Airway pattern
Chest radiographic appearance of thickened bronchial walls,
bronchiectasis, bronchiolitis, or acinar consolidation.
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Airway pressure release ventilation
Mechanical ventilation in which patients being treated with
continuous positive airway pressure have intermittent decreases
rather than increases in airway pressure and volume.
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Airway resistance
In physiology, the resistance to the flow of gases during
ventilation resulting from obstruction or turbulent flow in the
upper and lower airways; to be differentiated during inhalation
from resistance to inflation resulting from decreases in pulmonary
or thoracic compliance.
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Airy disc
The image of a circular blur formed by a distant point source of
light on the retina because of diffraction by the edge of the
pupillary aperture where the diameter of the image decreases as the
aperture increases.
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AJCC staging system
A system developed by the American Joint Committee on C