1. The most strongly accented syllable appears in capital letters, for
example, bilateral (bT-LAT-er-al) and diagnosis (dl-ag-NO-sis).
2. If there is a secondary accent, it is noted by a prime ('), for example,
constitution (kon'-sti-TOO-shun) and physiology (fiz'-e-OL-o-je).
Any additional secondary accents are also noted by a prime, for
example, decarboxylation (de'-kar-bok'-si-LA-shun).
3. Vowels marked by a line above the letter are pronounced with the
long sound, as in the following common words:
m a k e
p o le
c u te
4. Vowels not marked by a line above the letter are pronounced
with the short sound, as in the following words:
a b o v e
n o t
b e t
b u d
5. Other vowel sounds are indicated as follows:
r o o t
6. Consonant sounds are pronounced as in the following words:
b a t
c h a ir
d o g
f a th e r
g e t
h a t
ju m p
c a n
t a x
q u it
m o t h e r
p ic k
v e r y
w e lc o m e
z e r o
le s io n
AB-do-men) The area between the dia-
phragm and pelvis.
Abdominal cavity (ab-DOM-i-nal) Superior portion of the abdominopelvic
cavity that contains the stomach, spleen, liver, gallbladder, most
of the small intestine, and part of the large intestine.
Abdominal thrust maneuver A first-aid procedure for choking.
Employs a quick, upward thrust against the diaphragm that forces
air out of the lungs with sufficient force to eject any lodged mate-
rial. Also called the Heimlich maneuver (HTM-lik).
Abdominopelvic cavity (ab-dom'-i-no-PEL-vic) A body cavity that is
subdivided into a superior abdominal cavity and an inferior pelvic
Abduction (ab-DUK-shun) Movement away from the midline of the body.
Abortion (a-BOR-shun) The premature loss (spontaneous) or removal
(induced) of the embryo or nonviable fetus; miscarriage due to a
failure in the normal process of developing or maturing.
Abscess (AB-ses) A localized collection of pus and liquefied tissue in
Absorption (ab-SORP-shun) Intake of fluids or other substances by
cells of the skin or mucous membranes; the passage of digested
foods from the gastrointestinal tract into blood or lymph.
Accommodation (a-kom-o-DA-shun) An increase in the curvature of
the lens of the eye to adjust for near vision.
Acetabulum (as'-e-TAB-u-lum) The rounded cavity on the external
surface of the hip bone that receives the head of the femur.
Acetylcholine (ACh) (as'-e-til-KO-len) A neurotransmitter liberated by
many peripheral nervous system neurons and some central nervous
system neurons. It is excitatory at neuromuscular junctions but
inhibitory at some other synapses (for example, it slows heart rate).
Achalasia (ak'-a-LA-ze-a) A condition, in which the lower esophageal
sphincter fails to relax normally as food approaches. A whole
meal may become lodged in the esophagus and enter the stom-
ach very slowly. Distension of the esophagus results in chest pain
that is often confused with pain originating from the heart.
Acid (AS-id) A proton donor, or a substance that dissociates into
hydrogen ions (H+); characterized by an excess of hydrogen ions
and a pH less than 7.
Acidosis (as-i-DO-sis) A condition in which blood pH is below 7.35.
Also known as acidemia.
Acini (AS-i-ne) Groups of cells in the pancreas that secrete digestive
Acoustic (a-KOOS-tik) Pertaining to sound or the sense of hearing.
Acquired immunodeficiency syndrome (AIDS) A disease caused by
the human immunodeficiency virus (HIV). Characterized by a posi-
tive HIV-antibody test, low helper T cell count, and certain indica-
tor diseases (for example Kaposi's sarcoma,
P n e u m o c y s tis c a r in ii
pneumonia, tuberculosis, fungal diseases). Other symptoms
include fever or night sweats, coughing, sore throat, fatigue,
body aches, weight loss, and enlarged lymph nodes.
Acrosome (AK-ro-som) A lysosomelike organelle in the head of a
sperm cell containing enzymes that facilitate the penetration of a
sperm cell into a secondary oocyte.
Actin (AK-tin) A contractile protein that is part of the thin filaments in
Action potential An electrical signal that propagates along the
membrane of a neuron or muscle fiber (cell); a rapid change in
membrane potential that involves a depolarization followed by
a repolarization. Also called a nerve action potential or nerve
impulse as it relates to a neuron, and a muscle action potential as
it relates to a muscle fiber.
Active transport The movement of substances across cell mem-
branes against a concentration gradient, requiring the expendi-
ture of cellular energy (ATP).
Acute (a-KOT) Having rapid onset, severe symptoms, and a short
course; not chronic.