951
GLOSSARY
Each word in this glossary is followed by
a phonetic guide to pronunciation. In this
guide, any unmarked vowel that ends a syl-
lable or stands alone as a syllable has the
long sound. Thus,
play
would be spelled
pla.
Any unmarked vowel that is followed
by a consonant has the short sound.
Tough,
for instance, is spelled
tuf.
If a long vowel
appears in the middle of a syllable (fol-
lowed by a consonant), it is marked with
the macron (¯), the sign for a long vowel.
Thus, the word
plate
would be phonetically
spelled pl
a
¯
t. Similarly, if a vowel stands
alone or ends a syllable, but has the short
sound, it is marked with a breve (˘).
A
abdominal
(ab-dom
′
ı˘-nal)
Pertaining to
the portion of the body between the
diaphragm and the pelvis. p. 23
abdominal cavity
(ab-dom
′
ı˘-nal kav
′
ı˘-te
¯)
Space between the diaphragm and
the pelvic inlet that contains the
abdominal viscera. p. 12
abdominopelvic cavity
(ab-dom
″
ı˘-no-
pel
′
vik kav
′
ı˘-te
¯)
Space between the
diaphragm and the lower portion of
the trunk of the body. p. 12
abduction
(ab-duk
′
shun)
Movement of
a body part away from the midline.
p. 269
absorption
(ab-sorp
′
shun)
The taking
in of substances by cells or across
membranes. p. 8
accessory organ
(ak-ses
′
o-re or
′
gan)
Organ that supplements the
functions of other organs. p. 833
accommodation
(ah-kom
″
o-da
′
shun)
Adjustment of the lens of the eye for
close or distant vision. p. 487
acetylcholine
(as
″
e
˘-til-ko
′
le
¯n)
Type
of neurotransmitter, which is a
biochemical secreted at axon ends
of many neurons; transmits nerve
impulses across synapses; ACH.
p. 290
acetylcholinesterase
(as
″
e
˘-til-ko
″
lin-
es
′
ter-a
¯s)
Enzyme that catalyzes
breakdown of acetylcholine. p. 293
acetyl coenzyme
A
(as
′
e
˘-til ko-en
′
zı¯m)
Intermediate compound produced
from the oxidation of carbohydrates
and fats. p. 122
acid
(as
′
id)
Substance that ionizes in
water to release hydrogen ions.
p. 59
acid-base buffer system
(as
′
id-ba
¯s buf
′
er
sis
′
tem)
Pair of chemicals, one a
weak acid, the other a weak base,
that resists pH changes. p. 820
acidosis
(as
″
ı˘-do
′
sis)
Increase in acidity
of body fl
uids below pH 7.35. p. 60
acoustic
(ah-koo-s
′
tik)
Pertaining to
sound. p. 450
acromial
(ah-kro
′
me-al)
Pertaining to
the shoulder. p. 23
ACTH
Adrenocorticotropic hormone.
p. 496
actin
(ak
′
tin)
A protein in a muscle
F ber that forms F laments that slide
between F
laments of the protein
myosin, contracting muscle F
bers.
p. 287
action potential
(ak
′
shun po-ten
′
shal)
Sequence of electrical changes
in part of a nerve cell membrane
exposed to a stimulus that exceeds
threshold. p. 368
activation energy
(ak
″
tı˘-va
′
shun
en
′
er-je)
Energy required to initiate
a chemical reaction. p. 117
active site
(ak
′
tiv sı¯t)
Part of an
enzyme that temporarily binds a
substrate. p. 117
active transport
(ak
′
tiv trans
′
port)
Process that requires energy and
a carrier molecule to move a
substance across a cell membrane,
usually against the concentration
gradient. p. 95
adaptive defense
(a-dap
′
tiv de
¯-fenc)
SpeciF c defenses T and B
lymphocytes carry out. p. 626
adduction
(ah-duk
′
shun)
Movement of
a body part toward the midline.
p. 269
adenoids
(ad
′
e
˘-noids)
The pharyngeal
tonsils in the nasopharynx. p. 657
adenosine diphosphate
(ah-den
′
o-se
¯n
di-fos
′
fa
¯t)
Molecule produced
when adenosine triphosphate loses a
terminal phosphate; ADP. p. 119
adenosine triphosphate
(ah-den
′
o-se
¯n
tri-fos
′
fa
¯t)
Organic molecule that
stores and releases energy, used in
cellular processes; ATP. p. 84
adenylate cyclase
(ah-den
′
ı˘-la
¯t si
′
kla
¯s)
Enzyme activated when certain
hormones bind receptors on
cell membranes. It catalyzes the
circularization of ATP to cyclic AMP.
p. 488
ADH
Antidiuretic hormone. p. 498
adipose tissue
(ad
′
ı˘-po
¯s tish
′
u)
±at-
storing tissue. p. 156
adolescence
(ad
″
o-les
′
ens)
Period of life
between puberty and adulthood.
p. 906
ADP
Adenosine diphosphate. p. 119
adrenal cortex
(ah-dre
′
nal kor
′
teks)
Outer part of the adrenal gland.
p. 504
adrenal gland
(ah-dre
′
nal gland)
Endocrine gland on the superior
portion of each kidney. p. 504
adrenalin
(ah-dren
′
ah-lin)
Epinephrine.
Adrenal gland hormone. p. 505
adrenal medulla
(ah-dre
′
nal me-dul
′
ah)
Inner part of the adrenal gland.
p. 504
adrenergic F
ber
(ad
″
ren-er
′
jik F
′
ber)
Axon that secretes norepinephrine at
its terminal. p. 429
adrenocorticotropic hormone
(ah-dre
″
no-kor
″
te-ko-tro
¯p
′
ik hor
′
mo
¯n)
Hormone that the anterior pituitary
secretes to stimulate activity in the
adrenal cortex; ACTH. p. 496
adulthood
(ah-dult
′
hood)
Period
of life between adolescence and
senescence. p. 907
