Glossary
G-5
Cerebrum
(ser
9
ĕ-brum) Te cerebral hemispheres (including the cere-
bral cortex, white matter, and basal nuclei).
Cervical vertebrae
Te seven vertebrae of the vertebral column located
in the neck.
Cervix
Lower outlet of the uterus extending into the vagina.
Channel
A transmembrane protein that forms an aqueous pore, allow-
ing substances to move from one side of the membrane to the other.
Chemical bond
An energy relationship holding atoms together; involves
the interaction of electrons.
Chemical energy
Energy stored in the bonds of chemical substances.
Chemical equilibrium
A state of apparent repose created by two reac-
tions proceeding in opposite directions at equal speed.
Chemical reaction
Process in which molecules are formed, changed, or
broken down.
Chemoreceptor
(ke
0
mo-re-sep
9
ter) Receptor sensitive to various chemi-
cals in solution.
Chemotaxis
(ke
0
mo-tak
9
sis) Movement of a cell, organism, or part of an
organism toward or away from a chemical substance.
Cholecystokinin (CCK)
(ko
0
le-sis
0
to-ki
9
nin) An intestinal hormone
that stimulates gallbladder contraction and pancreatic juice release.
Cholesterol
(ko-les
9
ter-ol
0
) Steroid found in animal fats as well as in
most body tissues; made by the liver.
Cholinergic fibers
(ko
0
lin-er
9
jik) Nerve endings that, upon stimulation,
release acetylcholine.
Chondroblast
(kon
9
dro-blast) Actively mitotic cell of cartilage.
Chondrocyte
(kon
9
dro-sīt) Mature cell of cartilage.
Chorion
(kor
9
e-on) Outermost fetal membrane; helps form the placenta.
Chorionic villus sampling
(ko
0
re-on
9
ik vil
9
us) Fetal testing procedure
in which bits of the chorionic villi from the placenta are snipped off and
the cells karyotyped. Tis procedure can be done as early as 8 weeks into
the pregnancy.
Choroid
(ko
9
roid) Te vascular middle layer of the eye.
Choroid plexus
(ko
9
roid plex
9
sus) A capillary knot that protrudes into a
brain ventricle; produces cerebrospinal fluid.
Chromatin
(kro
9
mah-tin) Structures in the nucleus that carry the he-
reditary factors (genes).
Chromosomes
(kro
9
mo-somz) Barlike bodies of tightly coiled chroma-
tin; visible during cell division.
Chronic obstructive pulmonary disease (COPD)
Collective term for
progressive, obstructive respiratory disorders; includes emphysema,
chronic bronchitis.
Chyme
(kīm) Semifluid, creamy mass consisting of partially digested
food and gastric juice.
Cilia
(sil
9
e-ah) ±iny, hairlike projections on cell surfaces that move in a
wavelike manner.
Circumduction
(ser
0
kum-duk
9
shun) Movement of a body part so that it
outlines a cone in space.
Cirrhosis
(sĭ-ro
9
sis) Chronic disease of the liver, characterized by an
overgrowth of connective tissue, or fibrosis.
Cisterna chyli
(sis-ter
9
nah ki
9
li) An enlarged sac at the base of the tho-
racic duct; the origin of the thoracic duct.
Cisternae
(sis-ter
9
ne) Any cavity or enclosed space serving as a reservoir.
Cleavage
An early embryonic phase consisting of rapid mitotic cell divi-
sions without intervening growth periods; product is a blastocyst.
Catabolism
(ka-tab
9
o-lizm) Process in which living cells break down
substances into simpler substances.
Catalyst
(kat
9
ah-list) Substance that increases the rate of a chemical reac-
tion without itself becoming chemically changed or part of the product.
Cataract
Clouding of the eye’s lens; o²en congenital or age-related.
Catecholamines
(kat
0
ĕ-kol
9
ah-mēnz) Epinephrine, norepinephrine, and
dopamine; a class of amines that act as chemical transmitters.
Cation
(kat
9
i-on) An ion with a positive charge.
Caudal
(kaw
9
dul) Literally, toward the tail; in humans, the inferior por-
tion of the anatomy.
Cecum
(se
9
kum) Te blind-ended pouch at the beginning of the large
intestine.
Cell
Structural unit of all living things.
Cell differentiation
Te development of specific and distinctive features
in cells, from a single cell (the fertilized egg) to all the specialized cells of
adulthood.
Cell cycle
Series of changes a cell goes through from the time it is formed
until it reproduces itself.
Cell membrane
See
Plasma membrane.
Cellular immunity
Immunity conferred by activated ± cells, which
directly kill infected or cancerous body cells or cells of foreign gra²s and
release chemicals that regulate the immune response. Also called cell-
mediated immunity.
Cellular respiration
Metabolic processes in which A±P is produced.
Cellulose
(sel
9
u-lōs) A fibrous carbohydrate that is the main structural
component of plant tissues.
Central (Haversian) canal
(hah-ver
9
zhan) Te canal in the center of
each osteon that contains minute blood vessels and nerve fibers that
serve the needs of the osteocytes.
Central nervous system (CNS)
Brain and spinal cord.
Centriole
(sen
9
tre-ol) Minute body found near the nucleus of the cell;
active in cell division.
Centrosome (cell center)
A region near the nucleus which contains
paired organelles called centrioles.
Cerebellum
(ser
0
ĕ-bel
9
um) Brain region most involved in producing
smooth, coordinated skeletal muscle activity.
Cerebral aqueduct
(ser
9
ĕ-bral, sĕ-re
9
bral) Te slender cavity of the mid-
brain that connects the third and fourth ventricles.
Cerebral arterial circle
(
circle of Willis
) An arterial anastomosis at the
base of the brain.
Cerebral cortex
Te outer gray matter region of the cerebral hemispheres.
Cerebral dominance
Designates the hemisphere that is dominant for
language.
Cerebral palsy
Neuromuscular disability in which voluntary muscles are
poorly controlled or paralyzed as a result of brain damage.
Cerebral white matter
Consists largely of myelinated fibers bundled
into large tracts; provides for communication between cerebral areas and
lower CNS centers.
Cerebrospinal fluid (CSF)
(ser
0
ĕ-bro-spi
9
nal) Plasmalike fluid that fills
the cavities of the CNS and surrounds the CNS externally; protects the
brain and spinal cord.
Cerebrovascular accident (CVA)
(ser
0
ĕ-bro-vas
9
ku-lar) Condition in
which brain tissue is deprived of a blood supply, as in blockage of a cere-
bral blood vessel; a stroke.
previous page 1181 Human Anatomy and Physiology (9th ed ) 2012 read online next page 1183 Human Anatomy and Physiology (9th ed ) 2012 read online Home Toggle text on/off