963
GLOSSARY
isotope
(i
′
so-to
¯p)
Atom that has the same
number of protons as other atoms of
an element but has a different number
of neutrons in its nucleus. p. 53
isthmus
(is
′
mus)
Narrow connection
between two larger parts. p. 499
J
jejunum
(je
˘-joo
′
num)
Part of the small
intestine between the duodenum
and the ileum. p. 680
joint capsule
(joint kap
′
sul)
An
envelope, attached to the end of
each bone at the joint, enclosing
the cavity of a synovial joint.
p. 264
juxtaglomerular apparatus
(juks
″
tah-glo-
mer
′
u-la
¯r ap
″
ah-ra
′
tus)
A group
of cells in the wall of the afferent
arteriole in the kidney that plays a
role in the control of renin secretion.
p. 784
juxtamedullary nephron
(juks
″
tah-
med
′
u- la
¯r-e nef
′
ron)
A nephron
with its corpuscle near the renal
medulla. p. 784
K
karyotype
(kar
′
e
¯-o-tı¯p)
A chart of
the chromosomes arranged in
size-ordered homologous pairs.
The human karyotype has 23
chromosome pairs. p. 918
keratin
(ker
′
ah-tin)
Protein in
epidermis, hair, and nails. p. 147
keratinization
(ker
″
ah-tin
″
ı˘-za
′
shun)
Process by which cells form F
brils of
keratin and harden. p. 173
ketone body
(ke
′
to
¯n bod
′
e)
Type
of compound produced during
fat catabolism, including
acetone, acetoacetic acid, and
betahydroxybutyric acid. p. 703
Kupffer cell
(koop
′
fer sel)
Large, F
xed
phagocyte in the liver that removes
bacterial cells from the blood.
p. 673
kwashiorkor
(kwash
″
e-or
′
kor)
Starvation resulting from a switch
from breast milk to food deF
cient in
protein. p. 726
L
labor
(la
′
bor)
Process of childbirth.
p. 900
labyrinth
(lab
′
ı˘-rinth)
System of
connecting tubes in the inner ear,
including the cochlea, vestibule, and
semicircular canals. p. 453
lacrimal gland
(lak
′
rı˘-mal gland)
Tear-
secreting gland. p. 463
interneuron
(in
″
ter-nu
′
ron)
Neuron
between a sensory neuron and
a motor neuron; intercalated;
internuncial, or association neuron.
p. 361
interphase
(in
′
ter-fa
¯z)
Period between
two cell divisions when a cell
metabolizes and prepares for
division. p. 100
interstitial cell
(in
″
ter-stish
′
al sel)
Hormone-secreting cell between the
seminiferous tubules of the testis.
p. 835
intervertebral disc
(in
″
ter-ver
′
te
˘-bral
disk)
Layer of F
brocartilage
between the bodies of adjacent
vertebrae. p. 206
intestinal gland
(in-tes
′
tı˘-nal gland)
Tubular gland at the base of a villus
in the intestinal wall. p. 681
intracellular fl
uid
(in
″
trah-sel
′
u-lar
fl oo
′
id)
±luid in cells. p. 812
intramembranous bone
(in
″
trah-
mem
′
brah-nus bo
¯n)
Bone that
forms from membranelike layers of
primitive connective tissue. p. 197
intrauterine device
(in
″
trah-u
′
ter-
in de-vı¯s)
Solid object placed
in the uterine cavity to prevent
implantation of a fertilized ovum;
IUD. p. 866
intrinsic factor
(in-trin
′
sik fak
′
tor)
Substance that gastric glands
produce to promote absorption of
vitamin B
12
. p. 528
inversion
(in-ver
′
zhun)
Turning the
sole of the foot inward. p. 269
involuntary
(in-vol
′
un-ta
¯r
″
e)
Not
consciously controlled; functions
automatically. p. 163
ion
(i
′
on)
Atom or molecule with an
electrical charge. p. 55
ionic bond
(i-on
′
ik bond)
Chemical
bond formed between two ions by
transfer of electrons; electrovalent
bond. p. 55
ipsilateral
(ip
″
sı¯-lat
′
er-al)
On the same
side. p. 21
iris
(i
′
ris)
Colored, muscular part of the
eye around the pupil that regulates
its size. p. 467
ischemia
(is-ke
′
me-ah)
DeF ciency of
blood in a body part. p. 440
isometric contraction
(i
″
so-met
′
rik kon-
trak
′
shun)
Muscular contraction
that does not change the muscle
length. p. 298
isotonic
(i
″
so-ton
′
ik)
Solution with
the same osmotic pressure as the
solution with which it is compared
(usually body fl
uids). p. 94
isotonic contraction
(i
″
so-ton
′
ik kon-
trak
′
shun)
Muscular contraction that
changes the muscle length. p. 298
inferior
(in-fe
¯r
′
e-or)
Situated below
something else; pertaining to the
lower surface of a part. p. 21
infl
ammation
(in
″
fl
ah-ma
′
shun)
Tissue
response to stress that includes
dilation of blood vessels and fl
uid
accumulation in the affected region.
p. 183
infundibulum
(in
″
fun-dib
′
u-lum)
Stalk
attaching the pituitary gland to the
base of the brain. p. 405
inguinal
(ing
′
gwı˘-nal)
Pertaining to the
groin region. p. 23
inguinal canal
(ing
′
gwı˘-nal kah-nal
′
)
Passage in the lower abdominal wall
through which a testis descends into
the scrotum. p. 833
inhibin
(in
′
hib
′
in)
Hormone secreted
by cells of the testes and ovaries that
inhibits the secretion of ±SH from
the anterior pituitary gland. p. 845
innate defense
(in-na
¯t
′
de-fens
′
)
Inborn,
nonspeciF c defense that blocks entry
of or destroys pathogens. p. 626
inorganic
(in
″
or-gan
′
ik)
Chemical
that does not include carbon and
hydrogen atoms. p. 60
insertion
(in-ser
′
shun)
End of a muscle
attached to a movable part. p. 303
inspiration
(in
″
spı˘-ra
′
shun)
Breathing
in; inhalation. p. 747
inspiratory capacity
(in-spi
′
rah-to
″
re
kah-pas
′
i-te)
Volume of air equal to
the tidal volume plus the inspiratory
reserve volume. p. 753
inspiratory reserve volume
(in-spi
′
rah-
to
″
re re-zerv
′
vol
′
u
¯m)
Amount of
air that can be inhaled in addition to
the tidal volume. p. 752
insula
(in
′
su-lah)
Cerebral lobe deep
within the lateral sulcus. p. 400
insulin
(in
′
su-lin)
Hormone the
pancreatic islets secrete that stimulates
cells to take up glucose. p. 93
integumentary
(in-teg-u-men
′
tar-e)
Pertaining to the skin and its
accessory organs. p. 14
intercalated disc
(in-ter
″
ka
¯h-la
¯t
′
ed disk)
Membranous boundary between
adjacent cardiac muscle cells. p. 301
intercellular junction
(in
″
ter-sel
′
u-lar
junk
′
shun)
Site of union between
cells. p. 144
interferon
(in
″
ter-fe
¯r
′
on)
Class of
immune system chemicals (cytokines)
that inhibit multiplication of viruses
and growth of tumors. p. 626
interleukin
(in
″
ter-lu
′
kin)
Class
of immune system chemicals
(cytokines) with varied effects. p. 530
internal environment
(in-ter
′
nal en-vi
′
ron-
ment)
Conditions and elements
that make up the inside of the body,
surrounding the cells. p. 9
