964
GLOSSARY
lysosome
(li
′
so-so
¯m)
Organelle that
contains digestive enzymes. p. 84
M
macromolecule
(mak
′
ro-mol
′
e
˘-ku
¯l)
Very large molecule. p. 4
macronutrient
(mak
′
ro-nu
′
tre-ent)
Nutrient (carbohydrate, lipid, and
protein) required in large amount.
p. 699
macrophage
(mak
′
ro-fa
¯j)
Large
phagocytic cell. p. 155
macula
(mak
′
u-lah)
Hair cells and
supporting cells associated with an
organ of static equilibrium. p. 459
macula lutea
(mak
′
u-lah lu
′
te-ah)
Yellowish depression in the retina of
the eye associated with acute vision.
p. 469
major histocompatibility complex
(ma
′
jo
˘r
his
″
to-kom-pat
″
ı˘-bil
′
ı˘-te kom
′
pleks)
Cluster of genes that code for cell
surface proteins; MHC. p. 630
major mineral
(ma
′
jor min
″
er-al)
Inorganic substance necessary
for metabolism that is part of a
group that accounts for 75% of the
mineral elements in the body; macro
mineral. p. 717
malignant
(mah-lig
′
nant)
The power to
threaten life; cancerous. p. 104
malnutrition
(mal
″
nu-trish
′
un)
Symptoms resulting from lack of
speciF c nutrients. p. 723
maltase
(mawl
′
ta
¯s)
Enzyme that
catalyzes breakdown of maltose into
glucose. p. 118
maltose
(mawl
′
to
¯s)
Disaccharide
composed of two glucose molecules.
p. 683
mammary
(mam
′
ar-e)
Pertaining to the
breast. p. 23
mammillary body
(mam
′
ı˘-lar
″
e bod
′
e)
One of two small, rounded bodies
posterior to the hypothalamus
involved with refl
exes associated
with the sense of smell. p. 407
marasmus
(mah-raz
′
mus)
Starvation due
to profound nutrient deF ciency. p. 726
marrow
(mar
′
o)
Connective tissue in
bones that includes stem cells. p. 195
mast cell
(mast sel)
Cell to which
antibodies, formed in reponse to
allergens attach, bursting the cell
and releasing allergy mediators.
p. 155
mastication
(mas
′
tı˘-ka
′
shun)
Chewing
movements. p. 656
matter
(mat
′
er)
Anything that has
weight and occupies space. p. 51
meatus
(me-a
′
tus)
Passageway or
channel, or the external opening of a
passageway. p. 208
tissue in the midline of the anterior
abdominal wall. p. 320
lingual
(ling
′
gwal)
Pertaining to the
tongue. p. 657
lingual frenulum
(ling
′
gwal fren
′
u-lum)
±old of tissue that anchors the
tongue to the fl
oor of the mouth.
p. 657
lipase
(lı¯
′
pa
¯s)
±at-digesting enzyme.
p. 118
lipid
(lip
′
id)
±at, oil, or fatlike compound
that usually has fatty acids in its
molecular structure. p. 62
lipoprotein
(lip
″
o-pro
′
te-in)
A complex
of lipid and protein. p. 684
liver
(liv
′
er)
Large, dark red organ in
the upper part of the abdomen on
the right side that detoxiF
es blood,
stores glycogen and fat-soluble
vitamins and synthesizes proteins,
including clotting factors and
enzymes. p. 673
lobule
(lob
′
ul)
Small, well-deF ned part
of an organ. p. 743
long-term synaptic potentiation
(long-
term sı˘-nap
′
tik po-ten
′
she-a-shun)
Theory that frequent, repeated
stimulation of the same neurons in
the hippocampus strengthens their
synaptic connections. p. 404
lower esophageal sphincter
(loh
′
er
e
˘-sof
″
ah-je
′
al sF ngk
′
ter)
Ring
of muscle, at the distal end of
the esophagus where it joins the
stomach, that prevents food from
re-entering the esophagus when the
stomach contracts; cardiac sphincter.
p. 665
lower limb
(loh
′
er lim)
Inferior
appendage consisting of the thigh,
leg, and foot. p. 234
lumbar
(lum
′
bar)
Pertaining to the
region of the loins, part of back
between the thorax and pelvis.
p. 23
lumen
(lu
′
men)
Space in a tubular
structure such as a blood vessel or
intestine. p. 653
luteinizing hormone
(lu
′
te-in-ı¯z
″
ing
hor
′
mo
¯n)
A hormone that the
anterior pituitary secretes that
controls formation of the corpus
luteum in females and testosterone
secretion in males. p. 497
lymph
(limf)
±luid that the lymphatic
vessels carry. p. 617
lymph node
(limf no
¯d)
Mass of
lymphoid tissue located along the
course of a lymphatic vessel.
p. 617
lymphocyte
(lim
′
fo-sı¯t)
Type of white
blood cell that provides immunity; B
cell or T cell. p. 532
lactase
(lak
′
ta
¯s)
Enzyme that catalyzes
breakdown of lactose into glucose
and galactose. p. 118
lacteal
(lak
′
te-al)
Lymphatic capillary
associated with a villus of the small
intestine. p. 681
lactic acid
(lak
′
tik as
′
id)
Organic
compound formed from pyruvic acid
during the anaerobic reactions of
cellular respiration. p. 122
lactose
(lak
′
to
¯s)
A disaccharide in milk;
milk sugar. p. 701
lacuna
(lah-ku
′
nah)
Hollow cavity.
p. 158
lamella
(lah-mel
′
ah)
Layer of matrix in
bone tissue. p. 160
lamellated corpuscle
(lah-mel
′
a-ted
kor
′
pusl)
Nerve endings deep in
the dermis providing perception of
pressure; Pacinian corpuscle. p. 440
large intestine
(lahrj in-tes
′
tin)
Part
of the gastrointestinal tract from
the ileum to the anus, divided into
the cecum, colon, rectum, and anal
canal. p. 686
laryngopharynx
(lah-ring
″
go-far
′
ingks)
Lower part of the pharynx near the
posterior to the larynx. p. 663
larynx
(lar
′
ingks)
Structure between
the pharynx and trachea that houses
the vocal cords. p. 740
latent period
(la
′
tent pe
′
re-od)
Time
between the application of a
stimulus and the beginning of a
response in a muscle F
ber. p. 296
lateral
(lat
′
er-al)
Pertaining to the side.
p. 21
leptin
(lep
′
tin)
Hormone, produced by
fat cells, that communicates with the
hypothalamus to indicate the degree
of hunger. p. 700
leukocyte
(lu
′
ko-sı¯t)
White blood cell.
p. 530
leukocytosis
(lu
″
ko-si-to
′
sis)
Too many
white blood cells in the blood.
p. 533
leukopenia
(lu
″
ko-pe
′
ne-ah)
Too few
white blood cells in the blood.
p. 533
lever
(lev
′
er)
Simple mechanical
device consisting of a rod, fulcrum,
weight, and a source of energy that
is applied to some point on the rod.
p. 301
ligament
(lig
′
ah-ment)
Cord or sheet
of connective tissue binding two or
more bones at a joint. p. 155
limbic system
(lim
′
bik sis
′
tem)
Connected structures in the brain
that produce emotional feelings.
p. 407
linea alba
(lin
′
e-ah al
′
bah)
Narrow
band of tendinous connective
