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Saladin: Anatomy &
Physiology: The Unity of
Form and Function, Third
Edition
29. Human Development Text
© The McGraw−Hill
Companies, 2003
Chapter 29
Chapter 29 Human Development 1117
Fertilization and Preembryonic
Development (p. 1090)
1. Sperm must travel to the distal one-
third of the uterine tube if they are to
encounter the egg before it dies. This
traveling, or sperm migration, may be
aided by the cervical mucus, female
orgasm, and chemical attractants
emitted by the egg.
2. Freshly ejaculated sperm cannot
fertilize an egg. They undergo
capacitation, becoming capable of
fertilization, as they migrate.
3. When a sperm encounters an egg, it
releases enzymes from its acrosome
(the acrosomal reaction), enabling it
to penetrate the cumulus oophorus,
zone pellucida, and egg membrane.
Hundreds of sperm may be needed to
clear a path for the one that fertilizes
the egg.

4. The egg has a fast block and a slow
block to prevent fertilization by more
than one sperm (polyspermy). The
fast block employs a change in egg
membrane voltage that inhibits the
binding of additional sperm. The
slow block involves exocytosis of
the egg’s cortical granules to produce
an impenetrable fertilization
membrane around the egg.
5. The fertilized egg completes meiosis
II and casts off a second polar body.
The sperm and egg nuclei swell and
form pronuclei. When the pronuclei
rupture and their chromosomes
mingle, the egg is a diploid zygote.
6. The first two weeks of development,
called the preembryonic stage,
consists of cleavage, implantation,
and embryogenesis, resulting in an
embryo.
7. Cleavage is the mitotic division of the
zygote into cells called blastomeres.
The stage that arrives at the uterus is
a morula of about 16 blastomeres. It
develops into a hollow ball called the
blastocyst, with an outer cell mass
called the trophoblast and inner cell
mass called the embryoblast.
8. Implantation is the attachment of the

blastocyst to the uterine wall. The
trophoblast differentiates into a
cellular mass called the
cytotrophoblast next to the embryo,
and a multinucleate mass called the
syncytiotrophoblast, which grows
rootlets into the endometrium. The
endometrium grows over the
blastocyst and soon completely
covers it.
9. The trophoblast secretes human
chorionic gonadotropin, the hormone
that stimulates growth and secretion
by the corpus luteum.
10. During implantation, the embryoblast
differentiates into three primary germ
layers—ectoderm, mesoderm, and
endoderm. This process is
embryogenesis. When the three
primary germ layers have formed, 2
weeks after conception, the
individual is an embryo.
Embryonic and Fetal
Development (p. 1094)
1. The next 6 weeks of development are
marked by formation of the extra-
embryonic membranes, placental
nutrition, and appearance of the
organ systems.
2. After implantation, the conceptus is

fed by trophoblastic nutrition, in
which the trophoblast digests
decidual cells of the endometrium.
This is the dominant mode of
nutrition for 8 weeks.
3. The placenta begins to form 11 days
after conception as chorionic villi of
the trophoblast eat into uterine blood
vessels, eventually creating a blood-
filled cavity called the placental
sinus. The chorionic villi grow into
branched treelike structures
surrounded by the maternal blood in
the sinus. Nutrients diffuse from the
maternal blood into embryonic blood
vessels in the villi, and embryonic
wastes diffuse the other way to be
disposed of by the mother. Placental
nutrition becomes dominant at 8
weeks and continues until birth.
4. The placenta communicates with the
embryo and fetus by way of two
arteries and a vein contained in the
umbilical cord.
5. Four membranes are associated with
the embryo and fetus: the amnion,
yolk sac, allantois, and chorion.
6. The amnion is a translucent sac that
encloses the embryo in a pool of
amniotic fluid. This fluid protects the

embryo from trauma and temperature
fluctuations and allows freedom of
movement and symmetric
development.
7. The yolk sac contributes to
development of the digestive tract
and produces the first blood and
germ cells of the embryo.
8. The allantois is an outgrowth of the
yolk sac that forms a structural
foundation for umbilical cord
development and becomes part of the
urinary bladder.
9. The chorion encloses all of the other
membranes and forms the fetal part of
the placenta.
10. Organogenesis is the differentiation
of the primary germ layers into all of
the organs and organ systems (table
29.2). Traces of all organ systems are
present by the end of 8 weeks. The
individual is considered a fetus from
then until birth.
11. In the fetal stage, organs undergo
growth and differentiation and
become capable of functioning
outside the mother’s body. Major
developments in the fetal stage are
summarized in table 29.4.
12. The circulatory system differs most

markedly from prenatal to neonatal
life. In the fetus, a pair of umbilical
arteries arise from the internal iliac
arteries and supply the placenta. A
single umbilical vein returns from the
placenta and drains most of its blood
into the inferior vena cava (IVC).
13. Three bypasses or shunts divert fetal
blood from organs that are not very
functional before birth: The ductus
venosus bypasses the liver and
carries most umbilical vein blood
directly to the IVC; the foramen ovale
in the interatrial septum of the heart
Chapter Review
Review of Key Concepts
Saladin: Anatomy &
Physiology: The Unity of
Form and Function, Third
Edition
29. Human Development Text
© The McGraw−Hill
Companies, 2003
Chapter 29
1118 Part Five Reproduction and Development
allows blood to pass directly from the
right atrium to the left atrium,
bypassing the lungs; and the ductus
arteriosus allows blood in the
pulmonary trunk to pass directly into

the aorta and bypass the lungs.
The Neonate (p. 1101)
1. The first 6 to 8 hours after birth are a
transitional period marked by
increasing heart and respiratory rates
and falling temperature. The first 6
weeks of postpartum life are the
neonatal period.
2. After severance of the umbilical cord,
the proximal parts of the umbilical
arteries become vesical arteries,
which supply the urinary bladder.
Other blood vessels unique to the
fetus close and become fibrous cords
or ligaments. The foramen ovale and
ductus arteriosus close so that blood
from the right heart is forced to
circulate through the lungs.
3. Breathing is very difficult for the
neonate as it first inflates the
pulmonary alveoli.
4. Neonatal immunity depends heavily
on IgG acquired through the placenta
and IgA from colostrum. By 6
months, the infant produces ample
IgG of its own.
5. Neonatal thermoregulation is critical
because infants lose heat easily. This
heat loss is compensated for to some
extent by a form of heat-producing

adipose tissue called brown fat.
6. The neonatal kidneys are not very
efficient at concentrating urine, so
neonates have a relatively high rate of
water loss and require more fluid
intake than adults do relative to their
body weight.
7. Premature infants suffer especially
from respiratory distress syndrome,
poor thermoregulation, poor fat
digestion, and multiple dysfunctions
resulting from inadequate liver
function.
8. Congenital anomalies (birth defects)
can result from infectious diseases,
teratogens, mutagens, and genetic
disorders.
9. Some of the more common and
serious infectious diseases and
pathogens of the newborn are herpes
simplex, cytomegalovirus, HIV,
gonorrhea, and syphilis.
10. Teratogens, agents that cause
anatomical deformities, include
alcohol, nicotine, and X rays.
11. Nondisjunction, the failure of
homologous chromosomes to separate
during meiosis, can result in such
congenital defects as triplo-X,
Klinefelter, Turner, and Down

syndromes.
Aging and Senescence (p. 1107)
1. Senescence is the degeneration that
occurs in an organ system as we age.
It begins at very different ages and
progresses at different rates in
different organ systems. Senescence
of one organ system often contributes
to the senescence of others.
2. Senescence of the integumentary
system is marked by graying and
thinning of the hair, atrophy of
sebaceous glands, thinning and loss
of elasticity in the skin, fragility of
cutaneous blood vessels, decline in
cutaneous sensory function, slower
healing, and poorer thermoregulation.
Intrinsic aging occurs inevitably with
time, while photoaging is an added
effect proportional to the amount of
lifetime UV exposure. Senescence of
the skin contributes to lactose
intolerance, bone loss, muscle
weakness, and poorer glandular
secretion and synaptic transmission.
3. Senescence of the skeletal system is
marked by loss of bone density
(osteopenia or, when more severe,
osteoporosis), increasing
susceptibility to fractures, slower

healing of fractures, osteoarthritis,
and other degenerative joint diseases.
4. The aging muscular system exhibits
muscular atrophy, loss of strength, and
easy fatigue. Some loss of muscular
function results from degenerative
changes in the nervous system.
5. Senescence of the nervous system is
marked by substantial loss of brain
tissue and synapses, less efficient
synaptic transmission, and declining
motor coordination, intellectual
function, and short-term memory, but
relatively little loss of language skills
and long-term memory. Senescence of
the sympathetic division results in
less effective homeostasis in other
organ systems.
6. Visual acuity and auditory sensitivity
begin to decline shortly after
adolescence. Vision can be impaired
by cataracts, glaucoma, and reduced
dark adaptation. Declining inner-ear
function can result in poor balance.
Taste and smell become less sensitive.
7. The endocrine system shows
relatively little senescence except
for the decline in reproductive
hormones. Reduced densities of
hormone receptors can contribute to

type II diabetes mellitus and poorer
negative feedback control of the
pituitary.
8. Senescence of the circulatory system
is a leading cause of death. Anemia,
atherosclerosis, thrombosis, varicose
veins, hemorrhoids, and edema
become more common in old age.
Atherosclerosis contributes to
weakening of the heart, myocardial
infarction, aneurysm, stroke, and
atrophy of all organs.
9. Senescence of the immune system
makes older people more subject to
cancer and infectious diseases.
10. Pulmonary functions decline as the
thoracic cage becomes less flexible
and the lungs have fewer alveoli.
Pneumonia and chronic obstructive
pulmonary diseases are major causes
of death.
11. The kidneys atrophy a great deal with
age, and thus elderly people are less
able to maintain water balance and to
clear drugs or toxins from the body.
Elderly men are increasingly subject
to prostatic enlargement and urine
retention, and women to urinary
incontinence.
12. Senescence of the digestive system

includes reduced salivation,
difficulty swallowing, poorer dental
health, atrophy of the stomach,
gastroesophageal reflux, constipation,
loss of appetite, and impaired liver
function.
13. Reproductive senescence is marked
in men by reduced testosterone
secretion, sperm count, and libido,
and in women by menopause and
multiple effects of the loss of estrogen
secretion.
14. Exercise slows the rate of senescence
and improves the quality of life in old
age by maintaining strength,
endurance, flexibility, and
independence. It reduces the
incidence and severity of
hypertension, osteoporosis, obesity,
and diabetes mellitus.
15. There are numerous theories of what
causes senescence. Replicative
senescence, a limit on how many
times cells can divide, may stem from
shortening of the chromosomal
telomeres at each cell division. Cross-
Saladin: Anatomy &
Physiology: The Unity of
Form and Function, Third
Edition

29. Human Development Text
© The McGraw−Hill
Companies, 2003
Chapter 29
Chapter 29 Human Development 1119
linking of proteins and DNA and the
misfolding and other structural
defects in proteins may cause
increasing cellular dysfunction. The
cumulative effects of free radical
damage and increased incidence of
autoimmune disease may be other
factors in senescence.
16. Longevity is known to be partially
hereditary. Natural selection has
presumably been unable to eliminate
genes that cause some of the diseases
of old age because such genes have
no effects that natural selection can
act on until after the individual has
reproduced.
17. Life expectancy has increased in
modern times mostly because of our
ability to reduce infant and
childhood mortality. Life span, the
maximum attainable age, has not
markedly changed, however.
18. Death is usually clinically defined by
an absence of brain waves, reflexes,
or spontaneous respiration or

heartbeat.
Selected Vocabulary
capacitation 1090
acrosomal reaction 1090
zygote 1091
morula 1091
blastocyst 1093
implantation 1093
embryo 1094
placenta 1095
amnion 1097
chorion 1098
fetus 1098
meconium 1101
lanugo 1101
vernix caseosa 1101
teratogen 1104
senescence 1107
telomere 1113
Testing Your Recall
1. When a conceptus arrives in the
uterus, it is at what stage of
development?
a. zygote
b. morula
c. blastomere
d. blastocyst
e. embryo
2. The entry of a sperm nucleus into an
egg must be preceded by

a. the cortical reaction.
b. the acrosomal reaction.
c. the fast block.
d. implantation.
e. cleavage.
3. The stage of the conceptus that
implants in the uterine wall is
a. a blastomere.
b. a morula.
c. a blastocyst.
d. an embryo.
e. a zygote.
4. Chorionic villi develop from
a. the zona pellucida.
b. the endometrium.
c. the syncytiotrophoblast.
d. the embryoblast.
e. the corona radiata.
5. Which of these results from
aneuploidy?
a. Turner syndrome
b. fetal alcohol syndrome
c. nondisjunction
d. progeria
e. rubella
6. Fetal urine accumulates in the _______
and contributes to the fluid there.
a. placental sinus
b. yolk sac
c. allantois

d. chorion
e. amnion
7. One theory of senescence is that
it results from a lifetime of
damage by
a. teratogens.
b. aneuploidy.
c. free radicals.
d. cytomegalovirus.
e. nondisjunction.
8. Photoaging is a major factor in the
senescence of
a. the integumentary system.
b. the eyes.
c. the nervous system.
d. the skeletal system.
e. the cardiovascular system.
9. Which of these is not a common
effect of senescence?
a. reduced synthesis of vitamin D
b. atrophy of the kidneys
c. atrophy of the cerebral gyri
d. increased herniation of
intervertebral discs
e. reduced pulmonary vital
capacity
10. For the first 8 weeks of gestation, a
conceptus is nourished mainly by
a. the placenta.
b. amniotic fluid.

c. colostrum.
d. decidual cells.
e. yolk cytoplasm.
11. Viruses and chemicals that cause
congenital anatomical deformities are
called _______.
12. Aneuploidy is caused by _______, the
failure of two homologous
chromosomes to separate in
meiosis.
13. The maximum age attainable by a
member of the human species is
called the _______.
14. The average age attained by humans
in a given population is called the
_______.
15. Fetal blood flows through growths
called _______, which project into the
placental sinus.
16. The enzymes with which a sperm
penetrates an egg are contained in an
organelle called the _______.
17. Stiffening of the arteries, joints, and
lenses in old age may be a result of
cross-linking between _______
molecules.
Saladin: Anatomy &
Physiology: The Unity of
Form and Function, Third
Edition

29. Human Development Text
© The McGraw−Hill
Companies, 2003
Chapter 29
1120 Part Five Reproduction and Development
18. An enlarged tongue, epicanthal folds
of the eyes, and mental retardation
are characteristic of a genetic
anomaly called _______.
19. The fossa ovalis is a remnant of a
fetal shunt called the _______.
20. A developing individual is first
classified as a/an _______ when the
three primary germ layers have
formed.
Answers in Appendix B
Answers in Appendix B
True or False
Determine which five of the following
statements are false, and briefly
explain why.
1. Freshly ejaculated sperm are more
capable of fertilizing an egg than are
sperm several hours old.
2. Fertilization normally occurs in the
lumen of the uterus.
3. An egg is usually fertilized by the
first sperm that contacts it.
4. By the time a conceptus reaches the
uterus, it has already undergone

several cell divisions and consists of
16 cells or more.
5. The conceptus is first considered a
fetus when all of the organ systems
are present.
6. The placenta becomes increasingly
permeable as it develops.
7. The endocrine system shows less
senescence in old age than most other
organ systems.
8. Fetal blood bypasses the
nonfunctional liver by passing
through the foramen ovale.
9. Blood in the umbilical vein has a
higher P
O
2
than blood in the
umbilical arteries.
10. It is well established that people who
exercise regularly live longer than
those who do not.
Testing Your Comprehension
1. Suppose a woman had a mutation
resulting in a tough zona pellucida
that did not disintegrate after the egg
was fertilized. How would this affect
her fertility? Why?
2. Suppose a drug were developed that
could slow down the rate of collagen

cross-linking with age. What diseases
of old age could be made less severe
with such a drug?
3. Some health-food stores market the
enzyme superoxide dismutase (SOD)
as an oral antioxidant to retard
senescence. Explain why it would be
a waste of your money to buy it.
4. In some children, the ductus
arteriosus fails to close after birth—a
condition that eventually requires
surgery. Predict how this condition
would affect (a) pulmonary blood
pressure, (b) systemic diastolic
pressure, and (c) the right ventricle of
the heart.
5. Only one sperm is needed to fertilize
an egg, yet a man who ejaculates
fewer than 10 million sperm is
usually infertile. Explain this
apparent contradiction. Supposing 10
million sperm were ejaculated,
predict how many would come
within close range of the egg. How
likely is it that any one of these
sperm would fertilize it?
Answers at the Online Learning Center
Answers to Figure Legend Questions
29.2 An unfertilized egg dies long
before it reaches the uterus.

29.7 Eight weeks
29.12 Subcutaneous fat deposition
occurs largely in the eighth month.
29.14 XXY (Klinefelter syndrome) and
YO (a zygote that would not
survive)
29.16 Female, as seen from the two X
chromosomes at the lower right
www.mhhe.com/saladin3
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Saladin: Anatomy &
Physiology: The Unity of
Form and Function, Third
Edition
End Matter Appendix A Periodic Table
of Elements
© The McGraw−Hill
Companies, 2003
Nineteenth-century chemists discovered that when they
arranged the known elements by atomic weight, certain
properties reappeared periodically. In 1869, Russian
chemist Dmitri Mendeleev published the first modern
periodic table of the elements, leaving gaps for those that
had not yet been discovered. He accurately predicted
properties of the missing elements, which helped other
chemists discover and isolate them.
Each row in the table is a period and each column is a
group (family). Each period has one electron shell more
than the period above it, and as we progress from left to

right within a period, each element has one more proton
and electron than the one before. The dark steplike line
from boron (5) to astatine (85) separates the metals to the left
of it (except hydrogen) from the nonmetals to the right. Each
period begins with a soft, light, highly reactive alkali metal,
with one valence electron, in family IA. Progressing from
left to right, the metallic properties of the elements become
less and less pronounced. Elements in family VIIA are
highly reactive gases called halogens, with seven valence
electrons. Elements in family VIIIA, called noble (inert)
gases, have a full valence shell of eight electrons, which
makes them chemically unreactive. Ninety-one of the ele-
ments occur naturally on earth. Physicists have created ele-
ments up to atomic number 118 in the laboratory, but the
International Union of Pure and Applied Chemistry has
established formal names only through element 109 to date.
The 24 elements with normal roles in human physi-
ology are color-coded according to their relative abun-
dance in the body (see chapter 2). Others, however, may be
present as contaminants with very destructive effects
(such as arsenic, lead, and radiation poisoning).
Appendix A
Periodic Table of the Elements
A-1
1
Hydrogen
H
1.0079
IA
IIA

IIIB IVB VB VIB VIIB VIIIB IB IIB
IIIA IVA VA VIA VIIA
VIIIA
1
57–71, Lanthanides
Transition metals
89 –103, Actinides
2
3
4
Period
5
6
7
3
Lithium
Li
6.941
11
Sodium
Na
22.989
37
Rubidium
Rb
85.468
55
Cesium
Cs
132.905

87
Francium
Fr
(223)
4
Beryllium
Be
9.0122
12
Magnesium
Mg
24.305
20
Calcium
Ca
40.08
38
Strontium
Sr
87.62
56
Barium
Ba
137.34
88
Radium
Ra
(226)
21
Scandium

Sc
44.956
39
Yitrium
Y
88.905
22
Titanium
Ti
47.90
40
Zirconium
Zr
91.22
72
Hafnium
Hf
178.49
104
Rutherfordium
Rf
(261)
23
Vanadium
V
50.942
41
Niobium
Nb
92.906

73
Tantalum
Ta
180.948
105
Hahnium
Ha
(262)
24
Chromium
Cr
51.996
42
Molybdenum
Mo
95.94
74
Tungsten
W
183.85
106
Seaborgium
Sg
(263)
25
Manganese
Mn
54.938
43
Technetium

Tc
(99)
75
Rhenium
Re
186.2
107
Neilsbohrium
Ns
(261)
26
Iron
Fe
55.847
44
Ruthenium
Ru
101.07
76
Osmium
Os
190.2
108
Hassium
Hs
(265)
27
Cobalt
Co
58.933

45
Rhodium
Rh
102.905
77
Iridium
Ir
192.2
109
Meitnerium
Mt
(266)
28
Nickel
Ni
58.71
46
Palladium
Pd
106.4
78
Platinum
Pt
195.09
29
Copper
Cu
63.546
47
Silver

Ag
107.868
79
Gold
Au
196.967
30
Zinc
Zn
65.38
48
Cadmium
Cd
112.40
80
Mercury
Hg
200.59
5
Boron
B
10.811
13
Aluminum
Al
26.9815
31
Gallium
Ga
69.723

49
Indium
In
114.82
81
Thallium
Ti
204.37
6
Carbon
C
12.0112
14
Silicon
Si
28.086
32
Germanium
Ge
72.59
50
Tin
Sn
118.69
82
Lead
Pb
207.19
7
Nitrogen

N
14.0067
15
Phosphorus
P
30.9738
33
Arsenic
As
74.992
51
Antimony
Sb
121.75
83
Bismuth
Bi
208.980
60
Neodymium
Nd
144.24
59
Praseodymium
Pr
140.907
58
Cerium
Ce
140.12

57
Lanthanum
La
138.91
61
Promethium
Pm
144.913
62
Samarium
Sm
150.35
63
Europium
Eu
151.96
64
Gadolinium
Gd
157.25
65
Terbium
Tb
158.925
66
Dysprosium
Dy
162.50
67
Holmium

Ho
164.930
68
Erbium
Er
167.26
69
Thulium
Tm
168.934
70
Ytterbium
Yb
173.04
71
Lutetium
Lu
174.97
8
Oxygen
O
15.9994
16
Sulfur
S
32.064
34
Selenium
Se
78.96

52
Tellurium
Te
127.60
84
Polonium
Po
(209)
9
Fluorine
F
18.9984
17
Chlorine
Cl
35.453
35
Bromine
Br
79.904
53
Iodine
I
126.904
85
Astatine
At
(210)
2
Helium

He
4.0026
10
Neon
Ne
20.179
18
Argon
Ar
39.948
36
Krypton
Kr
83.80
54
Xenon
Xe
131.30
86
Radon
Rn
(222)
92
Uranium
U
238.03
91
Protactinium
Pa
(231)

90
Thorium
Th
232.038
89
Actinium
Ac
(227)
93
Neptunium
Np
(237)
94
Plutonium
Pu
244.064
95
Americium
Am
(243)
96
Curium
Cm
(247)
97
Berkelium
Bk
(247)
98
Californium

Cf
242.058
99
Einsteinium
Es
(254)
100
Fermium
Fm
257.095
101
Mendelevium
Md
258.10
102
Nobelium
No
259.10
103
Lawrencium
Lr
260.105
1
Hydrogen
H
1.0079
Key
98.5% (6 elements)
Percent of human
body (by weight)

Atomic number
Name
Symbol
Atomic mass
0.8% (6 elements)
0.7% (12 trace
elements)
19
Potassium
K
39.098
Saladin: Anatomy &
Physiology: The Unity of
Form and Function, Third
Edition
End Matter Appendix B Answers to
Chapter Review Questions
© The McGraw−Hill
Companies, 2003
Appendix B
Answers to Chapter Review Questions
A-2
This appendix provides answers to the end-of-chapter Testing
Your Recall and True/False questions. In the True or False sec-
tions, all statements are true except those listed and explained
here. Answers to the figure legend questions are given at the end
of each chapter; answers to Think About It and Testing Your
Comprehension questions are in the Instructor’s Manual; and
answers to Testing Your Comprehension are also given at the
Online Learning Center at www.mhhe.com/saladin3.

Chapter 1
1. a 8. c 15. homeostasis
2. e 9. d 16. set point
3. d 10. b 17. negative feedback
4. a 11. dissection 18. organ
5. c 12. Hooke 19. stereoscopic
6. c 13. deduction 20. prehensile,
7. a 14. psychosomatic opposable
True or False (explanation of the false statements only)
3. Auscultation means listening to body sounds, not inspecting its
appearance.
6. Leeuwenhoek was a textile merchant who built microscopes to
examine fabric.
7. A scientific theory is founded on a large body of evidence,
summarizing what is already known.
8. Both the treatment and control groups consist of volunteer
patients.
10. Negative feedback is a self-corrective process with a beneficial
effect on the body.
Atlas A
1. d 8. d 15. hand, foot
2. c 9. b 16. meninges
3. e 10. d 17. retroperitoneal
4. d 11. supine 18. medial
5. d 12. parietal 19. inferior
6. a 13. mediastinum 20. cubital, popliteal
7. a 14. nuchal
True or False (explanation of the false statements only)
4. The diaphragm is inferior to the lungs.
5. The esophagus is in the ventral body cavity.

6. The liver is in the hypochondriac region, superior to the lateral
abdominal region.
9. The peritoneum lines the outside of the stomach and intestines.
10. The sigmoid colon is in the lower left quadrant.
Chapter 2
1. a 8. c 14. anabolism
2. c 9. b 15. dehydration
3. a 10. d synthesis
4. c 11. cation 16. -ose, -ase
5. a 12. free radicals 17. phospholipids
6. e 13. catalyst, 18. cyclic adenosine
7. b enzymes monophosphate
19. anaerobic 20. substrate
fermentation
True or False (explanation of the false statements only)
1. The monomers of a polysaccharide are monosaccharides (simple
sugars).
3. Such molecules are called isomers, not isotopes.
6. A saturated fat is one to which no more hydrogen can be added.
8. Above a certain temperature, enzymes denature and cease
working.
9. These solutes have different molecular weights, so 2% solutions
would not contain the same amount of solute.
Chapter 3
1. e 9. d 16. exocytosis
2. b 10. b 17. nucleus,
3. d 11. micrometers mitochondria
4. b 12. second messenger 18. smooth ER,
5. e 13. voltage-regulated peroxisomes
6. e 14. hydrostatic 19. ligand-regulated

7. a pressure gate
8. c 15. hypertonic 20. cisterna
True or False (explanation of the false statements only)
1. Osmosis does not require ATP.
3. Second messengers activate enzymes in the cell; they are not
transport proteins.
5. A channel could not move material from the outside of a cell to
the inside unless it extended all the way across the membrane; it
must be an integral protein.
6. The plasma membrane consists primarily of phospholipid
molecules.
7. The brush border is composed of microvilli.
Chapter 4
1. a 8. d 15. RNA polymerased
2. e 9. d 16. chaperones
3. c 10. a 17. 46, 92, 92
4. c 11. cytokinesis 18. ribosome
5. e 12. alleles 19. growth factors
6. b 13. genetic code 20. autosomes
7. a 14. polyribosome
True or False (explanation of the false statements only)
1. There are no ribosomes on the Golgi complex; they are on the
rough ER.
2. There are no genes for steroids, carbohydrates, or phospholipids,
but only for proteins.
6. This law describes the pairing of bases between the two strands of
DNA, not between mRNA and tRNA.
9. Males have only one X chromosome, but have two sex
chromosomes (the X and Y).
10. Several RNA polymerase molecules at once can transcribe a gene.

Chapter 5
1. a 3. c 5. c
2. b 4. e 6. a
Saladin: Anatomy &
Physiology: The Unity of
Form and Function, Third
Edition
End Matter Appendix B Answers to
Chapter Review Questions
© The McGraw−Hill
Companies, 2003
Appendix B Answers to Chapter Review Questions A-3
7. b 13. lacunae 18. matrix
8. e 14. fibers (extracellular
9. b 15. collagen material)
10. b 16. skeletal muscle 19. proteoglycans
11. necrosis 17. basement 20. simple
12. mesothelium membrane
True or False (explanation of the false statements only)
1. The esophageal epithelium is nonkeratinized.
5. Adipose tissue is an exception; cells constitute most of its volume.
6. Adipocytes are also found in areolar tissue, either singly or in
small clusters.
7. Tight junctions serve mainly to restrict the passage of material
between cells.
10. Perichondrium is lacking from fibrocartilage and from hyaline
articular cartilage.
Chapter 6
1. d 9. a 16. earwax
2. c 10. d 17. sebaceous

3. d 11. insensible glands
4. b perspiration 18. anagen
5. a 12. piloerector 19. dermal
6. e 13. debridement papilla
7. c 14. cyanosis 20. third-degree
8. a 15. dermal papillae
True or False (explanation of the false statements only)
3. Keratin is the protein of the epidermis; the dermis is composed
mainly of collagen.
4. Vitamin D synthesis begins in the keratinocytes.
7. The hypodermis is not considered to be a layer of the skin.
8. Different races have about the same density of melanocytes but
different amounts of melanin.
9. A genetic lack of melanin causes albinism, not pallor. Pallor is a
temporary, nonhereditary paleness of the skin.
Chapter 7
1. e 8. e 15. hypocalcemia
2. a 9. b 16. osteoblasts
3. d 10. d 17. calcitriol
4. c 11. hydroxyapatite 18. osteoporosis
5. d 12. canaliculi 19. metaphysis
6. a 13. appositional 20. osteomalacia
7. d 14. solubility product
True or False (explanation of the false statements only)
3. The most common bone disease is osteoporosis, not fractures.
4. Bones elongate at the epiphyseal plate, not the articular cartilage.
5. Osteoclasts develop from stem cells in the bone marrow, not from
osteoblasts.
7. Hydroxyapatite is the major mineral of bone; the major protein is
collagen.

9. The major effect of vitamin D is bone resorption, though it also
promotes deposition.
Chapter 8
1. b 9. e 17. auricular
2. e 10. b 18. styloid
3. a 11. fontanels 19. pollex,
4. d 12. temporal hallux
5. a 13. sutures 20. medial
6. e 14. sphenoid longitudinal
7. c 15. annulus fibrosus
8. b 16. dens
True or False (explanation of the false statements only)
2. Each hand and foot has 14 phalanges.
3. The female pelvis is wider and shallower than the male’s.
7. The lumbar vertebrae have transverse processes but no transverse
costal facets.
8. The most frequently broken bone is the clavicle.
9. Arm refers to the region containing only the humerus; leg refers to
the region containing the tibia and fibula.
Chapter 9
1. c 8. d 15. gomphosis
2. b 9. b 16. serrate
3. a 10. d 17. extension
4. e 11. synovial fluid 18. range of motion
5. c 12. bursa 19. labrum
6. c 13. pivot 20. menisci
7. a 14. kinesiology
True or False (explanation of the false statements only)
1. Osteoarthritis occurs in almost everyone after a certain age;
rheumatoid arthritis is less common.

2. A kinesiologist studies joint movements; a rheumatologist treats
arthritis.
3. Synovial joints are diarthroses and amphiarthroses but never
synarthroses.
7. The round ligament is somewhat slack and probably does not
secure the femoral head.
9. Synovial fluid is secreted by the synovial membrane of the joint
capsule and fills the bursae.
Chapter 10
1. b 8. a 14. hamstring
2. e 9. d 15. flexor retinacula
3. a 10. c 16. urogenital triangle
4. c 11. origin 17. linea alba
5. e 12. fascicle 18. synergist
6. e 13. prime mover 19. bipennate
7. b (agonist) 20. sphincter
True or False (explanation of the false statements only)
3. The mastoid process is its insertion.
7. The trapezius is superficial to the scalenes.
8. Normal exhalation does not employ these muscles.
9. They result from rapid extension of the knee, not flexion.
10. They are on opposite sides of the tibia and act as antagonists.
Atlas B
1. f 11. y 21. k
2. b 12. m 22. d
3. k 13. n 23. f
4. p 14. e 24. b
5. h 15. g 25. a
6. z 16. v 26. u
7. o 17. f 27. j

8. x 18. c 28. i
9. c 19. y 29. g
10. a 20. x 30. q
Chapter 11
1. a 8. c 15. acetylcholine
2. d 9. e 16. myoglobin
3. b 10. b 17. Z discs
4. d 11. threshold 18. varicosities
5. a 12. complete tetanus 19. muscle tone
6. c 13. terminal cisternae 20. lactic acid
7. e 14. myosin
True or False (explanation of the false statements only)
1. A motor neuron may supply 1,000 or more muscle fibers; a motor
unit consists of one motor neuron and all the muscle fibers it
innervates.
2. Calcium binds to troponin, not to myosin.
Saladin: Anatomy &
Physiology: The Unity of
Form and Function, Third
Edition
End Matter Appendix B Answers to
Chapter Review Questions
© The McGraw−Hill
Companies, 2003
6. Thick and thin filaments are present but not arranged in a way
that produces striations.
7. Under natural conditions, a muscle seldom or never attains
complete tetanus.
9. A muscle produces most of its ATP during this time by anaerobic
fermentation, which generates lactic acid; it does not consume

lactic acid.
Chapter 12
1. e 9. d 15. oligodendrocytes
2. c 10. b 16. nodes of Ranvier
3. d 11. afferent 17. axon hillock,
4. a 12. conductivity initial segment
5. c 13. absolute 18. norepinephrine
6. e refractory period 19. facilitated zone
7. d 14. dendrites 20. neuromodulators
8. a
True or False (explanation of the false statements only)
4. The Na
ϩ
outflow depolarizes the neuron and the K
ϩ
inflow
repolarizes it.
5. The threshold stays the same but an EPSP brings the membrane
potential closer to the threshold.
7. The effect of a neurotransmitter varies from place to place
depending on the type of receptor present.
8. The signals travel rapidly through the internodes and slow down
at each node of Ranvier.
9. Synaptic contacts are remodeled, added, and removed throughout
life.
Chapter 13
1. e 8. a 15. intrafusal fibers
2. c 9. e 16. phrenic
3. d 10. b 17. decussation
4. d 11. ganglia 18. proprioception

5. e 12. ramus 19. dorsal root
6. c 13. spinocerebellar 20. tibial, common
7. c 14. crossed extensor fibular
True or False (explanation of the false statements only)
1. The gracile fasciculus is an ascending (sensory) tract.
4. All spinal nerves are mixed nerves; none are purely sensory or motor.
5. The dura is separated from the bone by a fat-filled epidural space.
8. Dermatomes overlap each other by as much as 50%.
9. Some somatic reflexes are mediated primarily through the
brainstem and cerebellum.
Chapter 14
1. c 8. d 14. hydrocephalus
2. a 9. e 15. choroid plexus
3. e 10. e 16. precentral
4. a 11. corpus callosum 17. frontal
5. b 12. ventricles, 18. association areas
6. c cerebrospinal 19. categorical
7. a 13. arbor vitae 20. Broca’s area
True or False (explanation of the false statements only)
1. This fissure separates the cerebral hemispheres, not the cerebellar
hemispheres.
2. The cerebral hemispheres do not develop from neural crest tissue.
5. The choroid plexuses produce only 30% of the CSF.
6. Hearing is a temporal lobe function; vision resides in the occipital
lobe.
10. Eye movements are controlled by the oculomotor, trochlear, and
abducens nerves; the optic nerve serves only to carry visual
information.
Chapter 15
1. b 8. d 15. enteric

2. c 9. a 16. norepinephrine
3. e 10. c 17. sympathetic
4. e 11. adrenergic 18. preganglionic,
5. a 12. dual innervation postganglionic
6. e 13. autonomic tone 19. cAMP
7. d 14. vagus 20. vasomotor tone
True or False (explanation of the false statements only)
1. Both systems are always simultaneously active.
3. In biofeedback and other circumstances, limited voluntary control
of the ANS is possible.
4. The sympathetic division inhibits digestion.
6. Waste elimination can occur by autonomic spinal reflexes without
necessarily involving the brain.
7. All parasympathetic fibers are cholinergic.
Chapter 16
1. a 8. c 15. hair cells
2. c 9. c 16. stapes
3. b 10. b 17. inferior colliculi
4. a 11. fovea centralis 18. taste hairs
5. e 12. ganglion 19. olfactory bulb
6. e 13. Na
ϩ
20. referred pain
7. d 14. otoliths
True or False (explanation of the false statements only)
1. These fibers end in the medulla oblongata.
3. Because of hemidecussation, the right hemisphere receives signals
from both eyes.
5. The posterior chamber, the space between iris and lens, is filled
with aqueous humor.

6. Descending analgesic fibers block signals that have reached the
dorsal horn of the spinal cord.
10. The trochlear and abducens nerves control the superior oblique
and lateral rectus, respectively.
Chapter 17
1. b 10. e 17. negative
2. d 11. adenohypophysis feedback
3. a 12. tyrosine inhibition
4. c 13. acromegaly 18. hypophyseal
5. c 14. cortisol portal system
6. c 15. glucocorticoids 19. permissive
7. d 16. granulosa, 20. up-regulation
8. c interstitial
9. e
True or False (explanation of the false statements only)
5. Hormones are also secreted by the heart, liver, kidneys, and other
organs not generally regarded as glands.
7. The pineal gland and thymus undergo involution with age.
8. Without iodine, there is no thyroid hormone (TH); without TH,
there can be no negative feedback inhibition.
9. The tissue at the center is the adrenal medulla.
10. There are also two testes, two ovaries, and four parathyroid
glands.
Chapter 18
1. b 6. d 11. hemopoiesis
2. c 7. d 12. hematocrit, or
3. c 8. c packed cell volume
4. a 9. d 13. thromboplastin
5. b 10. c 14. agglutinogens
A-4 Appendix B Answers to Chapter Review Questions

Saladin: Anatomy &
Physiology: The Unity of
Form and Function, Third
Edition
End Matter Appendix B Answers to
Chapter Review Questions
© The McGraw−Hill
Companies, 2003
Appendix B Answers to Chapter Review Questions A-5
15. hemophilia 18. polycythemia 20. erythropoietin
16. hemostasis 19. vitamin B
12
17. sickle-cell disease
True or False (explanation of the false statements only)
3. Oxygen deficiency is the result of anemia, not its cause.
4. Clotting is one mechanism of hemostasis, but hemostasis includes
others. Agglutination is unrelated to either of these.
6. The most abundant WBCs are neutrophils.
9. The heme is excreted; the globin is broken down into amino acids
that can be reused.
10. In leukemia, there is an excess of WBCs. A WBC deficiency is leukopenia.
Chapter 19
1. d 8. e 14. Na
ϩ
2. b 9. a 15. gap junctions
3. d 10. e 16. T wave
4. a 11. systole, diastole 17. semilunar
5. e 12. systemic 18. auscultation
6. c 13. atrioventricular 19. preload
7. d (coronary) sulcus 20. cardiac output

True or False (explanation of the false statements only)
1. The coronary circulation is part of the systemic circuit; the other
division is the pulmonary circuit.
3. The first two-thirds of ventricular filling occurs before the atria
contract. The atria add only about 31% of the blood that fills the
ventricles.
6. The first heart sound occurs at the time of the QRS complex.
7. The heart has its own internal pacemaker and would continue
beating; the nerves only alter the heart rate.
10. The ECG is a composite record of the electrical activity of the
entire myocardium, not a record from a single myocyte. It looks
much different from an action potential.
Chapter 20
1. c 8. a 14. thoracic pump
2. b 9. e 15. oncotic pressure
3. a 10. d 16. transcytosis
4. e 11. systolic, diastolic 17. sympathetic
5. b 12. continuous 18. baroreceptors
6. c capillaries 19. the arterial circle
7. e 13. anaphylactic 20. basilic, cephalic
True or False (explanation of the false statements only)
4. Some veins have valves, but arteries do not.
5. By the formula F ϰ r
4
, the flow increases 16-fold.
8. The capillaries normally reabsorb about 85% of the fluid they
filter; the rest is absorbed by the lymphatic system.
9. An aneurysm is a weak, bulging vessel which may rupture.
10. Anaphylactic shock is a form of venous pooling shock.
Chapter 21

1. b 9. a 15. opsonization
2. c 10. c 16. pyrogen
3. a 11. pathogen 17. interleukins
4. a 12. lysozyme 18. antigen-binding
5. d 13. lymphadenitis site, epitope
6. b 14. diapedesis 19. clonal deletion
7. e (emigration) 20. autoimmune
8. d
True or False (explanation of the false statements only)
1. Lysozyme is a bacteria-killing enzyme.
3. Interferons promote inflammation.
4. Helper T cells are also necessary to humoral immunity.
9. Anergy is a loss of lymphocyte activity, whereas autoimmune
diseases result from misdirected activity.
10. Interferons inhibit viral replication; perforins lyse bacteria.
Chapter 22
1. c 10. a 17. compliance,
2. c 11. glottis elasticity
3. a 12. bronchial tree 18. inspiratory
4. e 13. pulmonary surfactant center
5. e 14. intrapleural, 19. ventilation-
6. c atmospheric perfusion
7. b 15. obstructive coupling
8. a 16. anatomic dead 20. alkalosis,
9. d space hypocapnia
True or False (explanation of the false statements only)
1. The glottis is the superior opening into the larynx, not its inferior
exit.
4. When volume increases, pressure decreases.
5. Atelectasis can have other causes such as airway obstruction.

8. In an average 500 mL tidal volume, 350 mL reaches the alveoli.
10. Most CO
2
is transported as bicarbonate ion.
Chapter 23
1. a 9. c 16. transport
2. d 10. a maximum
3. b 11. micturition 17. antidiuretic
4. c 12. renal autoregulation hormone
5. b 13. trigone 18. internal urethral
6. b 14. macula densa 19. protein
7. d 15. podocytes 20. arcuate
8. e
True or False (explanation of the false statements only)
1. Parathyroid hormone regulates calcium absorption by the PCT.
2. Urine contains more urea and chloride than sodium.
4. A substantial amount of tubular fluid is reabsorbed by the
paracellular route, passing through leaky tight junctions.
5. Glycosuria does not occur in diabetes insipidus.
8. Urine can be as dilute as 50 mOsm/L.
Chapter 24
1. c 9. d 16. hyperkalemia
2. a 10. b 17. hyponatremia
3. a 11. Na
ϩ
18. respiratory
4. a 12. K
ϩ
acidosis
5. d 13. metabolic water 19. limiting pH

6. c 14. cutaneous 20. osmolarity
7. e transpiration
8. b 15. fluid sequestration
True or False (explanation of the false statements only)
2. Aldosterone has only a small influence on blood
pressure.
5. PTH promotes calcium absorption but phosphate excretion.
6. Protein buffers more acid than bicarbonate or phosphates do.
9. More water than salt is lost, so the body fluids become hypertonic.
10. Aquaporins are found in the distal tubule and collecting duct.
Chapter 25
1. b 4. e 7. a
2. d 5. a 8. a
3. c 6. c 9. a
Saladin: Anatomy &
Physiology: The Unity of
Form and Function, Third
Edition
End Matter Appendix B Answers to
Chapter Review Questions
© The McGraw−Hill
Companies, 2003
10. a 14. enteric 18. maltase, maltose
11. occlusal 15. vagus 19. chylomicrons
12. amylase, lipase 16. gastrin 20. iron
13. parotid 17. sinusoids
True or False (explanation of the false statements only)
1. Fat digestion begins in the stomach.
2. Most of the tooth is dentin.
3. Hepatocytes secrete bile into the bile canaliculi.

7. Intrinsic factor is involved in the absorption of vitamin B
12
.
10. Water, glucose, and other nutrients pass between cells, through the
tight junctions.
Chapter 26
1. a 8. a 15. liver
2. c 9. d 16. insulin
3. b 10. d 17. core temperature
4. e 11. incomplete 18. hypothalamus
5. b 12. glycogenolysis 19. cytochromes
6. e 13. gluconeogenesis 20. ATP synthase, ATP
7. c 14. urea
True or False (explanation of the false statements only)
1. Leptin suppresses the appetite.
4. Most of the cholesterol is endogenous, not dietary.
5. Excessive protein intake can cause renal damage.
8. Gluconeogenesis is a postabsorptive phenomenon.
9. Brown fat does not generate ATP.
Chapter 27
1. a 9. d 15. tunica albuginea
2. a 10. d 16. seminal vesicles
3. a 11. mesonephric 17. sustentacular
4. c 12. fructose 18. secondary
5. a 13. pampiniform spermatocyte
6. d plexus 19. deep
7. e 14. secondary 20. acrosome
8. c spermatocytes
True or False (explanation of the false statements only)
4. Only the testes are primary sex organs.

5. Female development results from a low testosterone level, not
from estrogen.
7. The pampiniform plexus prevents the testes from overheating.
8. Sperm are stored in the epididymis.
9. There is no such phenomenon as male menopause.
Chapter 28
1. a 8. b 15. corona radiata
2. d 9. c 16. antrum
3. c 10. c 17. climacteric
4. a 11. follicle 18. conceptus
5. e 12. endometrium 19. infundibulum,
6. b 13. menarche fimbriae
7. b 14. corpus luteum 20. lochia
True or False (explanation of the false statements only)
1. Only the ovum and corona radiata enter the uterine tube, not the
whole follicle.
2. HCG is secreted by the placenta.
5. Many eggs and follicles undergo atresia during childhood, so their
number is reduced by the age of puberty.
6. Prolactin is secreted during pregnancy but does not induce lactation
then.
10. Only the superficial layer (functionalis) is shed.
Chapter 29
1. b 8. a 15. chorionic villi
2. b 9. d 16. acrosome
3. c 10. d 17. collagen
4. c 11. teratogens 18. Down syndrome
5. a 12. nondisjunction (trisomy-21)
6. e 13. life span 19. foramen ovale
7. c 14. life expectancy 20. embryo

True or False (explanation of the false statements only)
1. Sperm require about 10 hours to become capacitated and able to
fertilize an egg.
2. Fertilization occurs in the uterine tube.
3. Several early-arriving sperm clear a path for the one that fertilizes
the egg.
8. Blood bypasses the lungs via the foramen ovale.
10. Exercise improves the quality of life in old age, but has not been
shown to increase life expectancy significantly.
A-6 Appendix B Answers to Chapter Review Questions
Saladin: Anatomy &
Physiology: The Unity of
Form and Function, Third
Edition
End Matter Appendix C Lexicon of
Biomedical Word Elements
© The McGraw−Hill
Companies, 2003
Appendix C
Lexicon of Biomedical Word Elements
a- no, not, without (atom, agranulocyte)
ab- away (abducens, abduction)
acetabulo- small cup (acetabulum)
acro- tip, extremity, peak (acromion,
acromegaly)
ad- to, toward, near (adsorption, adrenal)
adeno- gland (lymphadenitis,
adenohypophysis)
aero- air, oxygen (aerobic, anaerobe,
aerophagy)

af- toward (afferent)
ag- together (agglutination)
-al pertaining to (parietal, pharyngeal,
temporal)
ala- wing (ala nasi)
albi- white (albicans, linea alba, albino)
algi- pain (analgesic, myalgia)
aliment- nourishment (alimentary)
allo- other, different (allele, allosteric)
amphi- both, either (amphiphilic,
amphiarthrosis)
an- without (anaerobic, anemic)
ana- 1. up, build up (anabolic,
anaphylaxis). 2. apart (anaphase, anatomy).
3. back (anastomosis)
andro- male (androgen)
angi- vessel (angiogram, angioplasty,
hemangioma)
ante- before, in front (antebrachium)
antero- forward (anterior, anterograde)
anti- against (antidiuretic, antibody,
antagonist)
apo- from, off, away, above (apocrine,
aponeurosis)
arbor- tree (arboreal, arborization)
artic- 1. joint (articulation). 2. speech
(articulate)
-ary pertaining to (axillary, coronary)
-ase enzyme (polymerase, kinase, amylase)
ast-, astro- star (aster, astrocyte)

-ata, -ate 1. possessing (hamate, corniculate).
2. plural of -a (stomata, carcinomata)
athero- fat (atheroma, atherosclerosis)
atrio- entryway (atrium, atrioventricular)
auri- ear (auricle, binaural)
auto- self (autolysis, autoimmune)
axi- axis, straight line (axial, axoneme, axon)
baro- pressure (baroreceptor, hyperbaric)
bene- good, well (benign, beneficial)
bi- two (bipedal, biceps, bifid)
bili- bile (biliary, bilirubin)
bio- life, living (biology, biopsy, microbial)
blasto- precursor, bud, producer (fibroblast,
osteoblast, blastomere)
brachi- arm (brachium, brachialis,
antebrachium)
brady- slow (bradycardia, bradypnea)
bucco- cheek (buccal, buccinator)
burso- purse (bursa, bursitis)
calc- calcium, stone (calcaneus,
hypocalcemia)
callo- thick (callus, callosum)
calori- heat (calorie, calorimetry,
calorigenic)
calv-, calvari- bald, skull (calvaria)
calyx cup, vessel, chalice (glycocalyx, renal
calyx)
capito- head (capitis, capitate, capitulum)
capni- smoke, carbon dioxide (hypocapnia)
carcino- cancer (carcinogen, carcinoma)

cardi- heart (cardiac, cardiology,
pericardium)
carot- 1. carrot (carotene). 2. stupor
(carotid)
carpo- wrist (carpus, metacarpal)
case- cheese (caseosa, casein)
cata- down, break down (catabolism)
cauda- tail (cauda equina, caudate nucleus)
-cel little (pedicel)
celi- belly, abdomen (celiac)
centri- center, middle (centromere,
centriole)
cephalo- head (cephalic, encephalitis)
cervi- neck, narrow part (cervix, cervical)
chiasm- cross, X (optic chiasm)
choano- funnel (choana)
chole- bile (cholecystokinin,
cholelithotripsy)
chondro- 1. grain (mitochondria).
2. cartilage, gristle (chondrocyte,
perichondrium)
chromo- color (dichromat, chromatin,
cytochrome)
chrono- time (chronotropic, chronic)
cili- eyelash (cilium, supraciliary)
circ- about, around (circadian, circumduction)
cis- cut (incision, incisor)
cisterna reservoir (cisterna chyli)
clast- break down, destroy (osteoclast)
clavi- hammer, club, key (clavicle,

supraclavicular)
-cle little (tubercle, corpuscle)
cleido- clavicle (sternocleidomastoid)
cnemo- lower leg (gastrocnemius)
co- together (coenzyme, cotransport)
collo- 1. hill (colliculus). 2. glue (colloid,
collagen)
contra- opposite (contralateral)
corni- horn (cornified, corniculate, cornu)
corono- crown (coronary, corona, coronal)
corpo- body (corpus luteum, corpora
quadrigemina)
corti- bark, rind (cortex, cortical)
costa- rib (intercostal, subcostal)
coxa- hip (os coxae, coxal)
crani- helmet (cranium, epicranius)
cribri- sieve, strainer (cribriform, area
cribrosa)
crino- separate, secrete (holocrine,
endocrinology)
crista- crest (crista galli, mitochondrial
crista)
crito- to separate (hematocrit)
cruci- cross (cruciate ligament)
-cule, -culus small (canaliculus, trabecula,
auricular)
cune- wedge (cuneiform, cuneatus)
cutane-, cuti- skin (subcutaneous, cuticle)
cysto- bladder (cystitis, cholecystectomy)
cyto- cell (cytology, cytokinesis, monocyte)

de- down (defecate, deglutition,
dehydration)
demi- half (demifacet, demilune)
den-, denti- tooth (dentition, dens, dental)
dendro- tree, branch (dendrite,
oligodendrocyte)
derma-, dermato- skin (dermatology,
hypodermic)
desmo- band, bond, ligament (desmosome,
syndesmosis)
dia- 1. across, through, separate
(diaphragm, dialysis). 2. day (circadian)
dis- 1. apart (dissect, dissociate). 2. opposite,
absence (disinfect, disability)
diure- pass through, urinate (diuretic, diuresis)
dorsi- back (dorsal, dorsum, latissimus dorsi)
duc- to carry (duct, adduction, abducens)
dys- bad, abnormal, painful (dyspnea,
dystrophy)
e- out (ejaculate, eversion)
-eal pertaining to (hypophyseal, arboreal)
ec-, ecto- outside, out of, external (ectopic,
ectoderm, splenectomy)
ef- out of (efferent, effusion)
-el, -elle small (fontanel, organelle, micelle)
electro- electricity (electrocardiogram,
electrolyte)
em- in, within (embolism, embedded)
emesi-, emeti- vomiting (emetic,
hyperemesis)

-emia blood condition (anemia, hypoxemia)
en- in, into (enzyme, parenchyma)
encephalo- brain (encephalitis,
telencephalon)
enchymo- poured in (mesenchyme,
parenchyma)
endo- within, into, internal (endocrine,
endocytosis)
A-7
Saladin: Anatomy &
Physiology: The Unity of
Form and Function, Third
Edition
End Matter Appendix C Lexicon of
Biomedical Word Elements
© The McGraw−Hill
Companies, 2003
A-8 Appendix C Lexicon of Biomedical Word Elements
entero- gut, intestine (mesentery, myenteric)
epi- upon, above (epidermis, epiphysis,
epididymis)
ergo- work, energy, action (allergy, adrenergic)
eryth-, erythro- red (erythema, erythrocyte)
esthesio- sensation, feeling (anesthesia,
somesthetic)
eu- good, true, normal, easy (eupnea,
aneuploidy)
exo- out (exopeptidase, exocytosis, exocrine)
facili- easy (facilitated)
fasci- band, bundle (fascia, fascicle)

fenestr- window (fenestrated)
fer- to carry (efferent, uriniferous)
ferri- iron (ferritin, transferrin)
fibro- fiber (fibroblast, fibrosis)
fili- thread (myofilament, filiform)
flagello- whip (flagellum)
foli- leaf (folic acid, folia)
-form shape (cuneiform, fusiform)
fove- pit, depression (fovea)
funiculo- little rope, cord (funiculus)
fusi- 1. spindle (fusiform). 2. pour out
(perfusion)
gamo- marriage, union (monogamy, gamete)
gastro- belly, stomach (digastric,
gastrointestinal)
-gen, -genic, -genesis producing, giving rise
to (pathogen, carcinogenic, glycogenesis)
genio- chin (geniohyoid, genioglossus)
germi- 1. sprout, bud (germinal,
germinativum). 2. microbe (germicide)
gero- old age (progeria, geriatrics,
gerontology)
gesto- 1. to bear, carry (ingest). 2. pregnancy
(gestation, progesterone)
glia- glue (neuroglia, microglia)
globu- ball, sphere (globulin, hemoglobin)
glom- ball (glomerulus)
glosso- tongue (hypoglossal,
glossopharyngeal)
glyco- sugar (glycogen, glycolysis,

hypoglycemia)
gono- 1. angle, corner (trigone). 2. seed, sex
cell, generation (gonad, oogonium,
gonorrhea)
gradi- walk, step (retrograde, gradient)
-gram recording of (sonogram,
electrocardiogram)
-graph recording instrument (sonograph,
electrocardiograph)
-graphy recording process (sonography,
radiography)
gravi- severe, heavy (gravid, myasthenia
gravis)
gyro- turn, twist (gyrus)
hallu- great toe (hallux, hallucis)
hemi- half (hemidesmosome, hemisphere)
-hemia blood condition (polycythemia)
hemo- blood (hemophilia, hemoglobin,
hematology)
hetero- different, other, various
(heterozygous)
histo- tissue, web (histology, histone)
holo- whole, entire (holistic, holocrine)
homeo- constant, unchanging, uniform
(homeostasis, homeothermic)
homo- same, alike (homologous, homozygous)
hyalo- clear, glassy (hyaline, hyaluronic
acid)
hydro- water (dehydration, hydrolysis,
hydrophobic)

hyper- above, above normal, excessive
(hyperkalemia, hypertonic)
hypo- below, below normal, deficient
(hypogastric, hyponatremia, hypophysis)
-ia condition (anemia, hypocalcemia,
osteomalacia)
-ic pertaining to (isotonic, hemolytic,
antigenic)
-icle, -icul small (ossicle, canaliculus,
reticular)
ilia- flank, loin (ilium, iliac)
-illa, -illus little (bacillus)
-in protein (trypsin, fibrin, globulin)
infra- below (infraspinous, infrared)
ino- fiber (inotropic, inositol)
insulo- island (insula, insulin)
inter- between (intercellular, intervertebral)
intra- within (intracellular, intraocular)
iono- ion (ionotropic, cationic)
ischi- to hold back (ischium, ischemia)
-ism 1. process, state, condition
(metabolism, rheumatism). 2. doctrine,
belief, theory (holism, reductionism,
naturalism)
iso- same, equal (isometric, isotonic, isomer)
-issimus most, greatest (latissimus,
longissimus)
-ite little (dendrite, somite)
-itis inflammation (dermatitis, gingivitis)
jug- to join (conjugated, jugular)

juxta- next to (juxtamedullary,
juxtaglomerular)
kali- potassium (hypokalemia)
karyo- seed, nucleus (megakaryocyte,
karyotype)
kerato- horn (keratin, keratinocyte)
kine- motion, action (kinetic, kinase,
cytokinesis)
labi- lip (labium, levator labii)
lacera- torn, cut (foramen lacerum,
laceration)
lacrimo- tear, cry (lacrimal gland,
nasolacrimal)
lacto- milk (lactose, lactation, prolactin)
lamina- layer (lamina propria, laminar
flow)
latero- side (bilateral, ipsilateral)
lati- broad (fascia lata, latissimus dorsi)
-lemma husk (sarcolemma, neurilemma)
lenti- lens (lentiform)
-let small (platelet)
leuko- white (leukocyte, leukemia)
levato- to raise (levator labii, elevation)
ligo- to bind (ligand, ligament)
line- line (linea alba, linea nigra)
litho- stone (otolith, lithotripsy)
-logy study of (histology, physiology,
hematology)
lucid- light, clear (stratum lucidum, zona
pellucida)

lun- moon, crescent (lunate, lunule,
semilunar)
lute- yellow (macula lutea, corpus luteum)
lyso-, lyto- split apart, break down
(lysosome, hydrolysis, electrolyte,
hemolytic)
macro- large (macromolecule, macrophage)
macula- spot (macula lutea, macula densa)
mali- bad (malignant, malocclusion,
malformed)
malle- hammer (malleus, malleolus)
mammo- breast (mammary, mammillary)
mano- hand (manus, manipulate)
manubri- handle (manubrium)
masto- breast (mastoid, gynecomastia)
medi- middle (medial, mediastinum,
intermediate)
medullo- marrow, pith (medulla)
mega- large (megakaryocyte, hepatomegaly)
melano- black (melanin, melanocyte,
melancholy)
meno- month (menstruation, menopause)
mento- chin (mental, mentalis)
mero- part, segment (isomer, centromere,
merocrine)
meso- in the middle (mesoderm, mesentery)
meta- beyond, next in a series (metaphase,
metacarpal)
metabolo- change (metabolism, metabolite)
-meter measuring device (calorimeter,

spirometer)
metri- 1. length, measure (isometric,
emmetropic). 2. uterus (endometrium)
micro- small (microscopic, microcytic,
microglia)
mito- thread, filament, grain (mitochondria,
mitosis)
mono- one (monocyte, monogamy,
mononucleosis)
morpho- form, shape, structure
(morphology, amorphous)
muta- change (mutagen, mutation)
myelo- 1. spinal cord (poliomyelitis,
myelin). 2. bone marrow (myeloid,
myelocytic)
myo-, mysi- muscle (myoglobin, myosin,
epimysium)
natri- sodium (hyponatremia, natriuretic)
neo- new (neonatal, gluconeogenesis)
nephro- kidney (nephron, hydronephrosis)
neuro- nerve (aponeurosis, neurosoma,
neurology)
nucleo- nucleus, kernel (nucleolus, nucleic
acid)
oo- egg (oogenesis, oocyte)
ob- 1. life (aerobic, microbe). 2. against,
toward, before (obstetrics, obturator,
obstruction)
oculo- eye (oculi, oculomotor)
odonto- tooth (odontoblast, periodontal)

-oid like, resembling (colloid, sigmoid,
ameboid)
-ole small (arteriole, bronchiole, nucleolus)
oligo- few, a little, scanty (oligopeptide,
oliguria)
-oma tumor, mass (carcinoma, hematoma)
omo- shoulder (omohyoid, acromion)
onycho- nail, claw (hyponychium,
onychomycosis)
Saladin: Anatomy &
Physiology: The Unity of
Form and Function, Third
Edition
End Matter Appendix C Lexicon of
Biomedical Word Elements
© The McGraw−Hill
Companies, 2003
Appendix C Lexicon of Biomedical Word Elements A-9
op- vision (optics, myopia, photopic)
-opsy viewing, to see (biopsy, rhodopsin)
or- mouth (oral, orbicularis oris)
orbi- circle (orbicularis, orbit)
organo- tool, instrument (organ, organelle)
ortho- straight (orthopnea, orthodontics,
orthopedics)
-ose 1. full of (adipose). 2. sugar (sucrose,
glucose)
-osis 1. process (osmosis, exocytosis).
2. condition, disease (cyanosis, thrombosis).
3. increase (leukocytosis)

osmo- push (osmosis, chemiosmotic)
osse-, oste- bone (osseous, osteoporosis)
oto- ear (otolith, otitis, parotid)
-ous 1. full of (nitrogenous, edematous).
2. pertaining to (mucous, nervous). 3. like,
characterized by (squamous, filamentous)
ovo- egg (ovum, ovary, ovulation)
oxy- 1. oxygen (hypoxia, oxyhemoglobin).
2. sharp, quick (oxytocin)
palli- pale (pallor, globus pallidus)
palpebro- eyelid (palpebrae)
pan- all (panhypopituitarism, pancreas)
panni- cloth, rag (pannus, panniculus)
papillo- nipple (papilla, papillary)
par- birth (postpartum, parturition,
multiparous)
para- next to (parathyroid, parotid)
parieto- wall (parietal)
patho- 1. disease (pathology, pathogen).
2. feeling (sympathetic)
pecto- 1. chest (pectoralis). 2. comblike
(pectineus)
pedi- 1. foot (bipedal, pedicle). 2. child
(pediatrics)
pelvi- basin (pelvis, pelvic)
-penia deficiency (leukopenia,
thrombocytopenia)
penna- feather (unipennate, bipennate)
peri- around (periosteum, peritoneum,
periodontal)

perone- fibula (peroneus tertius, peroneal
nerve)
phago- eat (phagocytosis, macrophage)
philo- loving, attracted to (hydrophilic,
amphiphilic)
phobo- fearing, repelled by (hydrophobic)
phor- to carry, bear (diaphoresis,
electrophoresis)
phragm- partition (diaphragm)
phreno- diaphragm (phrenic nerve)
physio- nature, natural cause (physiology,
physician)
-physis growth (diaphysis, hypophysis)
pilo- hair (piloerection)
pino- drink, imbibe (pinocytosis)
planto- sole of foot (plantaris, plantar wart)
plasi- growth (hyperplasia)
plasm- shaped, molded (cytoplasm,
endoplasmic)
plasti- form (thromboplastin)
platy- flat (platysma)
pnea- breath, breathing (eupnea, dyspnea)
pneumo- air, breath, lung (pneumonia,
pneumothorax)
podo- foot (pseudopod, podocyte)
poies- forming (hemopoiesis,
erythropoietin)
poly- many, much, excessive (polypeptide,
polyuria)
primi- first (primary, primipara, primitive)

pro- 1. before, in front, first (prokaryote,
prophase, prostate). 2. promote, favor
(progesterone, prolactin)
pseudo- false (pseudopod)
psycho- mind (psychosis, psychosomatic)
ptero-, pterygo- wing (pterygoid)
-ptosis dropping, falling, sagging
(apoptosis, nephroptosis)
puncto- point (puncta)
pyro- fire (pyrogen, antipyretic)
quadri- four (quadriceps, quadratus)
quater- fourth (quaternary)
radiat- radiating (corona radiata)
rami- branch (ramus)
recto- straight (rectus abdominis, rectum)
reno- kidney (renal, renin)
reti- network (reticular, rete testis)
retinac- retainer, bracelet (retinaculum)
retro- behind, backward (retroperitoneal,
retrovirus)
rhombo- rhombus (rhomboideus,
rhombencephalon)
rubo-, rubro- red (bilirubin, rubrospinal)
rugo- fold, wrinkle (ruga, corrugator)
sacculo- little sac (saccule)
sarco- flesh, muscle (sarcoplasm,
sarcomere)
scala- staircase (scala tympani)
sclero- hard, tough (sclera, sclerosis)
scopo- see (microscope, endoscopy)

secto- cut (section, dissection)
semi- half (semilunar, semimembranosus)
sepsi- infection (asepsis, septicemia)
-sis process (diapedesis, amniocentesis)
sole- sandal, sole of foot, flatfish (sole, soleus)
soma-, somato- body (somatic,
somatotropin)
spheno- wedge (sphenoid)
spiro- breathing (inspiration, spirometry)
splanchno- viscera (splanchnic)
spleno- 1. bandage (splenius capitis). 2.
spleen (splenic artery)
squamo- scale, flat (squamous,
desquamation)
stasi-, stati- put, remain, stay the same
(hemostasis, homeostatic)
steno- narrow (stenosis)
ster-, stereo- solid, three-dimensional
(steroid, stereoscopic)
sterno- breast, chest (sternum,
sternocleidomastoid)
stria- stripe (striated, corpus striatum)
sub- below (subcutaneous, subclavicular)
sulc- furrow, groove (sulcus)
supra- above (supraspinous, supraclavicular)
sura- calf of leg (triceps surae)
sym- together (sympathetic, symphysis)
syn- together (synostosis, syncytium)
tachy- fast (tachycardia, tachypnea)
tarsi- ankle (tarsus, metatarsal)

tecto- roof, cover (tectorial membrane,
tectum)
telo- last, end (telophase, telencephalon,
telodendria)
tempo- time (temporal)
terti- third (tertiary)
theli- nipple, female, tender (epithelium,
polythelia)
thermo- heat (thermogenesis,
thermoregulation)
thrombo- blood clot (thrombosis, thrombin)
thyro- shield (thyroid, thyrohyoid)
-tion process (circulation, pronation)
toci- birth (oxytocin)
tomo- 1. cut (tomography, atom, anatomy).
2. segment (dermatome, myotome,
sclerotome)
tono- force, tension (isotonic, tonus,
myotonia)
topo- place, position (isotope, ectopic)
trabo- plate (trabecula)
trans- across (transpiration, transdermal)
trapezi- 1. table, grinding surface
(trapezium). 2. trapezoid (trapezius)
tri- three (triceps, triglyceride)
tricho- hair (trichosiderin, peritrichial)
trocho- wheel, pulley (trochlea)
troph- 1. food, nourishment (trophic,
trophoblast). 2. growth (dystrophy,
hypertrophy)

tropo- to turn, change (metabotropic,
gonadotropin)
tunica- coat (tunica intima, tunica
vaginalis)
tympano- drum, eardrum (tympanic, tensor
tympani)
-ul small (trabecula, tubule, capitulum,
glomerulus)
-uncle, -unculus small (homunculus,
caruncle)
uni- one (unipennate, unipolar)
uri- urine (glycosuria, urinalysis, diuretic)
utriculo- little bag (utriculus)
vagino- sheath (invaginate, tunica
vaginalis)
vago- wander (vagus)
vaso- vessel (vascular, vas deferens, vasa
recta)
ventro- belly, lower part (ventral, ventricle)
vermi- worm (vermis, vermiform appendix)
vertebro- spine (vertebrae, intervertebral)
vesico- bladder, blister (vesical, vesicular)
villo- hair, hairy (microvillus)
vitre- glass (in vitro, vitreous humor)
vivi- life, alive (in vivo, revive)
zygo- union, join, mate (zygomatic, zygote,
azygos)
Saladin: Anatomy &
Physiology: The Unity of
Form and Function, Third

Edition
End Matter Glossary
© The McGraw−Hill
Companies, 2003
G-1
Glossary
This glossary defines approximately
1,000 terms. They are not necessarily the
most important ones in the book, but
they are terms that are reintroduced most
often and, for lack of space, are not
redefined each time they arise. The index
indicates where you can find definitions
or explanations of additional terms.
Terms are defined only in the sense that
they are used in this book. Some have
broader meanings, even within biology
and medicine, that are beyond its scope.
Terms that are commonly abbreviated,
such as ATP and PET scan, are defined
under the full spelling. See the list of
abbreviations inside the front cover for
complete spellings. The glossary gives
pronunciation guides for many terms,
with accented syllables in capital letters.
A key to the pronunciation of individual
syllables and letter groups can be found
at the end of the glossary.
A
abdominal cavity The body cavity between the

diaphragm and pelvic brim. fig. A.7
abduction (ab-DUC-shun) Movement of a body
part away from the median plane, as in raising an
arm away from the side of the body. fig. 9.10
absorption 1. Process in which a chemical passes
through a membrane or tissue surface and
becomes incorporated into a body fluid or tissue.
2. Any process in which one substance passes into
another and becomes a part of it. Compare
adsorption.
acetate The ionized form of acetic acid (CH
3
COO
Ϫ
).
Serves as the monomer of fatty acids and the
intermediate of aerobic metabolism that enters
the citric acid cycle.
acetylcholine (ACh) (ASS-eh-till-CO-leen) A neuro-
transmitter released by somatic motor fibers,
parasympathetic fibers, and some other neurons,
composed of choline and an acetyl group. fig.
12.18
acetylcholinesterase (AChE) (ASS-eh-till-CO-lin-
ESS-ter-ase) An enzyme that hydrolyzes acetyl-
choline, thus halting signal transmission at a
cholinergic synapse.
acid A proton (H
ϩ
) donor; a chemical that releases

protons into solution.
acidosis An acid-base imbalance in which the blood
pH is lower than 7.35.
acinus (ASS-ih-nus) A sac of secretory cells at the
inner end of a gland duct. fig. 5.30
acquired immunodeficiency syndrome (AIDS) A
group of conditions that indicate severe immuno-
suppression related to infection with the human
immunodeficiency virus (HIV); typically character-
ized by a very low T
4
lymphocyte count and high
susceptibility to certain forms of cancer and
opportunistic infections.
actin A filamentous intracellular protein that provides
cytoskeletal support and interacts with other pro-
teins, especially myosin, to cause cellular move-
ment; important in muscle contraction, ciliary and
flagellar beating, and membrane actions such as
phagocytosis, ameboid movement, and cytokinesis.
action The movement produced by the contraction
of a particular muscle.
action potential A rapid voltage change in which a
plasma membrane briefly reverses electrical
polarity; has a self-propagating effect that pro-
duces a traveling wave of excitation in nerve and
muscle cells.
active site The region of a protein that binds to a
ligand, such as the substrate-binding site of an
enzyme or the hormone-binding site of a receptor.

active transport The movement of a solute through
a cellular membrane, against its concentration gra-
dient, involving a carrier protein that expends ATP.
acute Pertaining to a disease with abrupt onset,
intense symptoms, and short duration. Compare
chronic.
adaptation 1. An evolutionary process leading to
the establishment of species characteristics that
favor survival and reproduction. 2. Any character-
istic of anatomy, physiology, or behavior that pro-
motes survival and reproduction. 3. A sensory
process in which a receptor adjusts its sensitivity
or response to the prevailing level of stimulation,
such as dark adaptation of the eye.
adduction (ah-DUC-shun) Movement of a body
part toward the median plane, such as bringing
the feet together from a spread-legged position.
fig. 9.10
adenine (AD-eh-neen) A double-ringed nitrogenous
base (purine) found in such molecules as DNA,
RNA, and ATP; one of the four bases of the
genetic code; complementary to thymine in the
double helix of DNA. fig. 4.2
adenosine triphosphate (ATP) (ah-DEN-oh-seen
tri-FOSS-fate) A molecule composed of adenine,
ribose, and three phosphate groups that functions
as a universal energy-transfer molecule; yields
adenosine diphosphate (ADP) and an inorganic
phosphate group (P
i

) upon hydrolysis. fig. 2.29a
adenylate cyclase (ah-DEN-ih-late SY-clase) An
enzyme of the plasma membrane that removes
two phosphate molecules from ATP and makes
cyclic adenosine monophosphate (cAMP); impor-
tant in the activation of the cAMP second-mes-
senger system.
adipocyte (AD-ih-po-site) A fat cell.
adipose tissue A connective tissue composed pre-
dominantly of adipocytes; fat.
adrenal gland (ah-DREE-nul) An endocrine gland
on the superior pole of each kidney. fig. 17.10
adrenergic (AD-reh-NUR-jic) Pertaining to epi-
nephrine (adrenaline) or norepinephrine (nora-
drenaline), as in adrenergic neurons that secrete
one of these chemicals or adrenergic effects on a
target organ.
adrenocorticotropic hormone (ACTH) (ah-DREE-
no-COR-tih-co-TRO-pic) A hormone secreted by
the anterior pituitary gland that stimulates the
adrenal cortex.
adsorption The binding of one substance to the
surface of another without becoming a part of
the latter. Compare absorption.
adventitia (AD-ven-TISH-uh) Loose connective tis-
sue forming the outermost sheath around organs
such as a blood vessel or the esophagus.
aerobic exercise (air-OH-bic) Exercise in which oxy-
gen is used to produce ATP; endurance exercise.
aerobic respiration Oxidation of organic com-

pounds in a reaction series that requires oxygen
and produces ATP.
afferent (AFF-uh-rent) Carrying toward, as in affer-
ent neurons, which carry signals toward the cen-
tral nervous system, and afferent arterioles,
which carry blood toward a tissue. Compare
efferent.
afterload The force exerted by arterial blood pres-
sure that opposes the openings of the aortic and
pulmonary valves of the heart.
agglutination (ah-GLUE-tih-NAY-shun) Clumping
of cells or molecules by antibodies. fig. 18.15
aging Any changes in the body that occur with the
passage of time, including growth, development,
and senescence.
agonist See prime mover.
agranulocyte Either of the two leukocyte types
(lymphocytes and monocytes) that lack prominent
cytoplasmic granules.
albumin (al-BYU-min) A class of small proteins
constituting about 60% of the protein fraction of
the blood plasma; plays roles in blood viscosity,
colloid osmotic pressure, and solute transport.
aldosterone (AL-doe-steh-RONE, al-DOSS-teh-
rone) A steroid hormone secreted by the adrenal
cortex that acts on the kidneys to promote
sodium retention and potassium excretion.
alkalosis An acid-base imbalance in which the
blood pH is higher than 7.45.
Saladin: Anatomy &

Physiology: The Unity of
Form and Function, Third
Edition
End Matter Glossary
© The McGraw−Hill
Companies, 2003
Glossary G-2
allele (ah-LEEL) Any of the alternative forms that
one gene can take, such as dominant and reces-
sive alleles.
all-or-none law The statement that a neuron either
produces an action potential of maximum
strength if it is depolarized to or above threshold,
or produces no action potential at all if the stimu-
lus is not strong enough to reach threshold; there
are no action potentials of intermediate strength.
alveolus (AL-vee-OH-lus) 1. A microscopic air sac of
the lung. 2. A gland acinus. 3. A tooth socket. 4.
Any small anatomical space.
Alzheimer disease (AD) (ALTS-hy-mur) A degenera-
tive disease of the senescent brain, typically
beginning with memory lapses and progressing to
severe losses of mental and motor functions and
ultimately death.
ameboid movement (ah-ME-boyd) Movement of a
cell by means of pseudopods, in a manner similar
to that of an ameba; seen in leukocytes and some
macrophages.
amino acids Small organic molecules with an
amino group and a carboxyl group; the

monomers of which proteins are composed.
amino group A functional group with the formula
–NH
2
, found in amino acids and some other
organic molecules.
ampulla (am-PULL-uh) A wide or saclike portion of
a tubular organ such as a semicircular duct or
uterine tube.
anabolism (ah-NAB-oh-lizm) Any metabolic reac-
tions that consume energy and construct more
complex molecules with higher free energy from
less complex molecules with lower free energy;
for example, the synthesis of proteins from amino
acids. Compare catabolism.
anaerobic fermentation (AN-err-OH-bic) A reduc-
tion reaction independent of oxygen that con-
verts pyruvic acid to lactic acid and enables gly-
colysis to continue under anaerobic conditions.
anaphylactic shock A severe systemic form of ana-
phylaxis involving bronchoconstriction, impaired
breathing, vasodilation, and a rapid drop in blood
pressure with a threat of circulatory failure.
anaphylaxis (AN-uh-fih-LAC-sis) A form of immediate
hypersensitivity in which an antigen triggers the
release of inflammatory chemicals, causing edema,
congestion, hives, and other, usually local, signs.
anastomosis (ah-NASS-tih-MO-sis) An anatomical
convergence, the opposite of a branch; a point
where two blood vessels merge and combine their

bloodstreams or where two nerves or ducts con-
verge. fig. 20.1
anatomical position A reference posture that
allows for standardized anatomical terminology. A
subject in anatomical position is standing with
the feet flat on the floor, arms down to the sides,
and the palms and eyes directed forward. fig. A.1
anatomy 1. Structure of the body. 2. The study of
structure.
androgen (AN-dro-jen) Testosterone or a related
steroid hormone. Stimulates somatic changes at
puberty in both sexes, adult libido in both sexes,
development of male anatomy in the fetus and
adolescent, and spermatogenesis.
anemia (ah-NEE-me-uh) A deficiency of erythro-
cytes or hemoglobin.
aneurysm (AN-you-rizm) A weak, bulging point in
the wall of a heart chamber or blood vessel that
presents a threat of hemorrhage.
angiogenesis (AN-jee-oh-GEN-eh-sis) The growth
of new blood vessels.
angiotensin II (AN-jee-oh-TEN-sin) A hormone pro-
duced from angiotensinogen (a plasma protein)
by the kidneys and lungs; raises blood pressure by
stimulating vasoconstriction and stimulating the
adrenal cortex to secrete aldosterone.
anion (AN-eye-on) An ion with more electrons than
protons and consequently a net negative charge.
antagonist 1. A muscle that opposes the agonist at
a joint. 2. Any agent, such as a hormone or drug,

that opposes another.
antebrachium (AN-teh-BRAY-kee-um) The region
from elbow to wrist; the forearm.
anterior Pertaining to the front (facial-abdominal
aspect) of the body; ventral.
antibody A protein of the gamma globulin class
that reacts with an antigen; found in the blood
plasma, in other body fluids, and on the surfaces
of certain leukocytes and their derivatives.
anticoagulant (AN-tee-co-AG-you-lent) A chemi-
cal agent that opposes blood clotting.
antidiuretic hormone (ADH) (AN-tee-DYE-you-RET-
ic) A hormone released by the posterior lobe of
the pituitary gland in response to low blood pres-
sure; promotes water retention by the kidneys.
Also known as vasopressin.
antigen (AN-tih-jen) Any large molecule capable of
binding to an antibody and triggering an immune
response.
antigen-presenting cell (APC) A cell that phagocy-
tizes an antigen and displays fragments of it on its
surface for recognition by other cells of the
immune system; chiefly macrophages and B lym-
phocytes.
antioxidant A chemical that binds and neutralizes
free radicals, minimizing their oxidative damage
to a cell; for example, selenium and vitamin E.
antiport A cotransport protein that moves two or
more solutes in opposite directions through a cel-
lular membrane; for example, the Na

ϩ
-K
ϩ
pump.
aorta A large artery that extends from the left ventri-
cle to the lower abdominal cavity and gives rise to all
other arteries of the systemic circulation. fig. 20.21
apical surface The uppermost surface of an epithe-
lial cell, usually exposed to the lumen of an
organ. fig. 3.5
apocrine Pertaining to certain sweat glands with
large lumens and relatively thick, aromatic secre-
tions and to similar glands such as the mammary
gland; formerly thought to form secretions by
pinching off bits of apical cytoplasm.
apoptosis (AP-oh-TOE-sis) Programmed cell death;
the normal death of cells that have completed
their function. Compare necrosis.
appendicular (AP-en-DIC-you-lur) Pertaining to
the extremities and their supporting skeletal gir-
dles. fig. 8.1
arcuate (AR-cue-et) Making a sharp L- or U-shaped
bend (arc), as in the arcuate arteries of the kid-
neys and uterus.
areolar tissue (AIR-ee-OH-lur) A fibrous connective
tissue with loosely organized, widely spaced fibers
and cells and an abundance of fluid-filled space;
found under nearly every epithelium, among
other places. fig. 5.15
arrhythmia (ah-RITH-me-uh) An irregularity in the

cardiac rhythm.
arteriole (ar-TEER-ee-ole) A small artery that emp-
ties into a metarteriole or capillary.
artery Any blood vessel that conducts blood away
from the heart.
articular cartilage A thin layer of hyaline cartilage
covering the articular surface of a bone at a syn-
ovial joint serving to reduce friction and ease
joint movement. fig. 9.6
articulation A skeletal joint; any point at which
two bones meet; may or may not be movable.
ascorbic acid Vitamin C; a dietary antioxidant.
aspect A particular view of the body or one of its
structures, or a part that faces in a particular
direction, such as the anterior aspect.
atheroma (ATH-ur-OH-muh) A fatty deposit
(plaque) in a blood vessel consisting of lipid,
smooth muscle, and macrophages; characteristic
of atherosclerosis. fig. 19.21
atherosclerosis (ATH-ur-oh-skleh-ROE-sis) A
degenerative disease of the blood vessels charac-
terized by the presence of atheromas and often
leading to calcification of the vessel wall.
atrial natriuretic peptide (ANP) (AY-tree-ul NAY-
tree-you-RET-ic) A hormone secreted by the heart
that lowers blood pressure by promoting sodium
excretion and antagonizing aldosterone.
atrioventricular (AV) node (AY-tree-oh-ven-TRIC-
you-lur) A group of autorhythmic cells in the
interatrial septum of the heart that relays excita-

tion from the atria to the ventricles.
atrioventricular (AV) valves The bicuspid (right)
and tricuspid (left) valves between the atria and
ventricles of the heart.
atrophy (AT-ro-fee) Shrinkage of a tissue due to
age, disuse, or disease.
auditory ossicles Three small middle-ear bones that
transfer vibrations from the tympanic membrane
to the inner ear; the malleus, incus, and stapes.
autoantibody An antibody that fails to distinguish
the body’s own molecules from foreign molecules
and thus attacks host tissues, causing autoim-
mune diseases.
autoimmune disease Any disease in which antibodies
fail to distinguish between foreign and self-antigens
and attack the body’s own tissues; for example, sys-
temic lupus erythematosus and rheumatic fever.
autolysis (aw-TOLL-ih-sis) Digestion of cells by their
own internal enzymes.
autonomic nervous system (ANS) (AW-toe-NOM-
ic) A motor division of the nervous system that
innervates glands, smooth muscle, and cardiac
muscle; consists of sympathetic and parasympa-
thetic divisions and functions largely without vol-
untary control. Compare somatic nervous system.
autoregulation The ability of a tissue to adjust its
own blood supply through vasomotion or angio-
genesis.
autorhythmic (AW-toe-RITH-mic) Pertaining to
cells that spontaneously produce action poten-

tials at regular time intervals, chiefly cardiac and
smooth muscle cells.
autosome (AW-toe-some) Any chromosome except
the sex chromosomes. Genes on the autosomes
Saladin: Anatomy &
Physiology: The Unity of
Form and Function, Third
Edition
End Matter Glossary
© The McGraw−Hill
Companies, 2003
G-3 Glossary
are inherited without regard to the sex of the
individual.
axial (AC-see-ul) Pertaining to the head, neck, and
trunk; the part of the body excluding the appen-
dicular portion. fig. 8.1
axillary (ACK-sih-LERR-ee) Pertaining to the armpit.
axon A process of a neuron that transmits action
potentials; also called a nerve fiber. There is only
one axon to a neuron, and it is usually much
longer and much less branched than the den-
drites. fig. 12.4
axoneme (AC-so-neem) The core of microtubules,
usually in a “9 ϩ 2” array, at the center of a cil-
ium or flagellum. fig. 3.11
B
baroreceptors (BAR-oh-re-SEP-turz) Pressure sen-
sors located in the heart, aortic arch, and carotid
sinuses that trigger autonomic reflexes in

response to fluctuations in blood pressure.
basal metabolic rate (BMR) The rate of energy
consumption of a person who is awake, relaxed,
at a comfortable temperature, and has not eaten
for 12 to 14 hours; usually expressed as kilocalo-
ries per square meter of body surface per hour.
Compare metabolic rate.
basal nuclei Masses of deep cerebral gray matter
that play a role in the coordination of posture
and movement. fig. 14.16
base 1. A chemical that binds protons from solution;
a proton acceptor. 2. Any of the purines or pyrim-
idines of a nucleic acid (adenine, thymine, guanine,
cytosine, or uracil), serving in part to code for pro-
tein structure. 3. The broadest part of a tapered
organ such as the uterus or the inferior aspect of
an organ such as the brain.
basement membrane A thin layer of glycoproteins,
collagen, and glycosaminoglycans beneath the
deepest cells of an epithelium, serving to bind the
epithelium to the underlying tissue. fig. 5.33
base triplet A sequence of three DNA nucleotides
that codes indirectly (through mRNA) for one
amino acid of a protein.
basophil (BAY-so-fill) A granulocyte with coarse
cytoplasmic granules that produces heparin, his-
tamine, and other chemicals involved in inflam-
mation. table 18.8
belly The thick part of a skeletal muscle between its
origin and insertion. fig. 10.2

bicarbonate buffer system An equilibrium mixture
of carbonic acid, bicarbonate ions, and hydrogen
ions (H
2
CO
3
↔ HCO
3
Ϫ
ϩ H
ϩ
) that stabilizes the
pH of the body fluids.
bicarbonate ion An anion, HCO
3
Ϫ
, that functions
as a base in the buffering of body fluids.
bile A secretion produced by the liver, concentrated and
stored in the gallbladder, and released into the small
intestine; consists mainly of wastes such as excess
cholesterol, salts, and bile pigments but also contains
lecithin and bile acids, which aid in fat digestion.
bile pigments Strongly colored organic compounds
produced by the breakdown of hemoglobin,
including biliverdin and bilirubin.
bilirubin (BIL-ih-ROO-bin) A yellow to orange bile
pigment produced by the breakdown of hemoglobin
and excreted in the bile; causes jaundice and neuro-
toxic effects if present in excessive concentration.

biogenic amines A class of chemical messengers
with neurotransmitter and hormonal functions,
synthesized from amino acids and retaining an
amino group; also called monoamines. Examples
include epinephrine and thyroxine.
bipedalism The habit of walking on two legs; a
defining characteristic of the family Hominidae
that underlies many skeletal and other character-
istics of humans.
blood-brain barrier (BBB) A barrier between the
bloodstream and nervous tissue of the brain that is
impermeable to many blood solutes and thus pre-
vents them from affecting the brain tissue; formed
by the tight junctions between capillary endothe-
lial cells, the basement membrane of the endothe-
lium, and the perivascular feet of astrocytes.
B lymphocyte A lymphocyte that functions as an
antigen-presenting cell and, in humoral immu-
nity, differentiates into an antibody-producing
plasma cell; also called a B cell.
body 1. The entire organism. 2. Part of a cell, such
as a neuron, containing the nucleus and most
other organelles. 3. The largest or principal part
of an organ such as the stomach or uterus; also
called the corpus.
bolus A mass of matter, especially food or feces
traveling through the digestive tract.
bone 1. A calcified connective tissue; also called
osseous tissue. 2. An organ of the skeleton com-
posed of osseous tissue, fibrous connective tissue,

marrow, cartilage, and other tissues.
Bowman’s capsule See glomerular capsule.
brachial (BRAY-kee-ul) Pertaining to the arm
proper, the region from shoulder to elbow.
bradykinin (BRAD-ee-KY-nin) An oligopeptide pro-
duced in inflammation that stimulates vasodila-
tion, increases capillary permeability, and stimu-
lates pain receptors.
brainstem The stalklike lower portion of the brain,
composed of all of the brain except the cerebrum
and cerebellum. (Many authorities also exclude the
diencephalon and regard only the medulla oblon-
gata, pons, and midbrain as the brainstem.) fig.
14.8
bronchiole (BRONK-ee-ole) A pulmonary air pas-
sage that is usually 1 mm or less in diameter and
lacks cartilage but has relatively abundant
smooth muscle, elastic tissue, and a simple
cuboidal, usually ciliated epithelium.
bronchus (BRONK-us) A relatively large pulmonary
air passage with supportive cartilage in the wall;
any passage beginning with the primary bronchus
at the fork in the trachea and ending with terti-
ary bronchi, from which air continues into the
bronchioles.
brush border A fringe of microvilli on the apical
surface of an epithelial cell, serving to enhance
surface area and promote absorption. fig. 3.10
buffer 1. A mixture of chemicals that resists
changes in pH when acid or base is added to the

solution. 2. A physiological system that con-
tributes to acid-base balance, specifically the res-
piratory and urinary systems.
bursa A sac filled with synovial fluid at a diarthrosis,
serving to facilitate muscle or joint action. fig. 9.19
C
calcaneal tendon (cal-CAY-nee-ul) A thick tendon
at the heel that attaches the triceps surae mus-
cles to the calcaneus; also called the Achilles ten-
don. fig. 10.37
calcification The hardening of a tissue due to the
deposition of calcium salts.
calcitonin (CAL-sih-TOE-nin) A hormone secreted
by C cells of the thyroid gland that promotes cal-
cium deposition in the skeleton and lowers blood
calcium concentration.
calmodulin An intracellular protein that binds cal-
cium ions and mediates many of the second-mes-
senger effects of calcium.
calorie The amount of thermal energy that will
raise the temperature of 1 g of water by 1°C. Also
called a small calorie.
Calorie See kilocalorie.
calorigenic (ca-LOR-ih-JEN-ic) Heat-producing, as
in the calorigenic effect of thyroid hormone.
calsequestrin A protein found in smooth endoplasmic
reticulum that reversibly binds and stores calcium
ions, rendering calcium chemically unreactive until
needed for such processes as muscle contraction.
calvaria (cal-VERR-ee-uh) The rounded bony dome

that forms the roof of the cranium; the general
portion of the skull superior to the eyes and ears;
skullcap.
calyx (CAY-lix) (plural, calices) A cuplike structure,
as in the kidneys. fig. 23.4
canaliculus (CAN-uh-LIC-you-lus) A microscopic
canal, as in osseous tissue. fig. 7.4
capillary (CAP-ih-LERR-ee) The narrowest type of ves-
sel in the cardiovascular and lymphatic systems;
engages in fluid exchanges with surrounding tissues.
capillary exchange The process of fluid transfer
between the bloodstream and tissue fluid.
capsule The fibrous covering of a structure such as
the spleen or a diarthrosis.
carbohydrate A hydrophilic organic compound
composed of carbon and a 2:1 ratio of hydrogen
to oxygen; includes sugars, starches, glycogen,
and cellulose.
carbonic anhydrase An enzyme found in erythro-
cytes and kidney tubule cells that catalyzes the
decomposition of carbonic acid into carbon diox-
ide and water or the reverse reaction (H
2
CO
3
↔
CO
2
ϩ H
2

O).
carboxyl group (car-BOC-sil) An organic functional
group with the formula –COOH, found in many
organic acids such as amino acids and fatty acids.
carcinogen (car-SIN-oh-jen) An agent capable of
causing cancer, including certain chemicals,
viruses, and ionizing radiation.
cardiac center A nucleus in the medulla oblongata
that regulates autonomic reflexes for controlling
the rate and strength of the heartbeat.
cardiac cycle One complete cycle of cardiac systole
and diastole.
cardiac muscle Striated involuntary muscle of the
heart.
cardiac output (CO) The amount of blood pumped
by each ventricle of the heart in 1 minute.
cardiac reserve The difference between maximum
and resting cardiac output; determines a person’s
tolerance for exercise.
Saladin: Anatomy &
Physiology: The Unity of
Form and Function, Third
Edition
End Matter Glossary
© The McGraw−Hill
Companies, 2003
Glossary G-4
cardiovascular system An organ system consisting
of the heart and blood vessels, serving for the
transport of blood. Compare circulatory system.

carotid body (ca-ROT-id) A small cellular mass
immediately superior to the branch in the com-
mon carotid artery, containing sensory cells that
detect changes in blood pH and carbon dioxide
and oxygen content. fig. 20.11
carotid sinus A dilation of the common carotid
artery at the point where it branches into the
internal and external carotids; contains barore-
ceptors, which monitor changes in blood pressure.
carpal Pertaining to the wrist (carpus).
carrier 1. A protein in a cellular membrane that
performs carrier-mediated transport. 2. A person
who is heterozygous for a recessive allele and
does not exhibit the associated phenotype, but
may transmit this allele to his or her children; for
example, a carrier for sickle-cell disease.
carrier-mediated transport A process of transport-
ing materials through a cellular membrane that
involves reversible binding to a membrane protein.
cartilage A connective tissue with a rubbery matrix,
cells (chondrocytes) contained in lacunae, and no
blood vessels; covers the articular surfaces of many
bones and supports organs such as the ear and larynx.
catabolism (ca-TAB-oh-lizm) Any metabolic reactions
that release energy and break relatively complex
molecules with high free energy into less complex
molecules with lower free energy; for example,
digestion and glycolysis. Compare anabolism.
catalyst (CAT-uh-list) Any chemical that lowers the
activation energy of a chemical reaction and thus

makes the reaction proceed more rapidly; a role
served in cells by enzymes.
catecholamine (CAT-eh-COAL-uh-meen) A subclass
of biogenic amines that includes epinephrine,
norepinephrine, and dopamine. fig. 12.18
cation (CAT-eye-on) An ion with more protons than
electrons and consequently a net positive charge.
caudal (CAW-dul) 1. Pertaining to a tail or narrow
tail-like part of an organ. 2. Pertaining to the
inferior part of the trunk of the body, where the
tail of other animals arises. Compare cranial. 3.
Relatively distant from the forehead, especially in
reference to structures of the brain and spinal
cord; for example, the medulla oblongata is cau-
dal to the pons. Compare rostral.
celiac (SEE-lee-ac) Pertaining to the abdomen.
cell The smallest subdivision of a tissue considered
to be alive; consists of a plasma membrane
enclosing cytoplasm and, in most cases, a nucleus.
cellular membrane Any unit membrane enclosing a
cell or organelle. See also unit membrane.
central Located relatively close to the median axis
of the body, as in the central nervous system;
opposite of peripheral.
central nervous system (CNS) The brain and spinal
cord.
centriole (SEN-tree-ole) An organelle composed of
a short cylinder of nine triplets of microtubules,
usually paired with another centriole perpendicu-
lar to it; origin of the mitotic spindle; identical to

the basal body of a cilium or flagellum. fig. 3.30
cephalic (seh-FAL-ic) Pertaining to the head.
cerebellum (SERR-eh-BEL-um) A large portion of
the brain dorsal to the brainstem and inferior to
the cerebrum, responsible for equilibrium, motor
coordination, and memory of learned motor skills.
fig. 14.9
cerebrospinal fluid (CSF) (SERR-eh-bro-SPY-nul,
seh-REE-bro-SPY-nul) A liquid that fills the ven-
tricles of the brain, the central canal of the spinal
cord, and the space between the CNS and dura
mater.
cerebrovascular accident (CVA) (SERR-eh-bro-
VASS-cue-lur, seh-REE-bro-VASS-cue-lur) The
loss of blood flow to any part of the brain due to
obstruction or hemorrhage of an artery, leading
to the necrosis of nervous tissue; also called
stroke or apoplexy.
cerebrum (SERR-eh-brum, seh-REE-brum) The
largest and most superior part of the brain,
divided into two convoluted cerebral hemispheres
separated by a deep longitudinal fissure.
cervical (SUR-vih-cul) Pertaining to the neck or any
cervix.
cervix (SUR-vix) 1. The neck. 2. A narrow or neck-
like part of an organ such as the uterus and gall-
bladder. fig. 28.3
channel protein A protein in the plasma membrane
that has a pore through it for the passage of
materials between the cytoplasm and extracellu-

lar fluid. fig. 3.6
chemical bond A force that attracts one atom to
another, such as their opposite charges or the
sharing of electrons.
chemical digestion Hydrolysis reactions that occur
in the digestive tract and convert dietary poly-
mers into monomers that can be absorbed by the
small intestine.
chemical synapse A meeting of a nerve fiber and
another cell with which the neuron communi-
cates by releasing neurotransmitters. fig. 12.17
chemoreceptor An organ or cell specialized to
detect chemicals, as in the carotid bodies and
taste buds.
chemotaxis (KEM-oh-TAC-sis) The movement of a
cell along a chemical concentration gradient,
especially the attraction of neutrophils to chemi-
cals released by pathogens or inflamed tissues.
chief cells The majority type of cell in an organ or
tissue such as the parathyroid glands or gastric
glands.
choanae (co-AH-nee) Openings of the nasal cavity into
the pharynx; also called posterior nares. fig. 22.3
cholecystokinin (CCK) (CO-leh-SIS-toe-KY-nin) A
polypeptide employed as a hormone and neuro-
transmitter, secreted by some brain neurons and
cells of the digestive tract. fig. 12.18
cholesterol (co-LESS-tur-ol) A steroid that func-
tions as part of the plasma membrane and as a
precursor for all other steroids in the body.

cholinergic (CO-lin-UR-jic) Pertaining to acetyl-
choline (ACh), as in cholinergic nerve fibers that
secrete ACh, cholinergic receptors that bind it, or
cholinergic effects on a target organ.
chondrocyte (CON-dro-site) A cartilage cell; a for-
mer chondroblast that has become enclosed in a
lacuna in the cartilage matrix. fig. 7.9
chorion (CO-ree-on) A fetal membrane external to
the amnion; forms part of the placenta and has
diverse functions including fetal nutrition, waste
removal, and hormone secretion. fig. 29.9
chromatid (CRO-muh-tid) One of two genetically
identical rodlike bodies of a metaphase chromo-
some, joined to its sister chromatid at the cen-
tromere. fig. 4.14
chromatin (CRO-muh-tin) Filamentous material in
the interphase nucleus, composed of DNA and
associated proteins.
chromosome A complex of DNA and protein carry-
ing the genetic material of a cell’s nucleus. Nor-
mally there are 46 chromosomes in the nucleus of
each cell except germ cells. fig. 4.14
chronic 1. Long-lasting. 2. Pertaining to a disease
that progresses slowly and has a long duration.
Compare acute.
chronic bronchitis A chronic obstructive pulmonary
disease characterized by damaged and immobilized
respiratory cilia, excessive mucus secretion, infec-
tion of the lower respiratory tract, and bronchial
inflammation; caused especially by cigarette smok-

ing. See also chronic obstructive pulmonary disease.
chronic obstructive pulmonary disease (COPD) A
group of lung diseases (asthma, chronic bronchi-
tis, and emphysema) that result in long-term
obstruction of airflow and substantially reduced
pulmonary ventilation; one of the leading causes
of death in old age.
chylomicron (KY-lo-MY-cron) A protein-coated lipid
droplet formed in the small intestine and found in
the lymph and blood after a meal; a means of lipid
transport in the bloodstream and lymph.
chyme (kime) A slurry of partially digested food in
the stomach and small intestine.
cilium (SIL-ee-um) A hairlike process, with an axoneme,
projecting from the apical surface of an epithelial
cell; often motile and serving to propel matter across
the surface of an epithelium, but sometimes non-
motile and serving sensory roles. fig. 3.12
circulatory shock A state of cardiac output inade-
quate to meet the metabolic needs of the body.
circulatory system An organ system consisting of
the heart, blood vessels, and blood. Compare car-
diovascular system.
circumduction A joint movement in which one end
of an appendage remains relatively stationary and
the other end is moved in a circle. fig. 9.12
cirrhosis (sih-RO-sis) A degenerative liver disease
characterized by replacement of functional
parenchyma with fibrous and adipose tissue;
causes include alcohol, other poisons, and viral and

bacterial inflammation.
cisterna (sis-TUR-nuh) A fluid-filled space or sac, such
as the cisterna chyli of the lymphatic system and a
cisterna of the endoplasmic reticulum or Golgi com-
plex. fig. 3.26
citric acid cycle A cyclic reaction series involving
several carboxylic acids in the mitochondrial
matrix; oxidizes acetyl groups to carbon dioxide
while reducing NAD
ϩ
to NADH and FADH to
FADH
2
, making these reduced coenzymes avail-
able for ATP synthesis. Also called the Krebs cycle
or tricarboxylic acid (TCA) cycle. fig. 26.4
climacteric A period in the lives of men and
women, usually in the early 50s, marked by
changes in the level of reproductive hormones, a
variety of somatic and psychological effects, and
in women, cessation of ovulation and menstrua-
tion (menopause).
Saladin: Anatomy &
Physiology: The Unity of
Form and Function, Third
Edition
End Matter Glossary
© The McGraw−Hill
Companies, 2003
clone A population of cells that are mitotically

descended from the same parent cell and are iden-
tical to each other genetically or in other respects.
coagulation (co-AG-you-LAY-shun) The clotting of
blood, lymph, tissue fluid, or semen.
codominant (co-DOM-ih-nent) A condition in
which neither of two alleles is dominant over the
other, and both are phenotypically expressed
when both are present in an individual; for exam-
ple, blood type alleles I
A
and I
B
produce blood
type AB when inherited together.
codon A series of three nucleotides in mRNA that
codes for one amino acid in a protein or, as a stop
codon, signals the end of a gene.
coenzyme (co-EN-zime) A small organic molecule,
usually derived from a vitamin, that is needed to
make an enzyme catalytically active; acts by
accepting electrons from an enzymatic reaction and
transferring them to a different reaction chain.
cofactor A nonprotein such as a metal ion or coen-
zyme needed for an enzyme to function.
cohesion The clinging of identical molecules such
as water to each other.
collagen (COLL-uh-jen) The most abundant protein
in the body, forming the fibers of many connec-
tive tissues in places such as the dermis, tendons,
and bones.

colloid An aqueous mixture of particles that are too
large to pass through most selectively permeable
membranes but small enough to remain evenly
dispersed through the solvent by the thermal
motion of solvent particles; for example, the pro-
teins in blood plasma.
colloid osmotic pressure (COP) A portion of the
osmotic pressure of a body fluid that is due to its
protein. Compare oncotic pressure.
colostrum (co-LOS-trum) A watery, low-fat secre-
tion of the mammary gland that nourishes and
immunizes an infant for the first 2 to 3 days
postpartum, until true milk is secreted.
commissure (COM-ih-shur) 1. A bundle of nerve
fibers that crosses from one side of the brain or
spinal cord to the other. 2. A corner or angle at
which the eyelids, lips, or genital labia meet; in
the eye, also called the canthus. fig. 16.20
complement 1. To complete or enhance the struc-
ture or function of something else, as in the coor-
dinated action of two different hormones. 2. A sys-
tem of plasma proteins involved in nonspecific
defense against pathogens.
computerized tomography (CT) A method of med-
ical imaging that uses X rays and a computer to
create an image of a thin section of the body;
also called a CT scan.
concentration gradient A difference in chemical
concentration from one point to another, as on
two sides of a plasma membrane.

conception The fertilization of an egg, producing a
zygote.
conceptus All products of conception, ranging from
a fertilized egg to the full-term fetus with its
embryonic membranes, placenta, and umbilical
cord. Compare embryo, fetus.
condyle (CON-dile) A rounded knob on a bone serv-
ing to produce smooth motion at a joint. fig. 8.2
conformation The three-dimensional structure of a
protein that results from interaction among its
amino acid side groups, its interactions with
water, and the formation of disulfide bonds.
congenital Present at birth; for example, an
anatomical defect, a syphilis infection, or a
hereditary disease.
conjugated A state in which one organic compound
is bound to another compound of a different class,
such as a protein conjugated with a carbohydrate
to form a glycoprotein.
connective tissue A tissue usually composed of
more extracellular than cellular volume and usu-
ally with a substantial amount of extracellular
fiber; forms supportive frameworks and capsules
for organs, binds structures together, holds them
in place, stores energy (as in adipose tissue), or
transports materials (as in blood).
contractility 1. The ability to shorten. 2. The
amount of force that a contracting muscle fiber
generates for a given stimulus; may be increased
by epinephrine, for example, while stimulus

strength remains constant.
contralateral On opposite sides of the body, as in
reflex arcs where the stimulus comes from one
side of the body and a response is given by mus-
cles on the other side. Compare ipsilateral.
convergent Coming together, as in a convergent
muscle and a converging neuronal circuit.
cooperative effects Effects in which two hormones,
or both divisions of the autonomic nervous system,
work together to produce a single overall result.
cornified Having a heavy deposit of keratin, as in
the stratum corneum of the epidermis.
corona A halo- or crownlike structure, as in the
corona radiata or the coronal suture of the skull.
coronal plane See frontal plane.
corona radiata 1. An array of nerve tracts in the
brain that arise mainly from the thalamus and fan
out to different regions of the cerebral cortex. 2.
The first layer of cuboidal cells immediately exter-
nal to the zona pellucida around an egg cell.
coronary circulation A system of blood vessels that
serve the wall of the heart. fig. 19.10
corpus Body or mass; the main part of an organ, as
opposed to such regions as a head, tail, or cervix.
corpus callosum (COR-pus ca-LO-sum) A prominent
C-shaped band of nerve tracts that connect the
right and left cerebral hemispheres to each other,
seen superior to the third ventricle in a median
section of the brain. fig. 14.1
corpus luteum (LOO-tee-um) A yellowish cellular

mass that forms in the ovary from a follicle that
has ovulated; secretes progesterone, hormonally
regulates the second half of the menstrual cycle,
and is essential to sustaining the first 7 weeks of
pregnancy.
cortex (plural, cortices) The outer layer of some
organs such as the adrenal gland, cerebrum,
lymph node, and ovary; usually covers or encloses
tissue called the medulla.
corticosteroid (COR-tih-co-STERR-oyd) Any steroid
hormone secreted by the adrenal cortex, such as
aldosterone, cortisol, and sex steroids.
costal (COSS-tul) Pertaining to the ribs.
costal cartilage A bladelike plate of hyaline cartilage
that attaches the distal end of a rib to the sternum.
cotransport A form of carrier-mediated transport in
which a membrane protein transports two solutes
simultaneously or within the same cycle of
action; for example the sodium-glucose transport
protein and the Na
ϩ
-K
ϩ
pump.
countercurrent A situation in which two fluids flow
side by side in opposite directions, as in the coun-
tercurrent multiplier of the kidney and the coun-
tercurrent heat exchanger of the scrotum.
cranial (CRAY-nee-ul) 1. Pertaining to the cranium.
2. In a position relatively close to the head or a

direction toward the head. Compare caudal.
cranial nerve Any of 12 pairs of nerves connected
to the base of the brain and passing through
foramina of the cranium.
creatine phosphate (CP) (CREE-uh-teen FOSS-fate)
An energy-storage molecule in muscle tissue that
donates a phosphate group to ADP and thus
regenerates ATP in periods of hypoxia.
crista A crestlike structure, such as the crista galli of
the ethmoid bone or the crista of a mitochondrion.
cross section A cut perpendicular to the long axis
of the body or an organ.
crural (CROO-rul) Pertaining to the leg proper or to
the crus of a organ. See crus.
crus (cruss) (plural, crura) 1. The leg proper; the
region from the knee to the ankle. 2. A leglike
extension of an organ such as the penis and cli-
toris. figs. 27.7, 28.8
cuboidal (cue-BOY-dul) A cellular shape that is
roughly like a cube or in which the height and
width are about equal.
cuneiform (cue-NEE-ih-form) Wedge-shaped, as in
the cuneiform cartilages of the larynx and
cuneiform bone of the wrist.
current A moving stream of charged particles such
as ions or electrons.
cusp 1. One of the flaps of a valve of the heart,
veins, and lymphatic vessels. 2. A conical projec-
tion on the occlusal surface of a premolar or
molar tooth.

cutaneous (cue-TAY-nee-us) Pertaining to the skin.
cyanosis (SY-uh-NO-sis) A bluish color of the skin
and mucous membranes due to ischemia or
hypoxemia.
cyclic adenosine monophosphate (cAMP) A cyclic
molecule produced from ATP by the action of
adenylate cyclase; serves as a second messenger
in many hormone and neurotransmitter actions.
fig. 2.29b
cyclooxygenase An enzyme that converts arachi-
donic acid to prostacyclin, prostaglandins, and
thromboxanes.
cytochromes Enzymes on the mitochondrial cristae
that transfer electrons in the final reaction chain
of aerobic respiration.
cytokinesis (SY-toe-kih-NEE-sis) Division of the
cytoplasm of a cell into two cells following
nuclear division.
cytology The study of cell structure and function.
cytolysis (sy-TOL-ih-sis) The rupture and destruction
of a cell by such agents as complement proteins and
hypotonic solutions.
cytoplasm The contents of a cell between its
plasma membrane and its nuclear envelope, con-
sisting of cytosol, organelles, inclusions, and the
cytoskeleton.
cytosine A single-ringed nitrogenous base (pyrimi-
dine) found in DNA; one of the four bases of the
G-5 Glossary
Saladin: Anatomy &

Physiology: The Unity of
Form and Function, Third
Edition
End Matter Glossary
© The McGraw−Hill
Companies, 2003
Glossary G-6
genetic code; complementary to guanine in the
double helix of DNA. fig. 4.2
cytoskeleton A system of protein microfilaments,
intermediate filaments, and microtubules in a cell,
serving in physical support, cellular movement,
and the routing of molecules and organelles to
their destinations within the cell. fig. 3.31
cytosol A clear, featureless, gelatinous colloid in
which the organelles and other internal structures
of a cell are embedded.
cytotoxic T cell A T lymphocyte that directly
attacks and destroys infected body cells, cancer-
ous cells, and the cells of transplanted tissues.
D
daughter cells Cells that arise from a parent cell by
mitosis or meiosis.
deamination (dee-AM-ih-NAY-shun) Removal of an
amino group from an organic molecule; a step in
the catabolism of amino acids.
decomposition reaction A chemical reaction in
which a larger molecule is broken down into
smaller ones. Compare synthesis reaction.
decussation (DEE-cuh-SAY-shun) The crossing of

nerve fibers from the right side of the central
nervous system to the left or vice versa, especially
in the spinal cord, medulla oblongata, and optic
chiasm.
deep Relatively far from the body surface; opposite
of superficial. For example, the bones are deep to
the skeletal muscles.
degranulation Exocytosis and disappearance of
cytoplasmic granules, especially in platelets and
granulocytes.
dehydration synthesis A reaction in which two
chemical monomers are joined together with water
produced as a by-product; also called a condensa-
tion reaction. Compare hydrolysis.
denaturation A change in the three-dimensional
conformation of a protein that destroys its enzy-
matic or other functional properties, usually
caused by extremes of temperature or pH.
dendrites Processes of a neuron that receive infor-
mation from other cells or from environmental
stimuli and conduct signals to the soma. Den-
drites are usually shorter, more branched, and
more numerous than the axon and are incapable
of producing action potentials. fig. 12.4
dendritic cell An antigen-presenting cell of the epi-
dermis and mucous membranes. fig. 6.2
denervation atrophy The shrinkage of skeletal mus-
cle that occurs when its motor neuron dies or is
severed from the muscle.
dense connective tissue A connective tissue with a

high density of fiber, relatively little ground sub-
stance, and scanty cells; seen in tendons and the
dermis, for example.
deoxyribonucleic acid (DNA) (dee-OCK-see-RY-bo-
new-CLAY-ic) A very large nucleotide polymer that
carries the genes of a cell; composed of a double
helix of intertwined chains of deoxyribose and phos-
phate, with complementary pairs of nitrogenous
bases facing each other between the helices. fig. 4.3
depolarization A shift in the electrical potential
across a plasma membrane toward 0 mV, associ-
ated with excitation of a nerve or muscle cell.
Compare hyperpolarization.
dermal papillae Bumps or ridges of dermis that
extend upward to interdigitate with the epidermis
and create a wavy boundary that resists stress and
slippage of the epidermis.
dermis The deeper of the two layers of the skin,
underlying the epidermis and composed of
fibrous connective tissue.
desmosome (DEZ-mo-some) A patchlike intercellu-
lar junction that mechanically links two cells
together. fig. 5.29
dextrose An isomer of glucose; the only form of
glucose with a normal role in physiology.
diabetes (DY-uh-BEE-teez) Any disease character-
ized by chronic polyuria of metabolic origin; dia-
betes mellitus unless otherwise specified.
diabetes insipidus (in-SIP-ih-dus) A form of dia-
betes that results from hyposecretion of antidi-

uretic hormone; unlike other forms, it is not char-
acterized by hyperglycemia or glycosuria.
diabetes mellitus (DM) (mel-EYE-tus) A form of
diabetes that results from hyposecretion of
insulin or from a deficient target cell response to
it; signs include hyperglycemia and glycosuria.
dialysis (dy-AL-ih-sis) 1. The separation of some
solute particles from others by diffusion through
a selectively permeable membrane. 2. Hemodialy-
sis, the process of separating wastes from the
bloodstream and sometimes adding other sub-
stances to it (such as drugs and nutrients) by cir-
culating the blood through a machine with a
selectively permeable membrane, used to treat
cases of renal or hepatic insufficiency.
diapedesis (DY-uh-peh-DEE-sis) Migration of
formed elements of the blood through a capillary
or venule wall into the interstitial space. fig. 21.16
diaphysis (dy-AFF-ih-sis) The shaft of a long bone.
fig. 7.2
diarthrosis (DY-ar-THRO-sis) A freely movable syn-
ovial joint such as the knuckle, elbow, shoulder, or
knee.
diastole (dy-ASS-tuh-lee) A period in which a heart
chamber relaxes and fills with blood; especially
ventricular relaxation.
diencephalon (DY-en-SEFF-uh-lon) A portion of the
brain between the midbrain and corpus callosum;
composed of the thalamus, epithalamus, and
hypothalamus. fig. 14.12

differentiation Development of a relatively unspe-
cialized cell or tissue into one with a more spe-
cific structure and function.
diffusion Spontaneous net movement of particles
from a place of high concentration to a place of
low concentration.
dilation (dy-LAY-shun) Widening of an organ or
passageway such as a blood vessel or the pupil of
the eye.
diploid (2n) Pertaining to a cell or organism with
chromosomes in homologous pairs.
disaccharide (dy-SAC-uh-ride) A carbohydrate
composed of two simple sugars (monosaccha-
rides) joined by a glycosidic bond; for example,
lactose, sucrose, and maltose. fig. 2.17
disseminated intravascular coagulation (DIC)
Widespread clotting of the blood within unbroken
vessels, leading to hemorrhaging, congestion of
the vessels with clotted blood, and ischemia and
necrosis of organs.
distal Relatively distant from a point of origin or
attachment; for example, the wrist is distal to the
elbow. Compare proximal.
disulfide bond A covalent bond between the sulfur
atoms of two cysteine residues, serving to link one
polypeptide chain to another or to hold a single
chain in its three-dimensional conformation.
diuretic (DY-you-RET-ic) A chemical that increases
urine output.
dizygotic (DZ) twins Two individuals who devel-

oped simultaneously in one uterus but originated
from separate fertilized eggs and therefore are
not genetically identical.
dominant 1. Pertaining to a genetic allele that is
phenotypically expressed in the presence of any
other allele. 2. Pertaining to a trait that results
from a dominant allele.
dopamine (DOE-puh-meen) An inhibitory cate-
cholamine neurotransmitter of the central nervous
system, especially of the basal nuclei, where it acts
to suppress unwanted motor activity. fig 12.18
dorsal Toward the back (spinal) side of the body.
dorsal root A branch of a spinal nerve that enters
the spinal cord on its dorsal side, composed of
sensory fibers. fig. 13.8
dorsiflexion (DOR-sih-FLEC-shun) A movement of
the ankle that reduces the joint angle and raises
the toes. fig. 9.14
Down syndrome See trisomy-21.
duodenum (DEW-oh-DEE-num, dew-ODD-eh-num)
The first portion of the small intestine extending
for about 25 cm from the pyloric valve of the
stomach to a sharp bend called the duodenojeju-
nal flexure; receives chyme from the stomach and
secretions from the liver and pancreas. fig. 25.23
dynamic equilibrium 1. A state of continual
change that is controlled within narrow limits, as
in homeostasis and chemical equilibrium. 2. The
sense of motion or acceleration of the body.
dynein (DINE-een) A motor protein involved in the

beating of cilia and flagella and in the movement
of molecules and organelles within cells, as in ret-
rograde transport in a nerve fiber.
E
ectoderm The outermost of the three primary germ
layers of an embryo; gives rise to the nervous sys-
tem and epidermis.
ectopic (ec-TOP-ic) In an abnormal location; for
example, ectopic pregnancy and ectopic pace-
makers of the heart.
edema (eh-DEE-muh) Abnormal accumulation of
tissue fluid resulting in swelling of the tissue.
effector A molecule, cell, or organ that carries out a
response to a stimulus.
efferent (EFF-ur-unt) Carrying away or out, such as a
blood vessel that carries blood away from a tissue
or a nerve fiber that conducts signals away from
the central nervous system. Compare afferent.
eicosanoids (eye-CO-sah-noyds) Twenty-carbon
derivatives of arachidonic acid that function as
intercellular messengers; includes prostaglandins,
prostacyclin, leukotrienes, and thromboxanes.
Saladin: Anatomy &
Physiology: The Unity of
Form and Function, Third
Edition
End Matter Glossary
© The McGraw−Hill
Companies, 2003
elastic fiber A connective tissue fiber, composed of

the protein elastin, that stretches under tension
and returns to its original length when released;
responsible for the resilience of organs such as
the skin and lungs.
elasticity The tendency of a stretched structure to
return to its original dimensions when tension is
released.
electrical synapse A gap junction that enables one
cell to stimulate another directly, without the
intermediary action of a neurotransmitter; such
synapses connect the cells of cardiac muscle and
single-unit smooth muscle.
electrochemical gradient A difference in ion concen-
tration from one point to another (especially across
a plasma membrane) resulting in a gradient of both
chemical concentration and electrical charge.
electrolyte A salt that ionizes in water and pro-
duces a solution that conducts electricity; loosely
speaking, any ion that results from the dissocia-
tion of such salts, such as sodium, potassium, cal-
cium, chloride, and bicarbonate ions.
elevation A joint movement that raises a body part,
as in hunching the shoulders or closing the mouth.
embolism (EM-bo-lizm) The obstruction of a blood
vessel by an embolus.
embolus (EM-bo-lus) Any abnormal traveling object
in the bloodstream, such as agglutinated bacteria
or blood cells, a blood clot, or an air bubble.
embryo A developing individual from the end of
the second week of gestation when the three pri-

mary germ layers have formed, through the end
of the eighth week when all of the organ systems
are present. Compare conceptus, fetus.
emphysema (EM-fih-SEE-muh) A degenerative lung
disease characterized by a breakdown of alveoli
and diminishing surface area available for gas
exchange; occurs with aging of the lungs but is
greatly accelerated by smoking or air pollution.
emulsion A suspension of one liquid in another,
such as oil in water or fat in the lymph.
endocrine gland (EN-doe-crin) A ductless gland
that secretes hormones into the bloodstream; for
example, the thyroid and adrenal glands. Com-
pare exocrine gland.
endocytosis (EN-doe-sy-TOE-sis) Any process in
which a cell forms vesicles from its plasma mem-
brane and takes in large particles, molecules, or
droplets of extracellular fluid; for example,
phagocytosis and pinocytosis.
endoderm The innermost of the three primary germ
layers of an embryo; gives rise to the mucosae of
the digestive and respiratory tracts and to their
associated glands.
endogenous (en-DODJ-eh-nus) Originating inter-
nally, such as the endogenous cholesterol synthe-
sized in the body in contrast to the exogenous
cholesterol coming from the diet. Compare
exogenous.
endometrium (EN-doe-MEE-tree-um) The mucosa
of the uterus; the site of implantation and source

of menstrual discharge.
endoplasmic reticulum (ER) (EN-doe-PLAZ-mic
reh-TIC-you-lum) An extensive system of inter-
connected cytoplasmic tubules or channels; clas-
sified as rough ER or smooth ER depending on the
presence or absence of ribosomes on its mem-
brane. fig. 3.26
endothelium (EN-doe-THEEL-ee-um) A simple
squamous epithelium that lines the lumens of the
blood vessels, heart, and lymphatic vessels.
endurance exercise A form of physical exercise, such
as running or swimming, that promotes cardiopul-
monary efficiency and fatigue resistance more than
muscular strength. Compare resistance exercise.
enteric (en-TERR-ic) Pertaining to the small intes-
tine, as in enteric hormones.
enzyme A protein that functions as a catalyst.
enzyme amplification A series of chemical reactions
in which the product of one step is an enzyme
that produces an even greater number of product
molecules at the next step, resulting in a rapidly
increasing amount of reaction product. Seen in
hormone action and blood clotting, for example.
eosinophil (EE-oh-SIN-oh-fill) A granulocyte with a
large, often bilobed nucleus and coarse cytoplas-
mic granules that stain with eosin; phagocytizes
antigen-antibody complexes, allergens, and
inflammatory chemicals and secretes enzymes
that combat parasitic infections. table 18.8
epidermis A stratified squamous epithelium that

constitutes the superficial layer of the skin over-
lying the dermis. fig. 6.2
epinephrine (EP-ih-NEFF-rin) A catecholamine that
functions as a neurotransmitter in the sympathetic
nervous system and as a hormone secreted by the
adrenal medulla; also called adrenaline. fig. 12.18
epiphyseal plate (EP-ih-FIZZ-ee-ul) A plate of hya-
line cartilage between the epiphysis and diaphysis
of a long bone in a child or adolescent, serving as
a growth zone for bone elongation. fig. 7.11
epiphysis (eh-PIF-ih-sis) 1. The head of a long
bone. 2. The pineal gland (epiphysis cerebri).
epithelium A type of tissue consisting of one or more
layers of closely adhering cells with little intercellu-
lar material and no blood vessels; forms the cover-
ings and linings of many organs and the
parenchyma of the glands.
erectile tissue A tissue that functions by swelling
with blood, as in the penis and clitoris and infe-
rior concha of the nasal cavity.
erythema (ERR-ih-THEE-muh) Abnormal redness of
the skin due to such causes as burns, inflamma-
tion, and vasodilation.
erythrocyte (eh-RITH-ro-site) A red blood cell.
erythropoiesis (eh-RITH-ro-poy-EE-sis) The produc-
tion of erythrocytes.
erythropoietin (eh-RITH-ro-POY-eh-tin) A hormone
that is secreted by the kidneys and liver in response
to hypoxemia and stimulates erythropoiesis.
estrogens (ESS-tro-jenz) A family of steroid hor-

mones known especially for producing female sec-
ondary sex characteristics and regulating various
aspects of the menstrual cycle and pregnancy;
major forms are estradiol, estriol, and estrone.
evolution A change in the relative frequencies of
alleles in a population over a period of time; the
mechanism that produces adaptations in human
form and function. See also adaptation.
excitability The ability of a cell to respond to a
stimulus, especially the ability of nerve and mus-
cle cells to produce membrane voltage changes in
response to stimuli; irritability.
excitation-contraction coupling Events that link
the synaptic stimulation of a muscle cell to the
onset of contraction.
excitatory postsynaptic potential (EPSP) A partial
depolarization of a postsynaptic neuron or muscle
cell in response to a neurotransmitter, making it
more likely to reach threshold and produce an
action potential.
excretion The process of eliminating metabolic
waste products from a cell or from the body.
Compare secretion.
exocrine gland (EC-so-crin) A gland that secretes its
products into another organ or onto the body sur-
face, usually by way of a duct; for example, sali-
vary and gastric glands. Compare endocrine gland.
exocytosis (EC-so-sy-TOE-sis) A process in which a
vesicle in the cytoplasm of a cell fuses with the
plasma membrane and releases its contents from

the cell; used in the elimination of cellular wastes
and in the release of gland products and neuro-
transmitters.
exogenous (ec-SODJ-eh-nus) Originating exter-
nally, such as exogenous (dietary) cholesterol;
extrinsic. Compare endogenous.
expiration 1. Exhaling. 2. Dying.
extension Movement of a joint that increases the
angle between articulating bones (straightens
the joint). Compare flexion. fig. 9.9
extracellular fluid (ECF) Any body fluid that is not
contained in the cells; for example, blood, lymph,
and tissue fluid.
extrinsic (ec-STRIN-sic) 1. Originating externally,
such as extrinsic blood-clotting factors; exogenous.
2. Not fully contained within an organ but acting
on it, such as the extrinsic muscles of the hand and
eye. Compare intrinsic.
exude (ec-SUDE) To seep out, such as fluid filtering
from blood capillaries.
F
facilitated diffusion The process of transporting a
chemical through a cellular membrane, down its
concentration gradient, with the aid of a carrier
that does not consume ATP; enables substances to
diffuse through the membrane that would do so
poorly, or not at all, without a carrier.
facilitation Making a process more likely to occur,
such as the firing of a neuron, or making it occur
more easily or rapidly, as in facilitated diffusion.

fallopian tube See uterine tube.
fascia (FASH-ee-uh) A layer of connective tissue
between the muscles (deep fascia) or separating the
muscles from the skin (superficial fascia). fig. 10.1
fascicle (FASS-ih-cul) A bundle of muscle or nerve
fibers ensheathed in connective tissue; multiple
fascicles bound together constitute a muscle or
nerve as a whole. fig. 10.1
fat 1. A triglyceride molecule. 2. Adipose tissue.
fatty acid An organic molecule composed of a
chain of an even number of carbon atoms with a
carboxyl group at one end and a methyl group at
the other; one of the structural subunits of
triglycerides and phospholipids.
fenestrated (FEN-eh-stray-ted) Perforated with
holes or slits, as in fenestrated blood capillaries
and the elastic sheets of large arteries. fig. 20.6
fetus In human development, an individual from
the beginning of the ninth week when all of the
G-7 Glossary
Saladin: Anatomy &
Physiology: The Unity of
Form and Function, Third
Edition
End Matter Glossary
© The McGraw−Hill
Companies, 2003
Glossary G-8
organ systems are present, through the time of
birth. Compare conceptus, embryo.

fibrin (FY-brin) A sticky fibrous protein formed from
fibrinogen in blood, tissue fluid, lymph, and semen;
forms the matrix of a blood clot.
fibroblast A connective tissue cell that produces
collagen fibers and ground substance; the only
type of cell in tendons and ligaments.
fibrosis Replacement of damaged tissue with
fibrous scar tissue rather than by the original tis-
sue type; scarring. Compare regeneration.
fibrous connective tissue Any connective tissue
with a preponderance of fiber, such as areolar,
reticular, dense regular, and dense irregular con-
nective tissues.
filtrate A fluid formed by filtration, as at the renal
glomerulus and other capillaries.
filtration A process in which hydrostatic pressure
forces a fluid through a selectively permeable
membrane (especially a capillary wall).
fire To produce an action potential, as in nerve and
muscle cells.
fix 1. To hold a structure in place, for example, by fix-
ator muscles that prevent unwanted joint move-
ments. 2. To preserve a tissue by means of a fixative.
fixative A chemical that preserves tissues from
decay, such as formalin.
flagellum (fla-JEL-um) A long, motile, usually single
hairlike extension of a cell; the tail of a sperm cell is
the only functional flagellum in humans. fig. 27.18
flexion A joint movement that, in most cases,
decreases the angle between two bones. Compare

extension. fig. 9.9
fluid balance See water balance.
fluid compartments Any of the major categories of
fluid in the body, separated by selectively perme-
able membranes and differing from each other in
chemical composition. Primary examples are the
intracellular fluid, tissue fluid, blood, and lymph.
fluid-mosaic model The current theory of the
structure of a plasma membrane, depicting it as a
bilayer of phospholipids and cholesterol with
embedded proteins, many of which are able to
move about in the lipid film. fig. 3.6
follicle (FOLL-ih-cul) 1. A small space, such as a hair
follicle, thyroid follicle, or ovarian follicle. 2. An
aggregation of lymphocytes in a lymphatic organ
or mucous membrane.
follicle-stimulating hormone (FSH) A hormone
secreted by the anterior pituitary gland that stim-
ulates development of the ovarian follicles and
egg cells.
foramen (fo-RAY-men) A hole through a bone or
other organ, in many cases providing passage for
blood vessels and nerves.
formed element An erythrocyte, leukocyte, or
platelet; any cellular component of blood or
lymph as opposed to the extracellular fluid com-
ponent.
fossa (FOSS-uh) A depression in an organ or tissue,
such as the fossa ovalis of the heart or a cranial
fossa of the skull.

fovea (FOE-vee-uh) A small pit, such as the fovea
capitis of the femur or fovea centralis of the retina.
free energy The potential energy in a chemical that
is available to do work.
free radical A particle derived from an atom or
molecule, having an unpaired electron that makes
it highly reactive and destructive to cells; pro-
duced by intrinsic processes such as aerobic respi-
ration and by extrinsic agents such as chemicals
and ionizing radiation.
frontal plane An anatomical plane that passes
through the body or an organ from right to left
and superior to inferior; also called a coronal
plane. fig. A.3
functional group A group of atoms, such as a car-
boxyl or amino group, that determines the func-
tional characteristics of an organic molecule.
fundus The base, the broadest part, or the part far-
thest from the opening of certain viscera such as
the stomach and uterus.
fusiform (FEW-zih-form) Spindle-shaped; elon-
gated, thick in the middle, and tapered at both
ends, such as the shape of a smooth muscle cell
or a muscle spindle.
G
gamete (GAM-eet) An egg or sperm cell.
gametogenesis (GAM-eh-toe-JEN-eh-sis) The pro-
duction of eggs or sperm.
gamma-(␥-)aminobutyric acid (GABA) (ah-MEE-
no-byu-TIRR-ic) An inhibitory neurotransmitter of

the central nervous system in the biogenic amine
class. fig. 12.18
gamma (␥) globulins (GLOB-you-lins) A class of
relatively large proteins found in the blood
plasma and on the surfaces of immune cells,
functioning as antibodies. See also globulin.
ganglion (GANG-glee-un) A cluster of nerve cell
bodies in the peripheral nervous system, often
resembling a knot in a string.
gangrene Tissue necrosis resulting from ischemia.
gap junction A junction between two cells consisting
of a pore surrounded by a ring of proteins in the
plasma membrane of each cell, allowing solutes to
diffuse from the cytoplasm of one cell to the next;
functions include cell-to-cell nutrient transfer in
the developing embryo and electrical communica-
tion between cells of cardiac and smooth muscle.
See also electrical synapse. fig. 5.29
gastric Pertaining to the stomach.
gate A protein channel in a cellular membrane that
can open or close in response to chemical, electrical,
or mechanical stimuli, thus controlling when sub-
stances are allowed to pass through the membrane.
gene A segment of DNA that codes for the synthe-
sis of one protein.
gene locus The site on a chromosome where a
given gene is located.
generator potential A graded, reversible rise in the
local voltage across the plasma membrane of a
nerve or muscle cell in response to a stimulus;

triggers an action potential if it reaches threshold.
genetic engineering Any of several techniques that
alter the genetic constitution of a cell or organ-
ism, including recombinant DNA technology and
gene substitution therapy.
genome (JEE-nome) All the genes of one individual,
estimated at 35,000 genes in humans.
genotype (JEE-no-type) The pair of alleles pos-
sessed by an individual at one gene locus on a
pair of homologous chromosomes; strongly influ-
ences the individual’s phenotype for a given trait.
germ cell A gamete or any precursor cell destined
to become a gamete.
germ layer Any of first three tissue layers of an
embryo: ectoderm, mesoderm, or endoderm.
gestation (jess-TAY-shun) Pregnancy.
gland Any organ specialized to produce a secretion;
in some cases a single cell, such as a goblet cell.
glaucoma (glaw-CO-muh) A visual disease in which
an excessive amount of aqueous humor accumu-
lates and creates pressure that is transmitted
through the lens and vitreous body to the retina;
pressure on the blood vessels of the choroid
causes ischemia, retinal necrosis, and blindness.
globulin (GLOB-you-lin) A globular protein such as
an enzyme, antibody, or albumin; especially a
family of proteins in the blood plasma that
includes albumin, antibodies, fibrinogen, and pro-
thrombin.
glomerular capsule (glo-MERR-you-lur) A double-

walled capsule around each glomerulus of the
kidney; receives glomerular filtrate and empties
into the proximal convoluted tubule. Also called
Bowman’s capsule. fig. 23.6
glomerulus A spheroid mass of blood capillaries in
the kidney that filters plasma and produces
glomerular filtrate, which is further processed to
form the urine. fig. 23.6
glucagon (GLUE-ca-gon) A hormone secreted by ␣
cells of the pancreatic islets in response to hypo-
glycemia; promotes glycogenolysis and other
effects that raise blood glucose concentration.
glucocorticoid (GLUE-co-COR-tih-coyd) Any hor-
mone of the adrenal cortex that affects carbohy-
drate, fat, and protein metabolism; chiefly corti-
sol and corticosterone.
gluconeogenesis (GLUE-co-NEE-oh-JEN-eh-sis) The
synthesis of glucose from noncarbohydrates such
as fats and amino acids.
glucose A monosaccharide (C
6
H
12
O
6
) also known as
blood sugar; glycogen, starch, cellulose, and malt-
ose are made entirely of glucose, and glucose
constitutes half of a sucrose or lactose molecule.
The isomer involved in human physiology is also

called dextrose.
glucose-sparing effect An effect of fats or other
energy substrates in which they are used as fuel
by most cells, so that those cells do not consume
glucose; this makes more glucose available to
cells such as neurons that cannot use alternative
energy substrates.
glycerol (GLISS-er-ol) A viscous three-carbon alco-
hol that forms the structural backbone of triglyc-
eride and phospholipid molecules; also called
glycerin.
glycocalyx (GLY-co-CAY-licks) A layer of carbohy-
drate molecules covalently bonded to the phos-
pholipid and protein molecules of a plasma mem-
brane; forms a surface coat on all human cells.
glycogen (GLY-co-jen) A glucose polymer synthe-
sized by liver, muscle, uterine, and vaginal cells
that serves as an energy-storage polysaccharide.
glycogenesis (GLY-co-JEN-eh-sis) The synthesis of
glycogen.
glycogenolysis (GLY-co-jeh-NOLL-ih-sis) The
hydrolysis of glycogen, releasing glucose.
glycolipid (GLY-co-LIP-id) A phospholipid molecule
with a carbohydrate covalently bonded to it,
found in the plasma membranes of cells.
Saladin: Anatomy &
Physiology: The Unity of
Form and Function, Third
Edition
End Matter Glossary

© The McGraw−Hill
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glycolysis (gly-COLL-ih-sis) A series of anaerobic oxi-
dation reactions that break a glucose molecule into
two molecules of pyruvic acid and produce a small
amount of ATP.
glycoprotein (GLY-co-PRO-teen) A protein molecule
with a smaller carbohydrate covalently bonded to
it; found in mucus and the glycocalyx of cells, for
example.
glycosaminoglycan (GAG) (GLY-cose-am-ih-no-GLY-
can) A polysaccharide composed of modified sugars
with amino groups; the major component of a pro-
teoglycan. GAGs are largely responsible for the vis-
cous consistency of tissue gel and the stiffness of
cartilage.
glycosuria (GLY-co-SOOR-ee-uh) The presence of
glucose in the urine, typically indicative of a kid-
ney disease, diabetes mellitus, or other endocrine
disorder.
goblet cell A mucus-secreting gland cell, shaped
somewhat like a wineglass, found in the epithelia
of many mucous membranes. fig. 5.33
Golgi complex (GOAL-jee) An organelle composed
of several parallel cisternae, somewhat like a
stack of saucers, that modifies and packages
newly synthesized proteins and synthesizes car-
bohydrates. fig. 3.27
Golgi vesicle A membrane-bounded vesicle pinched
from the Golgi complex, containing its chemical

product; may be retained in the cell as a lysosome
or become a secretory vesicle that releases the
product by exocytosis.
gonad The ovary or testis.
gonadotropin (go-NAD-oh-TRO-pin) A pituitary
hormone that stimulates the gonads; specifically
FSH and LH.
G protein A protein of the plasma membrane that is
activated by a membrane receptor and, in turn,
opens an ion channel or activates an intracellular
physiological response; important in linking ligand-
receptor binding to second-messenger systems.
graded potential A variable change in voltage
across a plasma membrane, as opposed to the all-
or-none quality of an action potential.
gradient A difference or change in any variable,
such as pressure or chemical concentration, from
one point in space to another; provides a basis for
molecular movements such as gas exchange,
osmosis, and facilitated diffusion, and for bulk
movements such as blood flow and airflow.
granulocyte (GRAN-you-lo-site) Any of three types
of leukocytes (neutrophils, eosinophils, or
basophils) with prominent cytoplasmic granules.
granulosa cells Cells that form a stratified cuboidal
epithelium lining an ovarian follicle; source of
steroid sex hormones. fig. 28.14
gray matter A zone or layer of tissue in the central
nervous system where the neuron cell bodies, den-
drites, and synapses are found; forms the core of

the spinal cord, nuclei of the brainstem, basal nuclei
of the cerebrum, cerebral cortex, and cerebellar
cortex. fig. 14.6
gross anatomy Bodily structure that can be
observed without magnification.
growth factor A chemical messenger that stimu-
lates mitosis and differentiation of target cells
that have receptors for it; important in such
processes as fetal development, tissue mainte-
nance and repair, and hemopoiesis; sometimes a
contributing factor in cancer.
growth hormone (GH) A hormone of the anterior
pituitary gland with multiple effects on many tis-
sues, generally promoting tissue growth.
guanine A double-ringed nitrogenous base (purine)
found in DNA and RNA; one of the four bases of
the genetic code; complementary to cytosine in
the double helix of DNA. fig. 4.2
gyrus (JY-rus) A wrinkle or fold in the cortex of the
cerebrum or cerebellum.
H
hair cells Sensory cells of the cochlea, semicircular
ducts, utricle, and saccule, with a fringe of sur-
face microvilli that respond to the relative motion
of a gelatinous membrane at their tips; responsi-
ble for the senses of hearing and equilibrium.
hair follicle An oblique epidermal pit that contains
a hair and extends into the dermis or hypodermis.
half-life (T
1

⁄
2
) 1. The time required for one-half of a
quantity of a radioactive element to decay to a sta-
ble isotope (physical half-life) or to be cleared from
the body through a combination of radioactive
decay and physiological excretion (biological half-
life). 2. The time required for one-half of a quantity
of hormone to be cleared from the bloodstream.
haploid (n) In humans, having 23 unpaired chro-
mosomes instead of the usual 46 chromosomes in
homologous pairs; in any organism or cell, having
half the normal diploid number of chromosomes
for that species.
helper T cell A type of lymphocyte that performs a
central coordinating role in humoral and cellular
immunity; target of the human immunodefi-
ciency virus (HIV).
hematocrit (he-MAT-oh-crit) The percentage of
blood volume that is composed of erythrocytes.
hematoma (HE-muh-TOE-muh) A mass of clotted
blood in the tissues; forms a bruise when visible
through the skin.
heme (heem) The nonprotein, iron-containing pros-
thetic group of hemoglobin or myoglobin; oxygen
binds to its ferrous ion. fig. 18.10
hemocytoblast (HE-mo-SY-toe-blast) An undiffer-
entiated stem cell of the bone marrow that can
give rise to any of the formed elements of the
blood. fig. 18.4

hemoglobin (HE-mo-GLO-bin) The red gas- trans-
port pigment of an erythrocyte.
hemolysis (he-MOLL-ih-sis) The rupturing of ery-
throcytes from such causes as a hypotonic
medium, parasitic infection, or a complement
reaction.
hemopoiesis (HE-mo-poy-EE-sis) Production of any
of the formed elements of blood.
heparin (HEP-uh-rin) A polysaccharide secreted by
basophils and mast cells that inhibits blood clotting.
hepatic (heh-PAT-ic) Pertaining to the liver.
hepatic portal system A network of blood vessels
that connect capillaries of the intestines to capil-
laries (sinusoids) of the liver, thus delivering
newly absorbed nutrients directly to the liver.
hepatitis (HEP-uh-TY-tiss) Inflammation of the
liver.
heterozygous (HET-er-oh-ZY-gus) Having noniden-
tical alleles at the same gene locus of two homol-
ogous chromosomes.
hiatus (hy-AY-tus) An opening or gap, such as the
esophageal hiatus through the diaphragm.
high-density lipoprotein (HDL) A lipoprotein of the
blood plasma that is about 50% lipid and 50% pro-
tein; functions to transport phospholipids and cho-
lesterol from other organs to the liver for disposal.
A high proportion of HDL to low-density lipopro-
tein (LDL) is desirable for cardiovascular health.
hilum (HY-lum) A point on the surface of an organ
where blood vessels, lymphatic vessels, or nerves

enter and leave, usually marked by a depression
and slit; the midpoint of the concave surface of
any organ that is roughly bean-shaped, such as
the lymph nodes, kidneys, and lungs. Also called
the hilus. fig. 23.4
histamine (HISS-ta-meen) An amino acid derivative
secreted by basophils, mast cells, and some neurons;
functions as a paracrine secretion and neurotrans-
mitter to stimulate effects such as gastric secretion,
bronchoconstriction, and vasodilation. fig. 12.18
histological section A thin slice of tissue, usually
mounted on a slide and artificially stained to make
its microscopic structure more visible.
histology 1. The microscopic structure of tissues
and organs. 2. The study of such structure.
homeostasis (HO-me-oh-STAY-sis) The tendency of
a living body to maintain relatively stable internal
conditions in spite of greater changes in its exter-
nal environment.
homologous (ho-MOLL-uh-gus) 1. Having the same
embryonic or evolutionary origin but not neces-
sarily the same function, such as the scrotum and
labia majora. 2. Pertaining to two chromosomes
with identical structures and gene loci but not
necessarily identical alleles; each member of the
pair is inherited from a different parent.
homozygous (HO-mo-ZY-gus) Having identical alle-
les at the same gene locus of two homologous
chromosomes.
hormone A chemical messenger that is secreted

into the blood by an endocrine gland or isolated
gland cell and triggers a physiological response in
distant cells with receptors for it.
host cell Any cell belonging to the human body, as
opposed to foreign cells introduced to it by such
causes as infections and tissue transplants.
human Any species of primate classified in the
family Hominidae, characterized by bipedal loco-
motion, relatively large brains, and usually articu-
late speech; currently represented only by Homo
sapiens but including extinct species of Homo
and Australopithecus.
human chorionic gonadotropin (HCG) (COR-ee-ON-
ic) A hormone of pregnancy secreted by the
chorion that stimulates continued growth of the
corpus luteum and secretion of its hormones. HCG
in urine is the basis for pregnancy testing.
human immunodeficiency virus (HIV) A virus that
infects human helper T cells and other cells, sup-
presses immunity, and causes AIDS.
hyaline cartilage (HY-uh-lin) A form of cartilage
with a relatively clear matrix and fine collagen
fibers but no conspicuous elastic fibers or coarse
collagen bundles as in other types of cartilage.
G-9 Glossary
Saladin: Anatomy &
Physiology: The Unity of
Form and Function, Third
Edition
End Matter Glossary

© The McGraw−Hill
Companies, 2003
Glossary G-10
hyaluronic acid (HY-uh-loo-RON-ic) A gly-
cosaminoglycan that is particularly abundant in
connective tissues, where it becomes hydrated
and forms the tissue gel.
hydrogen bond A weak attraction between a
slightly positive hydrogen atom on one molecule
and a slightly negative oxygen or nitrogen atom
on another molecule, or between such atoms on
different parts of the same molecule; responsible
for the cohesion of water and the coiling of pro-
tein and DNA molecules, for example.
hydrolysis (hy-DROL-ih-sis) A chemical reaction
that breaks a covalent bond in a molecule by
adding an –OH group to one side of the bond and
–H to the other side, thus consuming a water
molecule. Compare dehydration synthesis.
hydrophilic (HY-dro-FILL-ic) Pertaining to mole-
cules that attract water or dissolve in it because
of their polar nature.
hydrophobic (HY-dro-FOE-bic) Pertaining to molecules
that do not attract water or dissolve in it because of
their nonpolar nature; such molecules tend to dis-
solve in lipids and other nonpolar solvents.
hydrostatic pressure The physical force generated
by a liquid such as blood or tissue fluid, as
opposed to osmotic and atmospheric pressures.
hydroxyl group (hy-DROCK-sil) A functional group

with the formula –OH found on many organic
molecules such as carbohydrates and alcohols.
hypercalcemia (HY-pur-cal-SEE-me-uh) An excess
of calcium ions in the blood.
hypercapnia (HY-pur-CAP-nee-uh) An excess of
carbon dioxide in the blood.
hyperextension A joint movement that increases the
angle between two bones beyond 180Њ. fig. 9.9
hyperglycemia (HY-pur-gly-SEE-me-uh) An excess
of glucose in the blood.
hyperkalemia (HY-pur-ka-LEE-me-uh) An excess of
potassium ions in the blood.
hypernatremia (HY-pur-na-TREE-me-uh) An excess
of sodium ions in the blood.
hyperplasia (HY-pur-PLAY-zhuh) The growth of a
tissue through cellular multiplication, not cellular
enlargement. Compare hypertrophy.
hyperpolarization A shift in the electrical potential
across a plasma membrane to a value more nega-
tive than the resting membrane potential, tending
to inhibit a nerve or muscle cell. Compare depolar-
ization.
hypersecretion Excessive secretion of a hormone or
other gland product; can lead to endocrine disor-
ders such as Cushing syndrome or gigantism, for
example.
hypertension Excessively high blood pressure; crite-
ria vary but it is often considered to be a condi-
tion in which systolic pressure exceeds 140 mmHg
or diastolic pressure exceeds 90 mmHg.

hyperthermia Excessively high core body tempera-
ture, as in heatstroke or fever.
hypertonic Having a higher osmotic pressure than
human cells or some other reference solution and
tending to cause osmotic shrinkage of cells.
hypertrophy (hy-PUR-tro-fee) The growth of a tis-
sue through cellular enlargement, not cellular
multiplication; for example, the growth of muscle
under the influence of exercise. Compare hyper-
plasia.
hypocalcemia (HY-po-cal-SEE-me-uh) A deficiency
of calcium ions in the blood.
hypocapnia (HY-po-CAP-nee-uh) A deficiency of
carbon dioxide in the blood.
hypodermis (HY-po-DUR-miss) A layer of connec-
tive tissue deep to the skin; also called superficial
fascia, subcutaneous tissue, or when it is pre-
dominantly adipose, subcutaneous fat.
hypoglycemia (HY-po-gly-SEE-me-uh) A deficiency
of glucose in the blood.
hypokalemia (HY-po-ka-LEE-me-uh) A deficiency
of potassium ions in the blood.
hyponatremia (HY-po-na-TREE-me-uh) A defi-
ciency of sodium ions in the blood.
hyposecretion Inadequate secretion of a hormone
or other gland product; can lead to endocrine dis-
orders such as diabetes mellitus or pituitary
dwarfism, for example.
hypothalamic thermostat (HY-po-thuh-LAM-ic) A
nucleus in the hypothalamus that monitors body

temperature and sends afferent signals to hypo-
thalamic heat-promoting or heat-losing centers
to maintain thermal homeostasis.
hypothalamus (HY-po-THAL-uh-mus) The inferior
portion of the diencephalon of the brain, forming
the walls and floor of the third ventricle and giv-
ing rise to the posterior pituitary gland; controls
many fundamental physiological functions such
as appetite, thirst, and body temperature and
exerts many of its effects through the endocrine
and autonomic nervous systems. fig. 14.12
hypothermia (HY-po-THUR-me-uh) A state of
abnormally low core body temperature.
hypothesis An informed conjecture that is capable
of being tested and potentially falsified by exper-
imentation or data collection.
hypotonic Having a lower osmotic pressure than
human cells or some other reference solution and
tending to cause osmotic swelling and lysis of cells.
hypovolemic shock (HY-po-vo-LEE-mic) Insuffi-
cient cardiac output resulting from a drop in
blood volume. See also shock.
hypoxemia (HY-pock-SEE-me-uh) A deficiency of
oxygen in the bloodstream.
hypoxia (hy-POCK-see-uh) A deficiency of oxygen
in any tissue.
I
immune system A population of cells, including
leukocytes and macrophages, that occur in most
organs of the body and protect against foreign

organisms, some foreign chemicals, and cancerous
or other aberrant host cells.
immunity The ability to ward off a specific infection
or disease, usually as a result of prior exposure and
the body’s production of antibodies or lympho-
cytes against a pathogen. Compare resistance.
immunoglobulin (IM-you-no-GLOB-you-lin) See
antibody.
implantation The attachment of a conceptus to the
endometrium of the uterus.
inclusion Any visible object in the cytoplasm of a cell
other than an organelle or cytoskeletal element;
usually a foreign body or a stored cell product, such
as a virus, dust particle, lipid droplet, glycogen
granule, or pigment.
infarction (in-FARK-shun) 1. The sudden death of
tissue from a lack of blood perfusion; also called
an infarct. 2. An area of necrotic tissue produced
by this process.
inferior Lower than another structure or point of
reference from the perspective of anatomical
position; for example, the stomach is inferior to
the diaphragm.
inflammation (IN-fluh-MAY-shun) A complex of
tissue responses to trauma or infection serving to
ward off a pathogen and promote tissue repair;
recognized by the cardinal signs of redness, heat,
swelling, and pain.
infundibulum (IN-fun-DIB-you-lum) Any funnel-
shaped passage or structure, such as the distal

portion of the uterine tube and the stalk that
attaches the pituitary gland to the hypothalamus.
inguinal (IN-gwih-nul) Pertaining to the groin.
inhibin A hormone produced by the testes and
ovaries that inhibits the secretion of FSH.
inhibitory postsynaptic potential (IPSP) Hyperpo-
larization of a postsynaptic neuron in response to
a neurotransmitter, making it less likely to reach
threshold and fire.
innervation (IN-ur-VAY-shun) The nerve supply to
an organ.
insertion The point at which a muscle attaches to
another tissue (usually a bone) and produces
movement, opposite from its stationary origin;
the origin and insertion of a given muscle some-
times depend on what muscle action is being
considered. Compare origin.
inspiration Inhaling.
insulin (IN-suh-lin) A hormone produced by ␤ cells
of the pancreatic islets in response to a rise in
blood glucose concentration; accelerates glucose
uptake and metabolism by most cells of the body,
thus lowering blood glucose concentration.
integral (transmembrane) protein A protein that
extends through a plasma membrane and contacts
both the extracellular and intracellular fluid. fig. 3.7
integration A process in which a neuron receives
input from multiple sources and their combined
effects determine its output; the cellular basis of
information processing by the nervous system.

integumentary system (in-TEG-you-MEN-tah-ree)
An organ system consisting of the skin, cutaneous
glands, hair, and nails.
interatrial septum (IN-tur-AY-tree-ul) The wall
between the atria of the heart.
intercalated disc (in-TUR-kuh-LAY-ted) A complex
of fascia adherens, gap junctions, and desmo-
somes that join two cardiac muscle cells end to
end, microscopically visible as a dark line which
helps to histologically distinguish this muscle
type; functions as a mechanical and electrical link
between cells. fig. 19.11
intercellular Between cells.
intercostal (IN-tur-COSS-tul) Between the ribs, as in
the intercostal muscles, arteries, veins, and nerves.
interdigitate (IN-tur-DIDJ-ih-tate) To fit together
like the fingers of two folded hands; for example,
at the dermal-epidermal boundary, intercalated
discs of the heart, and pedicels of the podocytes in
the kidney. fig. 23.9
Saladin: Anatomy &
Physiology: The Unity of
Form and Function, Third
Edition
End Matter Glossary
© The McGraw−Hill
Companies, 2003
interleukin (IN-tur-LOO-kin) A hormonelike chemi-
cal messenger from one leukocyte to another,
serving as a means of communication and coordi-

nation during immune responses.
interneuron (IN-tur-NEW-ron) A neuron that is
contained entirely in the central nervous system
and, in the path of signal conduction, lies any-
where between an afferent pathway and an
efferent pathway.
interosseous membrane (IN-tur-OSS-ee-us) A
fibrous membrane that connects the radius to the
ulna and the tibia to the fibula along most of the
shaft of each bone. fig. 8.33
interphase That part of the cell cycle between one
mitotic phase and the next, from the end of
cytokinesis to the beginning of the next prophase.
interstitial (IN-tur-STISH-ul) 1. Pertaining to the
extracellular spaces in a tissue. 2. Located
between other structures, as in the interstitial
cells of the testis.
interstitial fluid Fluid in the interstitial spaces of a
tissue, also called tissue fluid.
intervertebral disc A cartilaginous pad between the
bodies of two adjacent vertebrae.
intracellular Within a cell.
intracellular fluid (ICF) The fluid contained in the
cells; one of the major fluid compartments.
intravenous (I.V.) 1. Present or occurring within a
vein, such as an intravenous blood clot. 2. Intro-
duced directly into a vein, such as an intravenous
injection or I.V. drip.
intrinsic (in-TRIN-sic) 1. Arising from within, such as
intrinsic blood-clotting factors; endogenous. 2.

Fully contained within an organ, such as the intrin-
sic muscles of the hand and eye. Compare extrinsic.
intrinsic factor A secretion of the gastric glands
required for the intestinal absorption of vitamin
B
12
. Hyposecretion of intrinsic factor leads to per-
nicious anemia.
in vitro (in VEE-tro) In a laboratory container;
removed from the body and observed in isolation
(Latin, in glass).
in vivo (in VEE-vo) In the living state; in the body
(Latin, in life).
involuntary Not under conscious control, including
tissues such as smooth and cardiac muscle and
events such as reflexes.
involution (IN-vo-LOO-shun) Shrinkage of a tissue or
organ by autolysis, such as involution of the thymus
after childhood and of the uterus after pregnancy.
ion A chemical particle with unequal numbers of
electrons or protons and consequently a net neg-
ative or positive charge; it may have a single
atomic nucleus as in a sodium ion or a few atoms
as in a bicarbonate ion, or it may be a large mole-
cule such as a protein.
ionic bond The force that binds a cation to an anion.
ionizing radiation High-energy electromagnetic rays
that eject electrons from atoms or molecules and
convert them to ions, frequently causing cellular
damage; for example, X rays and gamma rays.

ipsilateral (IP-sih-LAT-ur-ul) On the same side of
the body, as in reflex arcs in which a muscular
response occurs on the same side of the body as
the stimulus. Compare contralateral.
ischemia (iss-KEE-me-uh) Insufficient blood flow to
a tissue, typically resulting in metabolite accumu-
lation and sometimes tissue death.
isometric contraction A muscle contraction in
which internal tension rises but the muscle does
not shorten.
isotonic Having the same osmotic pressure as human
cells or some other reference solution.
isotonic contraction A muscle contraction in which
the muscle shortens and moves a load while its
internal tension remains constant.
J
jaundice (JAWN-diss) A yellowish color of the skin,
corneas, mucous membranes, and body fluids due
to an excessive concentration of bilirubin; usually
indicative of a liver disease, obstructed bile secre-
tion, or hemolytic disease.
K
ketone (KEE-tone) Any organic compound with a
carbonyl (CϭO) group covalently bonded to two
other carbons.
ketone bodies Certain ketones (acetone, ace-
toacetic acid, and ␤-hydroxybutyric acid) pro-
duced by the incomplete oxidation of fats, espe-
cially when fats are being rapidly catabolized. See
also ketosis.

ketonuria (KEE-toe-NEW-ree-uh) The abnormal
presence of ketones in the urine as an effect of
ketosis.
ketosis (kee-TOE-sis) An abnormally high concen-
tration of ketone bodies in the blood, occurring in
pregnancy, starvation, diabetes mellitus, and
other conditions; tends to cause acidosis and to
depress the nervous system.
kilocalorie The amount of heat energy needed to
raise the temperature of 1 kg of water by 1ЊC;
1,000 calories. Also called a Calorie or large calo-
rie.
kinase Any enzyme that adds an inorganic phos-
phate (P
i
) group to another organic molecule.
Also called a phosphokinase.
L
labium (LAY-bee-um) A lip, such as those of the
mouth and the labia majora and minora of the
vulva.
lactation The secretion of milk.
lactic acid A small organic acid produced as an end
product of the anaerobic fermentation of pyruvic
acid; a contributing factor in muscle fatigue.
lacuna (la-CUE-nuh) A small cavity or depression in a
tissue such as bone, cartilage, and the erectile tissues.
lamella (la-MELL-uh) A little plate, such as the
lamellae of bone. fig. 7.4
lamina (LAM-ih-nuh) A thin layer, such as the lam-

ina of a vertebra or the lamina propria of a
mucous membrane. fig. 8.22
lamina propria (PRO-pree-uh) A thin layer of areo-
lar tissue immediately deep to the epithelium of a
mucous membrane. fig. 5.33
larynx (LAIR-inks) A cartilaginous chamber in the
neck containing the vocal cords; the voicebox.
latent period The interval between a stimulus and
response, especially in the action of nerve and
muscle cells.
lateral Away from the midline of an organ or
median plane of the body; toward the side. Com-
pare medial.
law A verbal or mathematical description of a pre-
dictable natural phenomenon or of the relation-
ships between variables; for example, Boyle’s law
and the second law of thermodynamics.
law of mass action A law that states that the speed
and direction of a reversible chemical reaction is
determined by the relative quantities of the reac-
tants. A reversible reaction A ϩ B ↔ C ϩ D pro-
ceeds left to right if the quantity of A ϩ B is
greater than the quantity of C ϩ D and right to
left if the latter is greater. This principle governs
such reactions as the binding and dissociation of
oxygen and hemoglobin.
leader sequence A sequence of bases in mRNA that
is not translated to protein but serves as a bind-
ing site for a ribosome.
length-tension relationship A law that relates the

tension generated by muscle contraction to the
length of the muscle fiber prior to stimulation; it
shows that the greatest tension is generated
when the fiber exhibits an intermediate degree of
stretch before stimulation.
lesion A circumscribed zone of tissue injury, such as
a skin abrasion or myocardial infarction.
leukocyte (LOO-co-site) A white blood cell.
leukotrienes (LOO-co-TRY-eens) Eicosanoids that
promote allergic and inflammatory responses such
as vasodilation and neutrophil chemotaxis; secreted
by basophils, mast cells, and damaged tissues.
libido (lih-BEE-do) Sex drive.
ligament A cord or band of tough collagenous tis-
sue binding one organ to another, especially one
bone to another, and serving to hold organs in
place; for example, the cruciate ligaments of the
knee, broad ligament of the uterus, and falciform
ligament of the liver.
ligand (LIG-and, LY-gand) A chemical that binds
reversibly to a receptor site on a protein, such as
a neurotransmitter that binds to a membrane
receptor or a substrate that binds to an enzyme.
ligand-regulated gate A channel protein in a
plasma membrane that opens or closes when a
ligand binds to it, enabling the ligand to deter-
mine when substances can enter or leave the cell.
light microscope (LM) A microscope that produces
images with visible light.
linea (LIN-ee-uh) An anatomical line, such as the

linea alba.
lingual (LING-gwul) Pertaining to the tongue, as in
lingual papillae.
lipase (LY-pace) An enzyme that hydrolyzes a
triglyceride into fatty acids and glycerol.
lipid A hydrophobic organic compound composed
mainly of carbon and a high ratio of hydrogen to
oxygen; includes fatty acids, fats, phospholipids,
steroids, and prostaglandins.
lipoprotein (LIP-oh-PRO-teen) A protein-coated lipid
droplet in the blood plasma or lymph, serving as a
means of lipid transport; for example, chylomicrons
and the high- and low-density lipoproteins.
load 1. To pick up a gas for transport in the blood-
stream. 2. The resistance acted upon by a muscle.
G-11 Glossary