The Cardiovascular System: Blood Vessels
(Some questions have more than one correct answer. Select the best
answer or answers from the choices given.)
Which statement does not accurately describe veins?
less elastic tissue and smooth muscle than arteries,
more ﬁbrous tissue than arteries,
most veins in the extremities
always carry deoxygenated blood.
Smooth muscle in the blood vessel wall
is found primarily
in the tunica intima,
is mostly circularly arranged,
is most abundant in veins,
is usually innervated by the
parasympathetic nervous system.
is inversely proportional to the length of the
increases in anemia,
decreases in polycythemia,
is inversely related to the diameter of the arterioles.
Which of the following can lead to decreased venous return
of blood to the heart?
an increase in blood volume,
increase in venous pressure,
damage to the venous valves,
increased muscular activity.
Arterial blood pressure increases in response to
increasing heart rate,
rising blood volume,
all of these.
Which of the following would
result in the dilation of the
feeder arterioles and opening of the precapillary sphincters
in systemic capillary beds?
a decrease in local tissue O
an increase in local tissue CO
a local increase in
a local increase in pH.
Te structure of a capillary wall diﬀers from that of a vein or an
it has two tunics instead of three,
is less smooth muscle,
it has a single tunic—only the tunica
none of these.
Te baroreceptors in the carotid sinus and aortic arch are
a decrease in CO
changes in arterial pressure,
a decrease in O
all of these.
Te myocardium receives its blood supply directly from the
Blood ﬂow in the capillaries is steady despite the rhythmic
pumping of the heart because of the
elasticity of the large
small diameter of capillaries,
thin walls of the
Using the letters from column B, match the artery descriptions in
column A. (Note that some require more than a single choice.)
unpaired branch of
second branch of
branch of internal
branch of external
origin of femoral
right common carotid
leF common carotid
Which of the following do not drain directly into the inferior
inferior phrenic veins,
inferior mesenteric vein,
Suppose that at a given point along a capillary, the following
forces exist: capillary hydrostatic pressure (HP
30 mm Hg,
interstitial ﬂuid hydrostatic pressure (HP
0 mm Hg, capillary
colloid osmotic pressure (OP
25 mm Hg, and interstitial
ﬂuid colloid osmotic pressure (OP
2 mm Hg. Te net
ﬁltration pressure at this point in the capillary is
3 mm Hg,
3 mm Hg,
7 mm Hg,
7 mm Hg.
Short Answer Essay Questions
How is the anatomy of capillaries and capillary beds well suited to
Distinguish between elastic arteries, muscular arteries, and arterioles
relative to location, histology, and functional adaptations.
Write an equation showing the relationship between peripheral
resistance, blood ﬂow, and blood pressure.
(a) Deﬁne blood pressure. Diﬀerentiate between systolic and
diastolic blood pressure. (b) What is the normal blood pressure
value for an adult?
Describe the neural mechanisms responsible for controlling
Explain the reasons for the observed changes in blood ﬂow
velocity in the diﬀerent regions of the circulation.
How does the control of blood ﬂow to the skin for the purpose of
regulating body temperature diﬀer from the control of nutrient
blood ﬂow to skin cells?
Describe neural and chemical (both systemic and local) eﬀects
exerted on the blood vessels when you are ﬂeeing from a mugger.
(Be careful, this is more involved than it appears at ﬁrst glance.)
How are nutrients, wastes, and respiratory gases transported to
and from the blood and tissue spaces?
(a) What blood vessels contribute to the formation of the hepatic
portal circulation? (b) Why is a portal circulation a “strange”
Physiologists oFen consider capillaries and postcapillary
venules together. (a) What functions do these vessels share?
(b) Structurally, how do they diﬀer?
and Clinical Application
Mrs. Johnson is brought to the emergency room aFer being
involved in an auto accident. She is hemorrhaging and has a
rapid, thready pulse, but her blood pressure is still within normal
limits. Describe the compensatory mechanisms that act to
maintain her blood pressure in the face of blood loss.
A 60-year-old man is unable to walk more than 100 yards without
experiencing severe pain in his leF leg; the pain is relieved by
resting for 5–10 minutes. He is told that the arteries of his leg are
becoming occluded with fatty material and is advised to have the
sympathetic nerves serving that body region severed. Explain
how such surgery might help to relieve this man’s problem.
Your friend Joanie, who knows little about science, is reading a
magazine article about a patient who had an “aneurysm at the base
of his brain that suddenly grew much larger.” Te surgeons’ ﬁrst goal
was to “keep it from rupturing,” and the second goal was to “relieve
±racing the blood from the heart to the right hand, we ﬁnd
that blood leaves the heart and passes through the aorta, the
right subclavian artery, the axillary and brachial arteries, and
through either the radial or ulnar artery to arrive at the hand.
Which artery is missing from this sequence?
right common carotid.