NAME ____________________________________
EXERCISE
LAB TIME/DATE _______________________
32
Anatomy of Blood Vessels
Microscopic Structure of the Blood Vessels
1. Cross-sectional views of an artery and of a vein are shown here. Identify each; and on the lines to the sides, note the structural details that enabled you to make these identifications:
artery
vein
(vessel type)
(vessel type)
open, circular lumen
somewhat collapsed lumen
(a)
(a)
thick tunica media
thinner tunica media
(b)
(b)
Now describe each tunic more fully by selecting its characteristics from the key below and placing the appropriate key letters on the answer lines.
Tunica intima a, c, f
Tunica media d, e
Tunica externa b
Key:
a.
b.
c.
d.
innermost tunic most superficial tunic thin tunic of capillaries especially thick in elastic arteries
e.
f.
contains smooth muscle and elastin has a smooth surface to decrease resistance to blood flow
2. Why are valves present in veins but not in arteries? The high blood pressure in arteries propels the blood through them. The blood pressure in veins is low and often the blood is flowing against gravity. Valves prevent backflow.
3. Name two events occurring within the body that aid in venous return.
Skeletal muscle “milking action”
and changes in thoracic cavity pressure during breathing.
4. Why are the walls of arteries proportionately thicker than those of the corresponding veins? Arteries must withstand high pressure and pressure fluctuations. Veins are low-pressure vessels.
Major Systemic Arteries and Veins of the Body
5. Use the key on the right to identify the arteries or veins described on the left. d 1. the arterial system has one of these; the venous system has two
i
2. these arteries supply the myocardium
r
,
z
o
3. two paired arteries serving the brain
4. longest vein in the lower limb
Key: a.
anterior tibial
b.
basilic
c.
brachial
d.
brachiocephalic
e.
celiac trunk
f.
cephalic
k
5. artery on the dorsum of the foot checked after leg surgery
g.
common carotid
j
6. serves the posterior thigh
h.
common iliac
t
7. supplies the diaphragm
i.
coronary
c
8. formed by the union of the radial and ulnar veins
j.
deep artery of the thigh k.
dorsalis pedis external carotid
b
, f
9. two superficial veins of the arm
w
10. artery serving the kidney
l.
p
11. veins draining the liver
m. femoral
q
12. artery that supplies the distal half of the large intestine
s
13. drains the pelvic organs
m
14. what the external iliac artery becomes on entry into the thigh
n.
fibular
o.
great saphenous
p.
hepatic
q.
inferior mesenteric
c
15. major artery serving the arm
r.
internal carotid
y
16. supplies most of the small intestine
s.
internal iliac
h
17. join to form the inferior vena cava
t.
phrenic
e
18. an arterial trunk that has three major branches, which run to the liver, spleen, and stomach
u.
posterior tibial
v.
radial
19. major artery serving the tissues external to the skull
w. renal
l a v
, n
,
u
20. three veins serving the leg
21. artery generally used to take the pulse at the wrist
x.
subclavian
y.
superior mesenteric
z.
vertebral
6. What is the function of the cerebral arterial circle (circle of Willis)? Provides an alternate set of pathways for blood to reach brain tissue in case of impaired blood flow anywhere in the system.
7. The anterior and middle cerebral arteries arise from the internal carotid the cerebral hemispheres
artery. They serve
of the brain.
8. Trace the pathway of a drop of blood from the aorta to the left occipital lobe of the brain, noting all structures through which it flows. Aorta → subclavian artery → vertebral artery → basilar artery → posterior cerebral artery → occipital brain tissue.
