Review Questions: Ch. 21 - The Circulatory System 3 - Blood Vessels

What's wrong with this statement? In a few unusual cases, one or more arteries of the cerebral arterial circle are lacking.

One or more arteries of the circle are missing in 80% of people.

There are certain similarities between the arteries of the hand and foot. What arteries of the wrist and hand are most comparable in arrangement and function to the arcuate artery and deep plantar arch of the foot?

The deep palmar arch and superficial palmar arch of the hand are comparable to the arcuate artery and deep plantar arch of the foot.

What's wrong with this statement? The smooth muscle of the tunica media of a large vessel is nourished mainly by the diffusion of nutrients from blood in the vessel lumen.

The tunica media is nourished mainly by capillaries of the vasa vasorum.

What's wrong with this statement? The pancreas and spleen receive their blood supply mainly from the superior mesenteric artery.

They receive blood from the celiac trunk.

True or false: Arteries to the ovaries and testes originate relatively high in the abdominal cavity, near the kidneys.

True The gonadal arteries, which supply the ovaries and testes, are branches of the abdominal aorta coming off just inferior to the superior mesenteric artery.

Why would venous valves be unnecessary in the jugular veins of the neck?

Venous valves aren't necessary in the jugular veins because the blood as long as a person is standing or sitting, blood in these veins flows downward by the pull of gravity. No valves are needed to prevent it from flowing upward against gravity.

Which of the following arteries does not contain blood that is destined to circulate through the brain before returning to the heart? a) Superficial temporal artery b) Anterior communicating artery c) Internal carotid arteries d) Vertebral arteries e) Basilar artery

a) Superficial temporal artery The superficial temporal artery supplies the scalp, not the brain.

A blood vessel adapted to withstand great fluctuations in blood pressure would be expected to have a) an elastic tunica media. b) a thick tunica interna. c) one-way valves. d) a flexible endothelium. e) a rigid tunica media.

a) an elastic tunica media.

Most of the blood supply to the brain comes from a ring of arterial anastomoses called the cerebral __________ circle.

arterial The cerebral arterial circle receives blood from the internal carotid and basilar arteries. Most people lack one or more of its components; only 20% have a complete arterial circle. Knowledge of the distribution of the arteries arising from the circle is crucial for understanding the effects of blood clots, aneurysms, and strokes on brain function. The anterior and posterior cerebral arteries and the middle cerebral artery provide the most significant blood supplies to the cerebrum.

A cold, pale hand could be a sign of a blockage of blood flow in the __________ artery. a) femoral b) axillary c) basilar d) saphenous e) basilic

b) axillary The axillary artery gives way to the brachial artery, which branches into almost all of the arteries that supply the upper limb. The basilic is a vein, and the femoral and saphenous vessels are in the lower limb. The basilar artery is in the cranial cavity.

Plasma solutes enter the tissue fluid most easily from a) continuous capillaries. b) fenestrated capillaries. c) arteriovenous anastomoses. d) collateral vessels. e) venous anastomoses.

b) fenestrated capillaries.

The connection to the placenta has to be redirected after birth. To accomplish this redirection, the ductus venosus constricts and forces blood to flow through the __________ instead of directly into the inferior vena cava. a) kidney b) liver c) heart d) spleen

b) liver One fetal shunt, called the ductus venosus, bypasses the liver, which is not very functional before birth. This is a vein; blood returning from the placenta enters the fetus through the umbilical vein and flows into the ductus venosus. The ductus venosus then empties into the inferior vena cava. After birth, the ductus venosus constricts, and blood is forced to flow through the liver. The ductus venosus leaves a fibrous remnant, the ligamentum venosum, on the inferior surface of the liver.

All of the following blood vessels except the _______ are located in the upper limb. a) cephalic vein b) small saphenous vein c) brachial artery d) circumflex humeral arteries e) metacarpal arteries

b) small saphenous vein

Intestinal blood flows into the liver by way of a) the superior mesenteric vein. b) the hepatic portal vein. c) the abdominal aorta. d) the hepatic sinusoids. e) the hepatic veins.

b) the hepatic portal vein.

Of the following, the most accessible and frequently used vessel for drawing a patient's blood is a) the radial vein. b) the median cubital vein. c) the external carotid artery. d) the radial artery. e) the ulnar artery.

b) the median cubital vein.

To get from the posterior tibial vein to the femoral vein, blood flows through a) the anterior tibial vein. b) the popliteal vein. c) the internal iliac vein. d) the great saphenous vein. e) the basilic vein.

b) the popliteal vein.

Blood islands first form in the embryonic a) spleen. b) yolk sac. c) placenta. d) liver. e) red bone marrow.

b) yolk sac.

The major superficial veins of the arm are the _______ on the medial side and _______ on the lateral side.

basilic, cephalic

Blood normally flows into a capillary bed from a) a distributing artery. b) a conducting artery. c) a metarteriole. d) a thoroughfare channel. e) a venule.

c) a metarteriole.

Swelling of the hand could be caused by a thrombosis in the __________ vein. a) popliteal b) internal jugular c) median antebrachial d) small saphenous e) dorsal venous arch

c) median antebrachial The medial antebrachial vein is found in the middle of the forearm. It drains blood from the hand and forearm. The dorsal venous arch and saphenous veins are in the lower limb. There is no basilar vein.

A cold, pale foot could be a sign of a blockage of blood flow in the __________ artery. a) basilar b) basilic c) popliteal d) axillary e) saphenous

c) popliteal The popliteal artery branches into the anterior and posterior tibial arteries. The anterior and posterior tibial arteries eventually branch into the dorsal and plantar arteries of the foot. There is no basilic artery; it is a vein. The saphenous vessels are veins in the lower limb. The basilar artery is in the cranial cavity.

To get from the posterior tibial vein to the femoral vein, blood flows through the __________. a) basilic vein b) internal iliac vein c) popliteal vein d) great saphenous vein e) anterior tibial vein

c) popliteal vein The popliteal vein is found in the posterior knee, which is between the lower leg and the thigh.

The pressure sensors in the major arteries near the head are called _______.

carotid sinuses

Most of the blood supply to the brain comes from a ring of arterial anastomoses called the _______.

cerebral arterial circle

Carotid and aortic bodies are called _______ because they respond to changes in blood chemistry.

chemoreceptors

The two _______ veins unite like an upside-down Y to form the inferior vena cava.

common iliac

The capillaries of skeletal muscles are of the structural type called _______.

continuous capillaries

Intestinal blood flows into the liver by way of the _________. a) abdominal aorta b) hepatic sinusoids c) hepatic veins d) superior mesenteric vein e) hepatic portal vein

e) hepatic portal vein The hepatic portal vein bypasses the inferior vena cava to bring intestinal blood to the liver so nutrients, minerals, and toxins can be processed before the blood is returned into the general circulation. After the liver, the blood is then delivered to the inferior vena cava.

The epithelium that lines the inside of a blood vessel is called _______.

endothelium

Filtration pores are characteristic of _______ capillaries.

fenestrated

The two largest veins that empty into the right atrium are the _______ and _______.

superior vena cava, inferior vena cava

Movement across the capillary endothelium by the uptake and release of fluid droplets is called _______.

transcytosis

Having studied branches of the abdominal aorta and pelvic vessels, can you now identify any of the unlabeled arteries in the magnetic resonance angiogram in figure 21.3?

In addition to the labeled arteries (abdominal aorta and common iliac arteries), one should be able to identify the renal arteries, inferior mesenteric artery, internal and external iliac arteries, and femoral arteries in this photo.

Correctly label the following structures of pulmonary circulation. Pulmonary vein Pulmonary artery Alveolar capillaries Alveolar sacs

In both lungs, the lobar arteries lead ultimately to small basketlike capillary beds that surround the pulmonary alveoli (air sacs). This is where the blood unloads CO2 and picks up O2. After leaving the alveolar capillaries, the pulmonary blood flows into venules and veins, ultimately leading to the main pulmonary veins that exit the lung at the hilum. The left atrium of the heart receives two pulmonary veins on each side.

Correctly label the following arteries of the abdomen and pelvic region. Celiac trunk Suprarenal arteries Superior mesenteric artery Renal artery Lumbar arteries Gonadal artery Inferior mesenteric artery

In order from superior to inferior, the branches off the abdominal aorta are as follows. The inferior phrenic arteries supply the inferior surface of the diaphragm. Each issues two or three small superior suprarenal arteries to the ipsilateral adrenal (supra renal) gland. The celiac trunk supplies the upper abdominal viscera. The superior mesenteric artery supplies the intestines. The middle suprarenal arteries arise laterally from the aorta and supply the adrenal glands. The renal arteries supply the kidneys and issue a small inferior supra renal artery to each adrenal gland. The gonadal arteries are long, slender arteries that arise from the midabdominal aorta and descend along the posterior body wall to the female pelvic cavity or male scrotum. The inferior mesenteric artery supplies the distal end of the large intestine. The lumbar arteries arise from the lower aorta in four pairs. The median sacral artery supplies the sacrum and coccyx. The common iliac arteries arise as the aorta forks at its inferior end.

What's wrong with this statement? The superior vena cava begins where the two subclavian veins meet.

It is formed by the union of the two brachiocephalic veins.

Place the following vessels in the order through which blood would pass, beginning with blood entering the systemic circuit after exiting the heart. External iliac vein Femoral artery Inferior vena cava Aorta Popliteal vein Common iliac vein Popliteal artery Common iliac artery Femoral vein Eternal iliac artery

1) Aorta 2) Common iliac artery 3) External iliac artery 4) Femoral artery 5) Popliteal artery 6) Popliteal vein 7) Femoral vein 8) External iliac vein 9) Common iliac vein 10) Inferior vena cava The passageways for blood in the right portion of the lower extremity include the movement of blood from the heart through the ascending aorta, to the aortic arch, down the descending aorta to the abdominal aorta, through the common iliac, external iliac, femoral, popliteal, and posterior tibial arteries before passing through capillaries and returning through the posterior tibial, popliteal, femoral, external iliac, and common iliac veins to the inferior vena cava.

Why could a choke hold (a tight grip around the neck) cause a person to pass out? What arteries would be involved?

A choke hold can compress the carotid arteries and cause cerebral ischemia.

What's wrong with this statement? Arterial blood cannot get to the veins without first flowing through capillaries.

Arteriovenous anastomoses allow blood to bypass the capillaries.

Why is it better to have baroreceptors in the carotid sinus rather than in some other location such as the abdominal aorta or common iliac arteries?

Baroreceptors must monitor blood pressure especially to ensure homeostatic blood flow to the brain. They would not serve this purpose well if they were located at a point such as the abdominal aorta or common iliac arteries; an adequate or even high blood pressure in these sites may result simply from gravity drawing blood downward, and would not necessarily mean that there was adequate pressure in the cerebral circulation or other points above the heart. If the blood pressure above the heart is adequate, however, it is almost certain to be adequate in the lower limbs and it is likely that the brain is also being adequately perfused.

Suppose a posterior tibial vein was obstructed by thrombosis. Describe one or more alternative routes by which blood from the foot could get to the common iliac vein.

Blood from the foot could still reach the common iliac vein by alternative routes: both the anterior tibial veins and small saphenous vein lead to the femoral vein and then the external iliac vein. The great saphenous vein also drains blood from the foot into the femoral vein.

What's wrong with this statement? From the time blood leaves the heart to the time it returns, it always passes through only one capillary bed.

Blood sometimes passes through portal systems (two capillary beds) or anastomoses (bypassing capillaries).

Correctly label the arteries of the cerebral blood supply.

Blood supply to the brain is so critical that it is furnished by several arterial anastomoses, especially an array of arteries called the cerebral arterial circle (circle of Willis), which surrounds the pituitary gland and optic chiasm. The circle receives blood from the internal carotid and basilar arteries. Two posterior cerebral arteries arise from the basilar artery and sweep posteriorly to the rear of the brain, serving the inferior and medial regions of the temporal and occipital lobes as well as the midbrain and thalamus. Two anterior cerebral arteries arise from the internal carotids, travel anteriorly, and then arch posteriorly over the corpus callosum as far as the posterior limit of the parietal lobe. The single anterior communicating artery is a short anastomosis between the right and left anterior cerebral arteries. The two posterior communicating arteries are small anastomoses between the posterior cerebral and internal carotid arteries.

Correctly label the following major systemic veins. Brachiocephalic vein Subclavian vein Axillary vein Cephalic vein Basilic vein Median ante brachial vein

Both superficial and deep veins drain the upper limb, ultimately leading to axillary and subclavian veins. The superficial veins are often externally visible and are larger in diameter and carry more blood than the deep veins. The dorsal venous network is a plexus of veins that empties into the major superficial veins of the forearm, the cephalic and basilic. The median cubital vein is a short anastomosis between the cephalic and basilic veins. The median antebrachial vein drains a network of blood vessels in the hand called the superficial palmar venous network. The axillary vein forms by the union of the brachial and basilic veins. At the lateral margin of the first rib, it changes name to the subclavian vein. The subclavian vein continues into the shoulder where it meets the internal jugular vein of the neck. There it becomes the brachiocephalic vein. The right and left brachiocephalics converge and form the superior vena cava, which empties into the right atrium of the heart.

Correctly label the following major systemic veins. Superior vena cava Brachial veins Radial veins Ulnar veins Venous palmar arches

Both superficial and deep veins drain the upper limb, ultimately leading to axillary and subclavian veins. The superficial veins are often externally visible and are larger in diameter and carry more blood than the deep veins. The dorsal venous network is a plexus of veins that empties into the major superficial veins of the forearm, the cephalic and basilic. The median cubital vein is a short anastomosis between the cephalic and basilic veins. The median antebrachial vein drains a network of blood vessels in the hand called the superficial palmar venous network. The axillary vein forms by the union of the brachial and basilic veins. At the lateral margin of the first rib, it changes name to the subclavian vein. The subclavian vein continues into the shoulder where it meets the internal jugular vein of the neck. There it becomes the brachiocephalic vein. The right and left brachiocephalics converge and form the superior vena cava, which empties into the right atrium of the heart.

Correctly label the following veins of the upper limbs. Subclavian vein Axillary vein Cephalic vein Basilic vein Brachial vein Median cubital vein

Both superficial and deep veins drain the upper limb, ultimately leading to axillary and subclavian veins. The superficial veins are often externally visible and are larger in diameter and carry more blood than the deep veins. The dorsal venous network is a plexus of veins that empties into the major superficial veins of the forearm, the cephalic and basilic. The median cubital vein is a short anastomosis between the cephalic and basilic veins. The median antebrachial vein drains a network of blood vessels in the hand called the superficial palmar venous network. The axillary vein forms by the union of the brachial and basilic veins. At the lateral margin of the first rib, it changes name to the subclavian vein. The subclavian vein continues into the shoulder where it meets the internal jugular vein of the neck. There it becomes the brachiocephalic vein. The right and left brachiocephalics converge and form the superior vena cava, which empties into the right atrium of the heart.

What's wrong with this statement? Since blood capillaries have no muscle, the blood flow through them is constant; it can't be increased or decreased from moment to moment.

Capillary blood flow is regulated by precapillary sphincters.

Drag each image on the left to the type of vessel it represents on the right. Large vein Medium vein Venule Conducting artery Distributing artery Arteriole

Conducting arteries are the biggest. They have two layers of elastic tissue called the external and internal elastic lamina, but microscopically it is difficult to distinguish from the elastic tissue of the tunica media. Distributing arteries are smaller branches that typically have up to 40 layers of smooth muscle constituting about three-quarters of the wall thickness. Resistance (small) arteries exhibit up to 25 layers of smooth muscle and relatively little elastic tissue. Compared to large postcapillary venulesarteries, they have a thicker tunica media in proportion to the lumen. The smallest of these arteries are called arterioles, which have very little tunica externa. Continuous capillaries occur in most tissues, such as skeletal muscle. Their endothelial cells, held together by tight junctions, form a continuous tube. Postcapillary venules are the smallest of the veins, which receive blood from capillaries directly or by way of the distal ends of the thoroughfare channels. Muscular venules receive blood from the postcapillary venules, which have a tunica media of one or two layers of smooth muscle and a thin tunica externa. Medium veins have a tunica interna with an endothelium, basement membrane, loose connective tissue, and sometimes a thin internal elastic lamina. Large veins have some smooth muscle in all three tunics. They have a relatively thin tunica media with only a moderate amount of smooth muscle; the tunica externa is the thickest layer and contains longitudinal bundles of smooth muscle.

What's wrong with this statement? Most blood from the brain drains down the external jugular veins on its way back to the heart.

Drainage from the brain to the heart is by way of the internal jugular veins.

What's wrong with this statement? Capillaries are the only blood vessels that exchange fluid and blood cells with the surrounding tissue.

Fluid and blood cells also enter and leave the circulation through postcapillary venules.

Why would a ruptured aneurysm of the basilar artery be more serious than a ruptured aneurysm of the anterior communicating artery?

Hemorrhage of the anterior communicating artery would still allow blood to flow into the anterior cerebral arteries by alternative routes. Hemorrhage of the basilar artery, however, would cut off blood supply to the cerebellar arteries and much of the supply to all six cerebral arteries (posterior, middle, and anterior). It is a major trunk supplying all divisions of the cerebral circulation, while the anterior communicating artery is only an anastomosis connecting the two anterior cerebral arteries.

What differences would you expect between a sample of blood taken from the superior mesenteric vein and a sample taken from a hepatic vein? Consider, especially, differences in nutrient levels and bacterial count, and look forward in the book if necessary for a preview of liver functions (section 24.6a).

The difference in blood composition between these two points is that blood in the superior mesenteric vein is on its way to the liver, while blood in the hepatic veins is leaving the liver. Thus the two would differ with respect to the way the liver modifies the blood flowing through it. We could expect fewer nutrients in the blood of the hepatic veins because the liver removes glucose and amino acids, among other nutrients, from the intestinal blood. The liver also removes nearly all bacteria from the intestinal blood. On the other hand, blood leaving the liver contains several proteins that the liver synthesizes and secretes into the blood stream, including albumin, fibrinogen, and all the globulins except antibodies.

Correctly label the following major systemic veins. Deep femoral vein Femoral vein Popliteal vein Anterior tibial veins Small saphenous vein Great saphenous vein Dorsal venous arch

The dorsal venous arch is often visible through the skin on the dorsum of the foot. It gives rise to the small (short) saphenous vein that passes up that side of the leg as far as the knee, where it drains into the popliteal vein and the great (long) saphenous vein, which travels all the way up the leg and thigh into the femoral vein. The deep plantar venous arch receives blood from the toes and gives rise to lateral and medial plantar veins on the respective sides. The lateral plantar vein gives off the fibular veins, then crosses over to the medial side and approaches the medial plantar vein. The two plantar veins pass behind the medial malleolus of the ankle and continue as a pair of posterior tibial veins. The two posterior tibial veins pass up the leg and converge into a single vein about two-thirds of the way up the tibia. The two fibular (peroneal) veins ascend the back of the leg and similarly converge. The popliteal vein begins near the knee by convergence of these two inverted Ys. The two anterior tibial veins travel up the anterior compartment of the leg between the tibia and fibula. They converge just distal to the knee, and then flow into the popliteal vein. The femoral vein is a continuation of the popliteal vein into the thigh. The deep femoral vein drains the femur and muscles of the thigh and drains into the upper femoral vein. The external iliac vein is formed by the union of the femoral and great saphenous veins. The internal iliac vein follows the course of the internal iliac artery and its distribution. The common iliac vein is formed by the union of the external and internal iliac veins. The right and left common iliacs then unite to form the inferior vena cava.

Correctly label the following arteries of the lower limb. Internal iliac artery External iliac artery Femoral artery Deep femoral artery Popliteal artery Posterior tibial artery Fibular artery

The external iliac artery sends small branches to the skin and muscles of the abdominal wall and pelvis, then passes behind the inguinal ligament and becomes the femoral artery. The femoral artery passes through the femoral triangle of the upper medial thigh and gives off several small arteries to the skin and then produces the following branches before descending the rest of the way to the knee. The deep femoral artery arises from the lateral side of the femoral, within the triangle. Two circumflex femoral arteries arise from the deep femoral, encircle the head of the femur, and anastomose laterally. The popliteal artery is a continuation of the femoral artery in the popliteal fossa at the rear of the knee. As it passes through the popliteal fossa, it gives off anastomoses called genicular arteries that supply the knee joint. The anterior tibial artery arises from the popliteal artery and immediately penetrates through the interosseous membrane of the leg to the anterior compartment. Upon reaching the ankle, it gives rise to the following dorsal arteries of the foot. The dorsal artery traverses the ankle and upper medial surface of the foot and gives rise to the arcuate artery. The arcuate artery sweeps across the foot from medial to lateral and gives rise to vessels that supply the toes. The posterior tibial artery is a continuation of the popliteal artery that passes down the leg, deep in the posterior compartment, supplying flexor muscles along the way. Inferiorly, it passes behind the medial malleolus of the ankle and into the plantar region of the foot and gives rise to the medial and lateral plantar arteries, the deep plantar arch, and the fibular (peroneal) artery.

What's wrong with this statement? Most of the muscle in a blood vessel is found in the tunica interna.

The muscle is in the tunica media.

A circulatory pathway in which the blood flows through two capillary beds in series before it returns to the heart is called a/an __________. a) venous anastomosis b) arteriovenous anastomosis c) venous return pathway d) portal system e) arterial anastomosis

d) portal system A portal system is a route in which blood flows through two capillary beds—one after the other—before returning to the heart. For example, in the hepatic portal system, the blood picks up nutrients from a capillary bed in the small intestine, then flows through a series of veins to the liver, where there is a second capillary bed. The blood unloads some nutrients here, picks up substances produced by the liver cells, and then flows to the heart. Other portal systems occur in the kidneys and connecting the hypothalamus to the anterior pituitary gland.

Most blood flowing in all of the following arteries except the _______ is destined to circulate through the brain before returning to the heart. a) vertebral arteries b) internal carotid arteries c) basilar artery d) superficial temporal artery e) anterior communicating artery

d) superficial temporal artery

A circulatory pathway in which the blood flows through two capillary beds in series before it returns to the heart is called a) an arteriovenous anastomosis. b) an arterial anastomosis. c) a venous anastomosis. d) a venous return pathway. e) a portal system.

e) a portal system.

From the preceding discussion of arteries and veins of the limbs, identify an artery or vein with special relevance to each of the following clinical applications: (1) the artery from which blood pressure is usually measured; (2) the artery where a patient's pulse is most often taken; (3) a vessel where pressure should be applied to stop arterial bleeding from a laceration of the thigh; (4) upper and lower limb veins where intravenous fluid is often administered; (5) a vein where blood samples are commonly drawn; and (6) a vein from which a portion may be removed and used for a coronary bypass graft.

—(1) the brachial artery; (2) the radial artery; (3) the femoral artery; (4) cephalic vein and great saphenous vein; (5) median cubital vein; (6) great saphenous vein.