Blood Vessels

Which is the most common type of capillary? Fenestrated Sinusoids Continuous Venules Discontinuous

Continuous

Which statement accurately compares filtration and reabsorption? Filtration is driven by concentration gradients, whereas reabsorption depends on hydrostatic pressure. Filtration involves bulk flow of fluid out of the blood, whereas reabsorption is bulk flow back into the blood. Filtration happens at the venule end of a capillary bed and reabsorption happens in feeder arterioles. The direction of filtration can be either into or out of the blood, but reabsorption always involves fluids entering the blood.

Filtration involves bulk flow of fluid out of the blood, whereas reabsorption is bulk flow back into the blood.

Which of the artery types contain the internal and external elastic laminae? Elastic arteries Arterioles Muscular arteries Elastic and muscular arteries Elastic arteries and arterioles

Muscular arteries

Which part of the circulatory system holds the largest amount of blood? Pulmonary arteries Pulmonary veins Systemic arteries Systemic veins

Systemic arteries

Systolic pressure is greater than diastolic pressure due to the force generated by ventricular contraction. True False

True

The contraction of skeletal muscles plays an important role in the movement of blood in the veins. True False

True

The higher the degree of vascularization in a tissue, the greater the potential for local blood flow. True False

True

Sinusoids are found in: a: bone marrow b: spleen c: small intestine d: kidney e: liver f: muscle g: skin a, b, e b, c, e, f c, d f, g b, c, d, g

a, b, e

Precapillary sphincters will: control blood flow into the true capillaries. cause blood to flow directly from the metarteriole into the postcapillary venule. open when the tissue needs nutrients. close when the tissue's needs have been met. All of these answers are correct

control blood flow into the true capillaries.

Gas, nutrient, and waste exchange occur between the __________ and the tissues of the body. arteries veins capillaries capillaries and veins capillaries and arteries

capillaries

The cardiac center of the brainstem includes the: cardioacceleratory center from which parasympathetic pathways extend. cardioacceleratory center from which sympathetic pathways extend. vasomotor center from which parasympathetic pathways extend. cardioinhibitory center from which sympathetic pathways extend. All of the choices are correct.

cardioacceleratory center from which sympathetic pathways extend.

Valves in veins: make the use of a skeletal muscle pump unnecessary for venous blood flow. are the leading cause of high blood pressure. are found only in the largest veins. cause venous blood flow to go in only one direction. are formed of the tunica media.

cause venous blood flow to go in only one direction.

High carbon dioxide levels and low pH in blood of the carotid arteries will stimulate: baroreceptors to activate the vasomotor center. chemoreceptors to activate the vasomotor center. baroreceptors to activate the cardioinhibitory center and inhibit the cardioacceleratory center. chemoreceptors to inhibit the vasomotor center. baroreceptors and chemoreceptors to activate the cardioinhibitory center and inhibit the vasomotor center.

chemoreceptors to activate the vasomotor center.

Blood velocity is measured in _________ and is generally _________ related to total cross-sectional area of blood vessels. cm/second, directly cm/second, inversely liter/min, directly liter/min, inversely

cm/second, inversely

Oxygen and carbon dioxiode are transported between the blood and interstitial fluid by way of: exocytosis and endocytosis by endothelial cells. pinocytosis using fluid-filled vesicles. diffusion from areas of higher concentration to lower concentration. active transport (using ATP) by protein carriers of endothelial cells.

diffusion from areas of higher concentration to lower concentration.

The function of the postcapillary venule is to: allow for diffusion of nutrients to the tissues. allow for diffusion of metabolic wastes from the tissues. drain the capillary bed. supply metarteriole with blood. allow for diffusion of nutrients and metabolic wastes

drain the capillary bed.

The largest arteries of the body are classified as: muscular arteries. arterioles. elastic arteries. muscular and elastic since they have the same dimensions. None of these answers is correct.

elastic arteries.

As a venous pathway moves closer to the heart, the veins: get smaller. get larger. show no change in their lumen size.

get larger.

As an arterial pathway moves farther from the heart, the arteries: get smaller. get larger. show no change in their lumen size.

get smaller.

Excitation of the vasomotor center results in: increased sympathetic activity and predominantly more vasoconstriction than vasodilation. increased parasympathetic activity and predominantly more vasodilation than vasoconstriction. increased autonomic activity that increases heart rate and dilates blood vessels. decreased autonomic activity that decreases heart rate and constricts blood vessels. redistribution of blood flow away from the skeletal muscles and toward the skin.

increased sympathetic activity and predominantly more vasoconstriction than vasodilation.

Increased cardiac output ______ the blood pressure. decreases increases will not affect

increases

Aldosterone and atrial natriuretic peptide have ________ effects on blood pressure. similar opposite

opposite

Considering the bulk flow that occurs at capillary beds, the lymphatic system is needed to: reabsorb excess fluid from the interstitial fluid. filter additional fluid to the interstitial fluid. connect arterioles to venules and provide a shunt from the true capillaries. regulate colloid osmotic pressure so that filtration levels do not decline.

reabsorb excess fluid from the interstitial fluid.

The ________ is composed of an endothelium and a subendothelial layer made up of a thin layer of areolar connective tissue. tunica media tunica externa tunica intima tunica adventitia None of the answers is correct

tunica intima

The ________ is composed of circularly arranged layers of smooth muscle cells. tunica media tunica externa tunica intima tunica interna None of the answers is correct.

tunica media

In arteries, the thickest layer of the wall is the: tunica externa. tunica media. tunica intima. tunica adventitia. None of these because all the layers are of the same dimension

tunica media.

A network of small arteries called the ___________ provides a blood supply to the tunica externa of very large vessels. vasa vasorum companion vessels distributing arteries fenestrated arteries thoroughfare channels

vasa vasorum

Angiotensin II causes: increased heart rate, vasodilation, and less urine formation. decreased heart rate, vasoconstriction, and increased urine formation. vasoconstriction, decrease urine formation, and increased thirst. decreased thirst, vasodilation, and increased urine formation. vasoconstriction, increased urine formation, and decreased thirst.

vasoconstriction, decrease urine formation, and increased thirst.

When physical exertion has ended and the body is at rest, veins demonstrate: vasodilation so that they function as blood reservoirs. vasodilation so that blood is shifted toward the rest of the circulatory system. vasoconstriction so that they function as blood reservoirs. vasoconstriction so that blood is shifted toward the rest of the circulatory system.

vasodilation so that they function as blood reservoirs.

Atrial natriuretic peptide stimulates: vasoconstriction, increased urine output, and therefore increased blood pressure. vasodilation, increased urine output, and therefore decreased blood pressure. vasoconstriction, decreased urine output, and therefore decreased blood pressure. vasodilation, decreased urine output, and therefore increased blood pressure. vasoconstriction, sodium retention, and therefore increased blood pressure.

vasodilation, increased urine output, and therefore decreased blood pressure.

Blood pressure is lowest in: arteries. veins. arterioles. venules. capillaries.

veins

Imagine someone who drank too much water before running a race. Their very watery blood would be: high viscosity and therefore have high resistance. high viscosity and therefore have low resistance. low viscosity and therefore have high resistance. low viscosity and therefore have low resistance.

low viscosity and therefore have low resistance.

Concerning the exchange between blood and interstitial fluid at systemic capillaries: more fluid is absorbed and reabsorbed than is filtered. more fluid is filtered than reabsorbed. the fluid reabsorbed into the capillary exactly matches the amount filtered by the capillary.

more fluid is filtered than reabsorbed.

Blood colloid osmotic pressure is largely due to: the proteins in the blood, and it promotes reabsorption. the high amount of water in the blood, and it promotes diffusion out of the capillaries. the proteins in the blood, and it promotes filtration. the pressure generated by the heart, and it favors osmosis into the arteriole end of the capillary bed. the high amount of water in the blood, and it promotes filtration from arterioles.

the proteins in the blood, and it promotes filtration.

To prevent excessive blood loss following tissue damage, local chemicals such as: bradykinins are released to trigger vasoconstriction. nitric oxides are released to trigger vasoconstriction. thromboxanes are released to trigger vasoconstriction. prostaglandins are released to trigger vasodilation. vasopressins are released to trigger vasodilation.

thromboxanes are released to trigger vasoconstriction.

A venule becomes a vein when its diameter is greater than ____ micrometers. 1 10 100 1000

100

If someone's blood pressure were listed as 125/75 mmHg, then their pulse pressure would be: 125 mmHg. 5/3. 50 mmHg. 40 mmHg. 100 mmHg.

50 mmHg.

If someone's blood pressure were listed as 110/65 mmHg, then their mean arterial pressure (MAP) would be: 70 mmHg. 80 mmHg. 90 mmHg. 100 mmHg. 110 mmHg.

80 mmHg.

Imagine a patient who loses lots of blood and therefore has less stretch of their aorta with each heartbeat. What reflex will result? Baroreceptors increase firing, the vasomotor center increases firing, and skin blood vessels will dilate to cause a compensatory increase in flow. Baroreceptors decrease firing, the cardioacceleratory center increases firing, and cardiac output will exhibit a compensatory increase. Baroreceptors increase firing, the cardioinhibitory center increases firing, and the heart slows significantly to prevent further bleeding.

Baroreceptors decrease firing, the cardioacceleratory center increases firing, and cardiac output will exhibit a compensatory increase.

During exercise, blood flow to skeletal muscles increases. What other blood flow changes occur? Blood flow to coronary vessels increases, and flow to abdominal organs decreases. Blood flow to skin decreases, and flow to the kidneys increases. Blood flow to coronary vessels increases, and flow to skin and brain decreases. Blood flow to skin, heart, and kidneys decreases.

Blood flow to coronary vessels increases, and flow to abdominal organs decreases.

Imagine yourself sitting in an awkward position in an uncomfortable chair that is depriving part of your leg from normal blood flow. This deprivation of adequate perfusion will result in what sort of local changes in your leg? Decreases in carbon dioxide and hydrogen ions will cause vasodilation. Build up of carbon dioxide and hydrogen ions will cause vasoconstriction. Build up of carbon dioxide and hydrogen ions will cause vasodilation. Decreases in oxygen and potassium will cause vasoconstriction. Increases in oxygen and potassium will cause vasodilation.

Build up of carbon dioxide and hydrogen ions will cause vasodilation.

A vasodilator causes a decrease in local blood flow at a capillary bed. True False

False

Although local blood flow to different organs varies from time to time (based on demand), the distribution of blood vessels in the various organs of the body is fairly similar. True False

False

Increases in angiotensin II levels cause decreases in blood pressure. True False

False

Of the three artery types, the elastic arteries have the greatest ability to vasoconstrict and vasodilate. True False

False

Which statement accurately describes total blood flow? Total blood flow equals cardiac output and is a fixed number given that there is a finite amount of blood in the body. Total blood flow equals cardiac output and can vary significantly over time with activity levels. Total blood flow is measured as the sum of blood flow to upper and lower extremities and is measured in liters. Total blood flow is measured as the sum of blood flow to upper and lower extremities and is measured in beats per minute. Changes in total blood flow are accompanied by equivalent changes in local blood flow in all areas of the body.

Total blood flow equals cardiac output and can vary significantly over time with activity levels.

Epinephrine, aldosterone, and antidiuretic hormone each cause an increase in blood pressure. True False

True

Some large molecules, such as fatty acids, are transported between capillaries and tissues by vesicular transport. True False

True

Tendons and ligaments have: a high degree of vascularization, therefore high perfusion and rapid healing. a high degree of vascularization, therefore high perfusion and slow healing. a high degree of vascularization, therefore low perfusion and slow healing. a low degree of vascularization, therefore high perfusion and rapid healing. a low degree of vascularization, therefore low perfusion and slow healing.

a low degree of vascularization, therefore low perfusion and slow healing.

If someone suffered from hypertension, such that the blood pressure in their capillaries was elevated, then net filtration pressure would be: above normal. below normal.

above normal.

Angiogenesis: is a momentary chemical control of local blood flow. involves muscular constriction of arterioles to alter local perfusion. allows for an increase in the perfusion of a local tissue. involves building new muscle tissue and decreasing the amount of blood vessels

allows for an increase in the perfusion of a local tissue.

In general, as an artery's diameter decreases, the artery walls show: a decrease in the relative amount of smooth muscle and an increase in the relative amount of elastic fibers. an increase in the relative amount of smooth muscle and a decrease in the relative amount of elastic fibers. an increase in relative amounts of smooth muscle and elastic fibers and a decrease in endothelium. a decrease in both smooth muscle and elastic fibers and an increase in areolar connective tissue.

an increase in relative amounts of smooth muscle and elastic fibers and a decrease in endothelium.

Renin converts: antiotensin I to antiotensin II. angiotensin II to angiotensin I. angiotensinogen to angiotensin I. antidiuretic hormone to angiotensin. antidiuretic hormone to angiotensinogen.

angiotensinogen to angiotensin I.

If someone were to have abnormally low levels of protein in their blood, then net filtration pressure would: be higher than normal. be lower than normal.

be higher than normal.

The respiratory pump assists blood movement within the veins of the trunk, because as a person inspires: intra-abdominal and intrathoracic pressure both increase. intra-abdominal and intrathoracic pressure both decrease. intra-abdominal pressure increases and intrathoracic pressure decreases. intra-abdominal pressure decreases and intrathoracic pressure increases.

intra-abdominal pressure increases and intrathoracic pressure decreases.

The force per unit area that blood places on the inside wall of a blood vessel: is called the pulse. is called the blood pressure. increases the further the vessel is from the heart. is greater during diastole. is greater in the inferior vena cava than in the common iliac vein.

is called the blood pressure.

A portal system: includes a functional end artery that makes an arterial anastomosis. is a simple circulatory system with an areriovenous anastomosis. is one in which blood flows through two capillary beds before being sent back to the heart. is one in which circulation to a large organ involves only one artery and one main (portal) vein. is one in which multiple arteries converge on one organ or body region.

is one in which blood flows through two capillary beds before being sent back to the heart.

If someone were to decrease their food intake and increase aerobic exercise, they might lose adipose tissue and condition their muscles. These changes would also influence their blood vessels, as there would be: regression of blood vessels in adipose and angiogenesis in skeletal muscle. angiogenesis in both adipose tissue and skeletal muscle. regression of blood vessels in both adipose and skeletal muscle. angiogenesis in adipose and regression of blood vessels in skeletal muscle. changes in the diameter of blood vessels, but no angiogenesis nor regression.

regression of blood vessels in adipose and angiogenesis in skeletal muscle.

Circulation to the spleen demonstrates a(n): simple pathway, as one artery delivers blood and one vein drains the organ. simple pathway, as its two capillary beds are separated by a portal vein. anastomosis, as one artery delivers blood and one vein drains the organ. anastomosis, as its two capillary beds are separated by a portal vein.

simple pathway, as one artery delivers blood and one vein drains the organ.

The velocity of blood flow through capillaries is: rapid, due to their small total cross sectional area. rapid, which prevents pooling in lower extremeties. slow, due to small total cross sectional area, low friction and high pressure. slow, which allows sufficient time for exchange of gases and nutrients between

slow, which allows sufficient time for exchange of gases and nutrients between

At a capillary bed, a vasoconstrictor: constricts local arterioles thereby increasing pressure and increasing local blood flow. stimulates precapillary sphincters and decreases local blood flow. dilates local arterioles thereby increasing pressure and increasing local blood flow. inhibits precapillary sphincters to relax and decreases local blood flow. constricts precapillary sphincters and thereby increases local blood flow.

stimulates precapillary sphincters and decreases local blood flow.

Atherosclerosis involves a: sustained increase in blood flow that leads to decreases in venous resistance to keep blood pressure constant. sustained increase in resistance that leads to increases in arterial pressure to maintain adequate blood flow. sustained decrease in resistance that leads to decreases in arterial pressure to maintain adequate blood flow. sustained decrease in blood flow that leads to increases in arterial diameter to lower resistance and raise pressure. sustained increase in blood pressure that leads to compensatory vasodilation

sustained increase in resistance that leads to increases in arterial pressure to maintain adequate blood flow.