Deck 10: The Blood Vessels and Blood Pressure

Question 1

The microcirculation is composed of:

A) arteries, arterioles, and capillaries.
B) arterioles, capillaries, and venules.
C) arteries, capillaries, and venules.
D) arteries, arterioles, and venules.
E) none of these answers.

Answer 1

arterioles, capillaries, and venules.

Question 2

Which is true of blood pressure:

A) its maximal during ventricular diastole
B) it decreases the farther away from the heart.
C) it increases with decreasing resistance.
D) it decreases with decreasing vessel diameter.
E) it can be increased by direct parasympathetic activity.

Answer 2

it decreases the farther away from the heart.

Question 3

The major function of the arterioles is to

A) regulate flow of blood through capillary beds.
B) distribute the cardiac output to tissues.
C) serve as a pressure reservoir.
D) convert the intermittent flow from the heart to a steady outflow.
E) both (a) and (b) above.

Answer 3

both (a) and (b) above.

Question 4

Which is not true of blood pressure:

A) its maximal during ventricular systole.
B) it decreases the farther away from the heart.
C) it increases with increasing resistance.
D) it decreases with increasing vessel diameter.
E) it can be increased by direct parasympathetic activity.

Question 5

Blood flow is affected by

A) pressure differences.
B) the viscosity of the blood.
C) the amount of friction in the blood vessels.
D) the length and diameter of the blood vessels.
E) all of these answers.

Question 6

In an arteriole, if the blood vessel radius is 2 units and then vasoconstricted to 1 units, the resistance:

A) the resistance decreases 16 times.
B) the resistance increases 16 times.
C) flow will be decreased.
D) both (a) and (b) above.
E) both (b) and (c) above.

Question 7

Resistance

A) is a measure of the hindrance to blood flow through a vessel caused by friction between the moving fluid and stationary vascular walls.
B) is doubled when the radius of the vessel is reduced by one-half.
C) increases sixteen-fold when the radius of the vessel is reduced by one-half.
D) both (a) and (b) above.
E) both (a) and (c) above.

Question 8

Resistance increases when

A) radius decreases.
B) length decreases.
C) viscosity decreases.
D) hematocrit decreases.
E) none of these answers.

Question 9

A constant blood supply to this organ is a priority of the circulatory system:

A) heart.
B) kidney.
C) brain.
D) muscle.
E) liver.

Question 10

Which of the following factors would produce the greatest change in blood flow?

A) doubling the radius of the vessel.
B) doubling the difference in the pressure gradient within the vessel.
C) doubling the viscosity of the blood.
D) doubling the length of the vessel.
E) halving the viscosity of the blood.

Question 11

Organs that recondition the blood

A) receive disproportionately large percentages of the cardiac output.
B) can withstand temporary reductions in blood flow much better than can organs that do not recondition the blood.
C) must receive a constant blood supply in order to maintain homeostasis.
D) both (a) and (b) above.
E) both (a) and (c) above.

Question 12

Vasoconstriction

A) causes a decrease in resistance.
B) occurs when there is a decrease in the radius of a vessel.
C) due to a decrease in sympathetic activity.
D) two of these answers.
E) all of these answers.

Question 13

Of the following, which is most important in affecting vessel resistance?

A) length of a blood vessel.
B) diameter of a blood vessel.
C) nature of the blood flow.
D) viscosity of the blood.
E) all of these answers.

Question 14

The larger arteries assist with systemic blood flow to tissues by:

A) contracting their tunica intima.
B) beating their semilunar-type valves.
C) by associating with large veins.
D) elastic recoil of their walls.
E) continuous vasoconstriction.

Question 15

Vasoconstriction

A) refers to a decrease in the radius of a vessel.
B) of an arteriole decreases blood flow through that vessel.
C) of an arteriole is controlled by the parasympathetic system
D) both (a) and (b) above.
E) all of these answers.

Question 16

Which type of blood vessel sometimes contains valves?

A) arteriole.
B) artery.
C) capillary.
D) vein.
E) none of the above

Question 17

Vascular resistance is most influence by:

A) length of a blood vessel.
B) diameter of a blood vessel.
C) nature of the blood flow.
D) viscosity of the blood.
E) all of these equally

Question 18

Which of the following is the correct relationship between pressure, flow, and resistance?

A)
B) flow * pressure gradient = resistance
C)
D)
E)

Question 19

Because the arteries have large radii, they serve as excellent rapid-transit passageways for blood. Their second function, related to their elasticity, is to act as a(n) ____ for maintaining blood flow during diastole.

A) cardiac reserve
B) venous reserve
C) arterial capacitance
D) lymphatic reserve
E) pressure reservoir

Question 20

The arteries

A) serve as rapid-transit passageways from the tissues to the heart because of their large radii.
B) act as a blood reservoir because they have the capacity to store large volumes of blood with little change in their internal pressure.
C) are the major resistive vessels of the vasculature.
D) are the site of exchange between the blood and surrounding tissues.
E) none of these answers.

Question 21

Which of the following properties pertains to the aorta?

A) radius cannot be changed.
B) wall contain a thick layer of smooth muscle.
C) responsible for the distribution of blood flow to the various organs.
D) the major vessel that contribute to total peripheral resistance.
E) richly innervated by sympathetic nerve fibers.

Question 22

Typical mean arterial pressure is?

A) 120 mm Hg
B) 93 mm Hg
C) 10 mm Hg
D) 48 mm Hg
E) none of these answers.

Question 23

If the pulse pressure is 44 mm Hg and the diastolic pressure is 68 mm Hg, the systolic pressure is ____ mm Hg.

A) 22
B) 24
C) 66
D) 112
E) 145

Question 24

Which of the following factors is most important in matching the blood flow through a specific tissue with the metabolic needs of that tissue?

A) sympathetically induced vasoconstriction of the arteries supplying a tissue forces more blood to flow into the tissue.
B) parasympathetically induced vasodilation of the capillaries within a tissue allows more blood to flow into the tissue.
C) local changes within a tissue resulting from increased metabolic activity can produce local arteriolar vasodilation to allow more blood to flow into the tissue.
D) widespread venous vasoconstriction allows blood to dam up at the tissue level.
E) the amount of blood flowing through each tissue remains constant through reflex controls to ensure that metabolic needs are continuously met.

Question 25

The major site of sympathetic blood flow control (resistance changes) is at the

A) arterioles.
B) capillaries.
C) metarterioles.
D) arteries.
E) none of these answers.

Question 26

Extrinsic control of arteriolar radius

A) is accomplished primarily by the sympathetic nervous system.
B) is important in the regulation of arterial blood pressure.
C) can be overridden by local adjustments.
D) is accomplished primarily by the sympathetic nervous system and is important in the regulation of arterial blood pressure.
E) all of these answers.

Question 27

Select the correct statement about veins.

A) their walls are highly muscular.
B) their walls consist of one layer of cells.
C) there are only about forty large ones in the body.
D) those that work against gravity have valves to help promote blood flow
E) they transport blood away from the heart.

Question 28

The following local chemical changes occur during a period of increased cell activity except

A) increased CO₂.
B) increased acid.
C) increased O₂.
D) increased K⁺.
E) increased osmolarity.

Question 29

Each of the following local factors produces the relaxation of arteriolar smooth muscle except increased

A) acid.
B) carbon dioxide.
C) osmolarity.
D) oxygen.
E) potassium.

Question 30

All of the following local chemical factors will cause vasodilation of arterioles, except

A) decreased K⁺.
B) increased CO₂.
C) increased acid.
D) decreased O₂.
E) histamine release.

Question 31

The pulse pressure is the

A) difference between the systolic and diastolic pressure.
B) average pressure throughout the cardiac cycle.
C) maximum pressure exerted in the arteries.
D) minimum pressure exerted in the arteries.
E) change in pressure that can be felt in an artery due to shutting of the aortic valve.

Question 32

The pressure measured in the arteries just before the next ventricular ejection of blood is

A) systolic pressure.
B) diastolic pressure.
C) pulse pressure.
D) mean pressure.
E) none of these answers.

Question 33

The major resistance vessels of the body are the

A) arteries.
B) arterioles.
C) capillaries.
D) lymphatics.
E) veins.

Question 34

Which of the following provides vascular tone?

A) acetylcholine.
B) dopamine.
C) GABA.
D) glycine.
E) norepinephrine.

Question 35

These vessels allow blood to bypass capillary beds:

A) arterioles.
B) capillaries.
C) metarterioles.
D) arteries.
E) none of these answers.

Question 36

What force continues to drive blood through the vasculature during ventricular diastole?

A) ventricular contraction forces blood into the vasculature during ventricular diastole.
B) the elastic recoil of the stretched arterial walls provides the force to continue blood flow in the remaining vascular system during ventricular diastole.
C) sympathetic stimulation produces arterial vasoconstriction, which drives the blood forward into the arterioles during ventricular diastole.
D) skeletal muscle contraction squeezes the blood forward from the arteries during ventricular diastole.
E) respiratory movements produce pressure changes in the chest, which establishes a pressure gradient that drives blood forward from the arteries into the microcirculation.

Question 37

Which of the following properties does not pertain to the arterioles?

A) their radii cannot be changed.
B) their walls contain a thick layer of smooth muscle.
C) they are responsible for the distribution of blood flow to the various organs.
D) they are the major vessels that contribute to total peripheral resistance.
E) they are richly innervated by sympathetic nerve fibers.

Question 38

The pressure that is the difference between ventricular contraction and relaxation is:

A) systolic pressure.
B) diastolic pressure.
C) pulse pressure.
D) mean pressure.
E) none of these answers.

Question 39

Mean arterial pressure is

A) diastolic pressure + (systolic/3).
B) systolic pressure + (pulse pressure/3).
C) diastolic pressure + (pulse pressure/3).
D) pulse pressure - (diastolic pressure/3).
E) pulse pressure + (systolic pressure/3).

Question 40

Increased respiration within a tissue leads to vasodilation of arterioles because

A) carbon dioxide levels increase.
B) oxygen levels decrease.
C) parasympathetic activity increases.
D) parasympathetic activity decreases.
E) both (a) and (b) above.

Question 41

Arterioles to this organ do not normally show vasoconstriction:

A) skeletal muscles.
B) heart.
C) skin.
D) brain.
E) kidney

Question 42

Which does not cause arteriolar vasodilation?

A) decreased sympathetic stimulation.
B) local decrease in O₂.
C) histamine release.
D) application of heat.
E) myogenic response to passive stretch of the vessel

Question 43

Active hyperemia

A) refers to the arteriolar dilation that occurs within a tissue in response to local chemical changes that accompany increased metabolic activity of the tissue.
B) refers to local arteriolar mechanisms that are aimed at keeping tissue blood flow fairly constant in spite of rather wide deviations in mean arterial driving pressure.
C) refers to the increase in blood flow to a tissue that occurs after removal of an occlusion of its blood supply.
D) is important in maintaining an adequate pressure head to drive blood forward into a tissue.
E) none of these answers.

Question 44

Which factor pulls fluid back into the blood?

A) capillary blood pressure.
B) interstitial-fluid hydrostatic pressure.
C) plasma protein concentration.
D) interstitial-fluid protein concentration.
E) concentration of glucose in the capillary.

Question 45

Through which vessel is the velocity of blood flow the slowest?

A) aorta
B) arterioles
C) capillaries
D) venules
E) veins

Question 46

What is the primary method by which materials such as O₂, CO₂ and nutrients are exchanged between the blood and surrounding tissues?

A) passive diffusion of substances across the capillary wall down their concentration gradients.
B) active transport of materials across the capillary wall.
C) osmotic pressure drawing water and solutes out of the capillary, bringing these dissolved nutrients into contact with the tissue cells.
D) processes of ultrafiltration and reabsorption.
E) bulk flow.

Question 47

The largest total cross-sectional area is found in the

A) aorta.
B) arterioles.
C) capillaries.
D) venules.
E) veins.

Question 48

Which of the following is not a characteristic of capillaries?

A) thin walls.
B) short distance between adjacent vessels.
C) distensible walls.
D) slow blood velocity.
E) large total surface area.

Question 49

The cells in capillaries in this organ exhibit fenestrations that promote exchange:

A) heart
B) kidney
C) liver
D) skin
E) brain

Question 50

Reabsorption occurs

A) inward-driving pressures exceed the outward-driving pressures across the capillary wall.
B) outward-driving pressures exceed the inward-driving pressures across the capillary wall.
C) due increased osmolarity of plasma in the venule end of the capillary.
D) both (a) and (c) above.
E) both (b) and (c) above.

Question 51

Which factor would reduce total peripheral resistance?

A) adrenal medulla hormones.
B) angiotensin II.
C) increased hematocrit.
D) anaphylaxis.
E) cardiovascular center activity.

Question 52

The four factors that influence bulk flow include all of the following except:

A) capillary blood pressure
B) plasma colloid osmotic pressure
C) interstitial fluids hydrostatic pressure
D) intracellular hydrostatic pressure
E) interstitial fluid-colloid osmotic pressure

Question 53

The movements of fluid across the capillary wall depend on all of the following except

A) capillary blood pressure.
B) interstitial-fluid hydrostatic pressure.
C) plasma protein concentration.
D) interstitial-fluid protein concentration.
E) concentration of glucose in the capillary.

Question 54

Local chemical/metabolic influences on arteriolar radius include all of the following except:

A) local metabolic chemicals
B) histamine
C) myogenic stretch
D) application of cold or heat
E) NE

Question 55

The velocity of blood flow in capillaries

A) is greater than that for arterioles.
B) is greater than that for veins.
C) is slow enough to favor adequate exchange.
D) both (a) and (b) above.
E) both (a) and (c) above.

Question 56

Fluid movement into and out of the capillary is dependent on ____ and ____ pressures working in ____ direction(s).

A) hydrostatic, osmotic, opposite
B) hydrostatic, osmotic, the same
C) filtration, absorption, the same
D) length, filling, the same
E) protein content, blood pressure, the same

Question 57

Vessels associated with this organ are almost entirely under the control of local mechanisms:

A) heart
B) kidney
C) liver
D) skin
E) brain

Question 58

During exercise, there is not an increased blood flow to which of the following tissues?

A) skeletal muscles.
B) heart.
C) skin.
D) brain.
E) blood flow is increased to all of these tissues during exercise.

Question 59

Which of the following changes could lead to edema?

A) decreasing capillary blood pressure.
B) decreasing interstitial-fluid hydrostatic pressure.
C) increasing plasma protein concentration.
D) increasing interstitial-fluid protein concentration.
E) none of the above

Question 60

As the total cross-sectional area of the vascular tree ____, the velocity of blood flow ____.

A) increases, decreases
B) increases, increases
C) decreases, decreases
D) increases, remains constant
E) decreases, remains constant

Question 61

Each of the following factors promotes the function of the capillaries except

A) a blood pressure forcing fluid out of these vessels.
B) a small total surface area.
C) an osmotic pressure drawing fluid into these vessels.
D) pores in the endothelial wall.
E) thin walls.

Question 62

A sudden increase in pressure within the carotid sinus leads to

A) increased sympathetic nerve activity.
B) increased sympathetic nerve activity and decreased parasympathetic nerve activity.
C) decreased sympathetic nerve activity and increased parasympathetic nerve activity.
D) decreased sympathetic nerve activity.
E) none of these answers.

Question 63

Organs that do not adjust the blood are more vulnerable to reductions in blood flow than are organs that perform homeostatic functions on the blood.

Question 64

Which statement regarding sympathetic stimulation effects on blood pressure is incorrect?

A) vasoconstriction of arterioles increases total peripheral resistance.
B) decreased end diastolic volume increases cardiac output.
C) increased stroke volume increases cardiac output.
D) vasoconstriction of veins increases venous return
E) vasoconstriction of veins increases stroke volume.

Question 65

Given the following parameters: blood capillary pressure at arteriolar end of tissue capillaries: 35 mm Hg; blood capillary pressure at venule end of tissue capillaries: 15 mm Hg blood-colloid osmotic pressure: 22 mm Hg
Interstitial-fluid hydrostatic pressure: 1 mm Hg
Interstitial-fluid-colloid osmotic pressure:
0 mm Hg; what would the reabsorption pressure be?

A) 6 mm Hg
B) 7 mm Hg
C) 8 mm Hg
D) 10 mm Hg
E) 22 mm Hg

Question 66

Given the following forces acting at a given point across the capillary wall, what type of fluid movement will be taking place at that point? Capillary blood pressure = 32 mm Hg Blood-colloid osmotic pressure = 23 mm Hg Interstitial-fluid hydrostatic pressure = 1 mm Hg Interstitial-fluid-colloid osmotic pressure = 0 mm Hg

A) Ultrafiltration will occur with a net outward pressure of 8 mm Hg.
B) Ultrafiltration will occur with a net outward pressure of 10 mm Hg.
C) Ultrafiltration will occur with a net outward pressure of 56 mm Hg.
D) Reabsorption will occur with a net inward pressure of 24 mm Hg.
E) Reabsorption will occur with a net inward pressure of 10 mm Hg.

Question 67

Which of the following does not occur as a compensation for hemorrhage?

A) shift of fluid from the interstitial fluid into the plasma.
B) reduced urinary output.
C) increased capillary permeability.
D) increased cardiac output.
E) increased synthesis of plasma proteins.

Question 68

Which vessels play an important role in preventing edema?

A) arteries.
B) arterioles.
C) capillaries.
D) veins.
E) lymph vessels.

Question 69

The walls of the veins contain smooth muscle innervated by sympathetic nerve fibers. Sympathetic stimulation ____ venous pressure and drives ____ blood into the heart.

A) increases, more.
B) increases, less.
C) decreases, more.
D) decreases, less.
E) none of these answers.

Question 70

Which vessels can act as a blood reservoir by adjusting their total capacity to accommodate variations in blood volume?

A) arteries.
B) arterioles.
C) capillaries.
D) veins.
E) lymph vessels.

Question 71

When the blood pressure becomes elevated above normal,

A) the carotid-sinus and aortic-arch baroreceptors increase their rate of firing.
B) the cardiovascular control center decreases sympathetic and increases parasympathetic activity to the heart and blood vessels.
C) arteriolar vasodilation occurs as a compensatory response.
D) two of these answers.
E) all of these answers.

Question 72

Which vessels contain the highest percentage of total blood volume?

A) pulmonary veins.
B) pulmonary arteries.
C) systemic veins.
D) systemic arteries.
E) coronary arteries.

Question 73

Short term adjustments in blood pressure are mediated by

A) baroreceptor reflexes.
B) sympathetic system
C) renal activity
D) both (a) and (b) above.
E) both (b) and (c) above.

Question 74

If the pressure gradient in a vessel is constant, flow will double when the radius decreases by two-fold.

Question 75

Organs that recondition the blood normally receive considerably more of the cardiac output than is necessary to meet their metabolic needs.

Question 76

Which of the following does not occur to compensate for a fall in blood pressure below normal?

A) cardiac output is increased.
B) total peripheral resistance is decreased.
C) heart rate is increased.
D) venous vasoconstriction occurs.
E) stroke volume is increased.

Question 77

Shock may develop

A) from loss of blood.
B) from low cardiac output.
C) from anaphylaxis.
D) excess vasodilation.
E) all of these answers.

Question 78

Hypertension may be caused by all of these except

A) renal disease.
B) hardening of the arteries.
C) suppression of baroreceptors.
D) salt imbalances.
E) adrenal medullary tumors.

Question 79

The venous valves

A) actively contract to force blood uphill against gravity.
B) passively close to prevent the backflow of blood in the veins.
C) are positioned at the entrances to the atria.
D) both (b) and (c) above.
E) all of these answers.

Question 80

Which of the following is not a function of the lymphatic system?

A) defense against disease.
B) return of fluid to the circulatory system.
C) transport of fat molecules.
D) regulation of sodium balance.
E) return of proteins to the circulatory system.