Deck 10: The Blood Vessels and Blood Pressure

Question 1

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

Answer 1

D

Question 2

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 40 large ones in the body.
D) They serve as a blood reservoir.
E) They transport blood away from the heart.

Answer 2

D

Question 3

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

Answer 3

A

Question 4

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

Question 5

At rest, which of the following receives the most blood flow?

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

Question 6

Which type of blood vessel consists of only one cell layer?

A) arteriole
B) artery
C) capillary
D) vein
E) venule

Question 7

The arteries

A) serve as rapid-transit passageways from the heart to the organs 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 sites of blood flow resistance in the vasculature
D) are the site of exchange between the blood and surrounding tissues
E) none of these

Question 8

Which is not true about blood pressure?

A) It is 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 9

The major determinant influencing resistance to blood flow is the

A) viscosity of the blood
B) radius of the vessel through which the blood is flowing
C) pressure gradient in the vessel
D) concentration of red blood cells in the blood
E) amount of plasma protein

Question 10

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

Question 11

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

A) Blood flow decreases by half.
B) Resistance increases 16 times.
C) Blood viscosity increases.
D) All of these.
E) Resistance increases 16 times and blood viscosity increases.

Question 12

The larger arteries assist with systemic blood flow to tissues by

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

Question 13

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) regulate flow of blood through capillary beds and distribute the cardiac output to tissues

Question 14

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 16-fold when the radius of the vessel is reduced by one-half
D) is a measure of the hindrance to blood flow through a vessel caused by friction between the moving fluid and stationary vascular walls, and is doubled when the radius of the vessel is reduced by one-half
E) is a measure of the hindrance to blood flow through a vessel caused by friction between the moving fluid and stationary vascular walls, and increases 16-fold when the radius of the vessel is reduced by one-half

Question 15

Resistance increases when

A) radius decreases
B) length decreases
C) viscosity decreases
D) red blood cell count decreases
E) none of these

Question 16

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

Question 17

Vasoconstriction

A) refers to a decrease in the radius of a vessel
B) of an arteriole decreases blood flow through that vessel
C) of a vein increases blood flow through that vessel
D) refers to a decrease in the radius of a vessel, and vasoconstriction of an arteriole decreases blood flow through that vessel.
E) all of these

Question 18

Because of their elasticity, arteries 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 19

The pulse pressure is the

A) difference between the systolic and diastolic pressures
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 20

Vasoconstriction

A) causes a decrease in resistance
B) refers to a decrease in the radius of a vessel
C) is due to a decrease in sympathetic activity
D) refers to a decrease in the radius of a vessel and is due to a decrease in sympathetic activity
E) all of these

Question 21

Which factor would reduce total peripheral resistance?

A) adrenal medulla hormones
B) angiotensin II
C) red blood cell concentration
D) anaphylactic shock
E) cardiovascular center activity

Question 22

Which local chemical changes do not occur during a period of increased cell activity?

A) increased CO₂
B) increased acid
C) decreased adenosine release
D) increased K⁺
E) increased osmolarity

Question 23

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 24

Increased respiration within a tissue leads to vasodilation of arterioles because

A) Carbon dioxide levels increase.
B) Oxygen levels decrease.
C) Less acid is generated.
D) All of these.
E) Carbon dioxide levels increase and oxygen levels decrease.

Question 25

Which local chemical factor is not associated with vasodilation of arterioles?

A) decreased prostaglandins in the tissue fluid
B) increased CO₂
C) increased acid
D) decreased O₂
E) histamine release

Question 26

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

A) Their radii remain constant.
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 27

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 28

If the arterial blood pressure is recorded at 132/84, what is the mean arterial pressure?

A) 100 mm Hg
B) 93 mm Hg
C) 108 mm Hg
D) 48 mm Hg
E) none of these

Question 29

Which statement about nitric oxide is wrong?

A) It increases the total peripheral resistance by its action on arteriolar smooth muscle.
B) It relaxes digestive tract smooth muscle.
C) It is the direct mediator of penile erection.
D) It is released as "chemical warfare" by macrophages of the immune system.
E) It serves as a novel type of neurotransmitter in the brain.

Question 30

Most sympathetic fibers release ____ at arterioles.

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

Question 31

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 32

During strenuous exercise, blood flow increases to

A) the heart because of local control factors
B) the brain because of reflex control factors
C) the skeletal muscles because of local control factors
D) the heart because of local control factors and the skeletal muscles because of local control factors
E) all of these

Question 33

The myogenic response refers to vascular smooth muscle's tendency to

A) constrict when blood flow increases
B) relax when blood flow increases
C) constrict when stretched
D) dilate when stretched
E) relax when blood flow increases and dilate when stretched

Question 34

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

A) contraction of the ventricles
B) elastic recoil of the stretched arteries
C) sympathetic-induced vasoconstriction
D) skeletal muscles squeezing the blood
E) respiratory movements creating a pressure gradient that drives blood forward

Question 35

Which does not cause arteriolar vasodilation?

A) decreased sympathetic stimulation
B) local decrease in O₂
C) histamine
D) application of heat
E) myogenic response

Question 36

What is the most important factor that increases blood flow through a specific tissue to meet the tissues needs?

A) Vasoconstriction of arteries forces more blood to flow into the tissue served by those arteries.
B) Parasympathetic-induced vasodilation of capillaries within the tissue allows more blood to flow into the tissue.
C) Cellular products cause local vasodilation.
D) Widespread venous vasoconstriction allows blood to dam up at the tissue level.
E) All of these, except vasoconstriction of arteries forces more blood to flow into the tissue served by those arteries.

Question 37

During exercise, there is not an increased blood flow to the

A) skeletal muscles
B) heart
C) skin
D) brain
E) skin and brain

Question 38

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

A) arterioles
B) capillaries
C) metarterioles
D) arteries
E) veins

Question 39

As metabolic activity of an organ or tissue increases, blood flow to that organ increases. This phenomenon is known as

A) pressure autoregulation
B) tissue anoxia
C) active hyperemia
D) hypertension
E) atherosclerosis

Question 40

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

Question 41

Given the following parameters, what would the reabsorption pressure be? - $\quad$ blood pressure at arteriolar end of capilary: $35 \mathrm{~mm}$ Hg
- $\quad$ blood pressure at venule end of capillary: $15 \mathrm{~mm} \mathrm{Hg}$
- $\quad$ blood osmotic pressure: $22 \mathrm{~mm} \mathrm{Hg}$
- $\quad$ interstitial fluid hyclrostatic pressure: $1 \mathrm{~mm} \mathrm{Hg}$
- $\quad$ interstitial fluid osmotic pressure: $0 \mathrm{~mm} \mathrm{Hg}$

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

Question 42

The velocity of blood flow in capillaries is

A) greater than that for arterioles
B) greater than that for veins
C) slow enough to favor adequate exchange of nutrients and wastes
D) greater than that for arterioles and the veins
E) greater than that for veins and slow enough to favor adequate exchange of nutrients and wastes

Question 43

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 44

Reabsorption in capillaries occurs when

A) blood osmotic pressure plus blood hydrostatic pressure exceed outward-driving forces.
B) blood osmotic pressure plus interstitial fluid osmotic pressure exceed outward-driving forces.
C) blood hydrostatic pressure plus blood osmotic pressure is less than inward-driving forces.
D) blood osmotic pressure plus blood hydrostatic pressure exceed outward-driving forces and blood hydrostatic pressure plus blood osmotic pressure is less than inward-driving forces.
E) None of these

Question 45

The process of ultrafiltration

A) is movement of protein-free plasma from the capillaries into the interstitial fluid
B) occurs when capillary blood pressure plus interstitial fluid osmotic pressure exceed blood-osmotic pressure plus interstitial fluid hydrostatic pressure
C) occurs when capillary blood pressure plus plasma osmotic pressure exceed interstitial fluid hydrostatic pressure plus interstitial fluid osmotic pressure
D) is movement of protein-free plasma from the capillaries into the interstitial fluid and occurs when capillary blood pressure plus interstitial fluid osmotic pressure exceed blood-osmotic pressure plus interstitial fluid hydrostatic pressure
E) is movement of protein-free plasma from the capillaries into the interstitial fluid and occurs when capillary blood pressure plus plasma osmotic pressure exceed interstitial fluid hydrostatic pressure plus interstitial fluid osmotic pressure

Question 46

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 47

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 and bringing these dissolved nutrients into contact with the tissue cells
D) processes of ultrafiltration and reabsorption
E) bulk flow

Question 48

The largest total cross-sectional area is found in the

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

Question 49

In most tissues, glucose, a water-soluble substance, crosses capillary walls through

A) water-filled pores
B) endothelial cells
C) sinusoids
D) water-filled pores and endothelial cells
E) water-filled pores and sinusoids

Question 50

Active hyperemia

A) refers to the arteriolar dilation 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 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

Question 51

Edema could result from

A) blockage of lymph vessels, increased capillary blood pressure, and decreased blood osmotic pressure
B) blockage of lymph vessels and increased capillary blood pressure
C) increased capillary blood pressure and decreased blood osmotic pressure
D) blockage of lymph vessels and decreased blood osmotic pressure
E) none of these

Question 52

The movements of fluid across the capillary wall is influenced by

A) capillary blood pressure
B) interstitial fluid hydrostatic pressure
C) plasma osmotic pressure
D) interstitial fluid osmotic pressure
E) all of these

Question 53

The principle force that causes movement of fluid from the tissues into the capillaries is the

A) hydrostatic pressure of the venous blood
B) hydrostatic pressure of the arterial blood
C) osmotic pressure created by the plasma proteins
D) pressure of the lymph
E) none of these

Question 54

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

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

Question 55

Which change will increase fluid reabsorption by the capillaries?

A) decreased interstitial fluid hydrostatic pressure
B) increased capillary blood pressure
C) increased blood osmotic pressure
D) increased interstitial fluid osmotic pressure
E) none of these

Question 56

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 57

What is the primary reason that edema may occur with serious burns?

A) increased venous pressure due to interference with circulation through scarring in the burned area
B) lowering of blood osmotic pressure due to the loss of protein-rich fluid from the surface of the burn
C) blockage of lymphatic drainage from the burned area
D) loss of protein in the urine
E) increased tissue pressure

Question 58

Binding of epinephrine to alpha receptors causes smooth muscle

A) relaxation in arteries
B) relaxation in skeletal muscle arteries
C) constriction in skeletal muscle arteries
D) relaxation in coronary arteries
E) none of these

Question 59

Which of the following alterations could lead to edema?

A) a fall in capillary blood pressure
B) a fall in the concentration of plasma proteins
C) blocked lymph vessels
D) a fall in capillary blood pressure and concentration of plasma proteins
E) a fall in the concentration of plasma proteins and blocked lymph vessels

Question 60

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? - $\quad$ cagill wy blood premane = 32 man Hg
- $\quad$ blood armotic prense $= 23 \mathrm { mm } \mathrm { Hg }$
- $\quad$ intarstitial fluid hydrastedic pratre = $1 \mathrm {~mm}$ Hg
- $\quad$ intarstitial fluid osmotic grange $=$ 0 $\mathrm { mm } \mathrm { Hg }$

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 61

Which of the following conditions might be associated with edema?

A) extensive burns
B) congestive heart failure
C) blocked lymphatics
D) increased venous pressure
E) all of these

Question 62

Regulation of arterial pressure is mediated by reflex mechanisms. One important pressure receptor, a(n) ____, is located in the ____.

A) chemoreceptor; carotid sinus
B) exteroceptor; carotid sinus
C) baroreceptor; carotid sinus
D) chemoreceptor; skeletal muscles
E) baroreceptor; skeletal muscles

Question 63

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

A) constricts arterioles, which increases peripheral resistance
B) decreases end diastolic volume, which increases cardiac output
C) increases stroke volume, which increases cardiac output
D) constricts veins, which increases venous return
E) constricts veins, which increases stroke volume

Question 64

Short-term adjustments in blood pressure are mediated by

A) baroreceptor reflexes
B) changes in cardiac output
C) renal activity
D) baroreceptor reflexes and changes in cardiac output
E) changes in cardiac output and renal activity

Question 65

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 66

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) actively contract to force blood uphill against gravity and passively close to prevent the backflow of blood in the veins
E) all of these

Question 67

Sympathetic stimulation of veins ____ venous pressure and drives ____ blood into the heart.

A) increases; more
B) increases; less
C) decreases; more
D) decreases; less
E) none of these

Question 68

The cardiovascular center responds to rising H⁺/CO₂ by

A) dilating arteries
B) constricting arterioles
C) increasing respiratory rate
D) slowing the heart rate
E) decreasing venous return

Question 69

Which factor promotes an increase in blood pressure?

A) epinephrine
B) aldosterone
C) angiotensin II
D) water retention
E) all of these

Question 70

Mean arterial blood pressure

A) equals stroke volume times heart rate
B) is 91 mm Hg when the blood pressure is recorded as 117/78
C) is 97.5 mm Hg when the blood pressure is recorded as 117/78
D) equals stroke volume times heart rate and is 91 mm Hg when the blood pressure is recorded as 117/78
E) equals stroke volume times heart rate and is 97.5 mm Hg when the blood pressure is recorded as 117/78

Question 71

When blood pressure becomes elevated above normal,

A) The carotid and aortic baroreceptors increase their rate of firing.
B) Sympathetic stimulation of blood vessels increases.
C) Arteriolar vasoconstriction occurs as a compensatory response.
D) Parasympathetic stimulation of the heart increases.
E) All of these.

Question 72

Which of the following factors aids venous return to the heart?

A) sympathetic stimulation of capillaries
B) skeletal muscle pump squeezing blood through veins
C) respiratory pump providing a pressure gradient between the lower and chest veins
D) sympathetic stimulation of capillaries and skeletal muscle pump squeezing blood through veins
E) skeletal muscle pump squeezing blood through veins and respiratory pump providing a pressure gradient between the lower and chest veins

Question 73

The two determinants of mean arterial pressure are ____ and ____.

A) stroke volume; compliance of vessel walls
B) heart rate; stroke volume
C) heart rate; end-diastolic volume
D) cardiac output; total peripheral resistance
E) none of these

Question 74

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 75

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

A) lymph vessels
B) arterioles
C) capillaries
D) veins
E) lymph vessels and veins

Question 76

The veins

A) act as high-resistance passageways for blood flow from the tissues to the heart
B) can serve as a blood reservoir by adjusting their total capacity to accommodate variations in blood volume
C) contain two-way valves that allow blood flow into the heart
D) all of these
E) can serve as a blood reservoir by adjusting their total capacity to accommodate variations in blood volume and contain two-way valves that allow blood flow into the heart

Question 77

Heart and venous valves serve a similar function. They prevent a ____ flow of blood.

A) forward
B) backward
C) turbulent
D) pulsatile
E) laminar

Question 78

Receptors that detect changes in the blood pressure are located in the

A) carotid sinus
B) spinal cord
C) hypothalamus
D) aorta
E) carotid sinus and spinal cord

Question 79

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

Question 80

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

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