Deck 10: The Blood Vessels and Blood Pressure

Question 1

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 venous pressure
E)mean arterial pressure

Answer 1

B

Question 2

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)capillaries only

Answer 2

B

Question 3

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

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

Answer 3

C

Question 4

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

A) $\text { flow } = \frac { \text { pressure gradient } } { \text { radius } ^ { 4 } }$
B) $\text { flow } \times \text { pressure gradient } = \text { resistance }$
C) $\text { flow } = \frac { \text { pressure gradient } } { \text { resistance } }$
D) $\text { pressure gradient } = \frac { \text { flow } } { \text { resistance } }$
E) $\text { pressure gradient } = \frac { \text { flow } } { \text { radius } ^ { 4 } }$

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 the above

Question 6

The larger arteries assist with systemic blood flow to tissues by

A)contracting their endothelial layer
B)using valves to propel the blood
C)providing blood directly to large veins
D)elastic recoil of their walls
E)continuous vasoconstriction

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 16-fold when the radius of the vessel is reduced by one-half
D)is both a and b
E)is both a and c

Question 8

The arteries

A)serve as rapid-transit passageways from 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 sites of blood flow resistance in the vasculature
D)are the site of exchange between the blood and surrounding tissues
E)always carry oxygenated blood

Question 9

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)is both a and b
E)is both b and c

Question 10

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)is defined in "a" and causes "b"
E)is defined in "a" and causes "c"

Question 11

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 12

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.

Question 13

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 14

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)perform functions a and b

Question 15

Which is not true about blood pressure?

A)It is maximal during ventricular systole.
B)It decreases as blood moves 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 16

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)have characteristics a and b
E)have characteristics b and c

Question 17

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 the above will occur
E)only b and c occur

Question 18

Resistance increases when

A)vessel radius decreases
B)vessel length decreases
C)blood viscosity decreases
D)red blood cell count decreases
E)both a and b occurs

Question 19

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 20

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

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

Question 21

Arterioles in which of the following receive stimulation from parasympathetic neurons?

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

Question 22

During exercise, blood flow to the _____ remains fairly constant.

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

Question 23

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 24

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 25

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 26

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)do both b and d

Question 27

Which of the following does not cause relaxation of smooth muscle within local arterioles?

A)carbon dioxide
B)endothelin
C)nitric oxide
D)histamine
E)increased osmolarity

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

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 30

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 31

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

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

Question 32

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 33

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

A)decreased nitric oxide
B)increased CO₂
C)increased acid
D)decreased O₂
E)increased histamine

Question 34

Which statement about nitric oxide is incorrect?

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 35

Extrinsic control of arteriolar radius is

A)accomplished primarily by the sympathetic nervous system
B)important in the regulation of arterial blood pressure
C)sometimes overridden by local adjustments
D)all of the above
E)only a and b

Question 36

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)both a and c
E)none of the above; blood flow remains fairly constant to these organs

Question 37

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 38

Which of the following does not cause arteriolar vasodilation?

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

Question 39

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

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

Question 40

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

A)Their radii remain constant.
B)Their walls contain a relatively 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 41

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 42

Given the following forces acting at a given point across the capillary wall, _______ will occur with a net ______ pressure of ____ mm Hg.
- capillary blood pressure = 32 mm Hg
- blood osmotic pressure = 23 mm Hg
- interstitial fluid hydrostatic pressure = 1 mm Hg
- interstitial fluid osmotic pressure = 0 mm Hg

A)Ultrafiltration, outward, 8
B)Ultrafiltration, outward, 10
C)Ultrafiltration, outward, 56
D)Reabsorption, inward, 24
E)Reabsorption, inward, 10

Question 43

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 both a and b
E)is both a and c

Question 44

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

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

Question 45

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

A)the hydrostatic pressure of the venous blood
B)the hydrostatic pressure of the arterial blood
C)the osmotic pressure created by the plasma proteins
D)the pressure of the lymph in the tissues around the capillaries
E)none of the above

Question 46

Reabsorption in capillaries occurs

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

Question 47

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 48

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 49

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

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

Question 50

Active hyperemia refers to

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

Question 51

Given the following parameters, what would the reabsorption pressure be?
- Blood pressure at arteriolar end of capillary = 35 mm Hg
- Blood pressure at venule end of capillary = 15 mm Hg
- Blood osmotic pressure = 22 mm Hg
- Interstitial fluid hydrostatic pressure = 1 mm Hg
- Interstitial fluid osmotic pressure: 0 mm Hg

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

Question 52

The largest total cross-sectional area is found in the

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

Question 53

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 across the capillary wall down their concentration gradients
B)active transport 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)ultrafiltration and reabsorption
E)bulk flow

Question 54

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 hydrostatic pressure

Question 55

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)Both a and b
E)Both b and c

Question 56

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)both a and b
E)both a and c

Question 57

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 the above

Question 58

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

A)hydrostatic pressure, osmotic pressure, opposite
B)hydrostatic pressure, osmotic pressure, the same
C)ultrafiltration rate, bulk flow rate, the same
D)ultrafiltration rate, bulk flow rate, opposite
E)protein removal rate, hydrostatic pressure, the same

Question 59

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 the above

Question 60

Binding of epinephrine to alpha receptors causes smooth muscle

A)relaxation in arteries of the brain
B)relaxation in skeletal muscle arteries
C)constriction in skeletal muscle arteries
D)relaxation in coronary arteries
E)to not experience any of the above

Question 61

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 the above occur

Question 62

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 choices above correctly complete the sentence.

Question 63

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 one-way valves that prevent backflow as blood moves toward the heart
D)have characteristics a and b
E)have characteristics b and c

Question 64

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)prevent blood from flowing into lymphatic vessels
D)primarily prevent blood plasma from moving into the interstitial fluid
E)perform all of the above functions

Question 65

Which of the following is not associated with sympathetic stimulation?

A)Constriction of arterioles, which increases peripheral resistance
B)Decreased end diastolic volume, which increases cardiac output
C)Increased stroke volume, which increases cardiac output
D)Constriction of veins, which increases venous return
E)Constriction of veins, which increases stroke volume

Question 66

Regulation of arterial pressure can be mediated by a reflex mechanism utilizing a pressure receptor called a ______, located in the ____.

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

Question 67

All the following compensate for a fall in blood pressure below normal except

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

Question 68

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)is both a and b
E)is both a and c

Question 69

Which of the following conditions might be the cause of edema?

A)Extensive burns
B)Congestive heart failure
C)Blocked lymphatics
D)Increased venous pressure
E)All of the above

Question 70

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 71

Edema could result from

A)blockage of lymph vessels
B)increased capillary blood pressure
C)decreased blood osmotic pressure
D)all of the above
E)only a and b

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

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 74

Short-term adjustments in blood pressure are mediated by

A)baroreceptor reflexes
B)changes in cardiac output
C)renal activity
D)both a and b
E)both b and c

Question 75

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 the above

Question 76

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 77

Receptors that detect changes in the blood pressure are located in

A)the carotid sinus
B)the aorta
C)the hypothalamus
D)all of the above
E)both a and b

Question 78

Which of the following would promote an increase in blood pressure?

A)epinephrine
B)aldosterone
C)angiotensin II
D)water retention
E)All of the above

Question 79

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 80

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)Both a and b
E)Both b and c