Deck 9: Vascular Physiology

Question 1

To which of these terms is vascular resistance related

A)venous system
B)diameter of a blood vessel
C)location of a blood vessel
D)component of white blood cell count

Answer 1

B

Question 2

Which statement applies to vascular resistance

A)It is a measure of the hindrance to blood flow through a vessel caused by friction between the moving fluid and stationary vascular walls.
B)It is doubled when the radius of the vessel is wider than normal.
C)It is inversely proportional to blood viscosity.
D)It is increased when blood vessel length is shorter.

Answer 2

A

Question 3

Because the arteries have large radii, they serve as excellent rapid-transit passageways for blood.What is their second function-which is related to their elasticity-in maintaining blood flow during diastole

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

Answer 3

D

Question 4

Which of these terms is the pressure measured in the arteries just before the next ventricular ejection of blood

A)systolic pressure
B)diastolic pressure
C)pulse pressure
D)mean pressure

Question 5

Which of these pairs contains the two determinants of mean arterial pressure

A)stroke volume and compliance of vessel walls
B)heart rate and stroke volume
C)heart rate and end-diastolic volume
D)cardiac output and total peripheral resistance

Question 6

Which of these statements describes pulse pressure

A)It is the difference between systolic and diastolic pressures.
B)It is the average pressure throughout the cardiac cycle.
C)It is the maximum pressure exerted in the arteries.
D)It is the minimum pressure exerted in the arteries.

Question 7

Which of these factors does NOT affect blood pressure positively

A)skeletal muscle activity
B)aldosterone release
C)renin release
D)calcium reabsorption

Question 8

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

A)48 mmHg
B)93 mmHg
C)100 mmHg
D)108 mmHg

Question 9

What is the relationship between pressure, flow, and resistance

A)flow = pressure gradient / radius4
B)flow / pressure gradient = resistance
C)flow = pressure gradient / resistance
D)pressure gradient = flow / radius4

Question 10

In which of these vessels is the largest total cross-sectional area found

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

Question 11

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

A)ventricular contraction
B)elastic recoil of the stretched arterial walls
C)production of arterial vasoconstriction by sympathetic stimulation
D)skeletal muscle contraction

Question 12

Which of these statements describes vasoconstriction

A)It causes a decrease in resistance.
B)It occurs when there is a decrease in the radius of a vessel.
C)It is due to a decrease in sympathetic activity.
D)It causes no change in resistance.

Question 13

Which statement applies to vasoconstriction

A)an increase in the radius of a vessel
B)decreases blood flow through an arteriole
C)increases blood flow through an arteriole
D)can be caused in an arteriole by parasympathetic activation

Question 14

What is the major function of the arterioles

A)to regulate flow of blood through capillary beds
B)to distribute cardiac output to large blood vessels
C)to serve as a pressure reservoir
D)to regulate heart rate

Question 15

What are the major resistance vessels of the body

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

Question 16

Which organ receives the most blood flow while at rest

A)heart
B)kidney
C)brain
D)muscle

Question 17

Which statement describes mean arterial pressure

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

Question 18

If the pulse pressure is 44 mmHg, and the diastolic pressure is 68 mmHg, what is the systolic pressure

A)22 mmHg
B)24 mmHg
C)66 mmHg
D)112 mmHg

Question 19

Which of these statements describes arteries

A)They serve as rapid-transit passageways from the tissues to the heart because of their large radii.
B)They act as a blood reservoir because they have the capacity to store large volumes of blood with little change in their internal pressure.
C)They act as a pressure reservoir to provide the driving force for blood when the heart is relaxing.
D)They are the site of exchange between the blood and the surrounding tissues.

Question 20

Under which of these circumstances does vascular resistance increase

A)when radius decreases
B)when length decreases
C)when viscosity decreases
D)when haematocrit decreases

Question 21

As metabolic activity of an organ or tissue increases, blood flow to that organ increases.What is the term for this phenomenon

A)pressure autoregulation
B)tissue anoxia
C)active hyperaemia
D)hypertension

Question 22

What is endothelium-derived relaxing factor (EDRF)

A)a local chemical mediator released from the endothelial cells that induces contraction of arteriolar smooth muscle in the vicinity
B)adenosine
C)nitric oxide
D)carbon dioxide released from the endothelial cells

Question 23

Which of these local chemical factors will NOT cause vasodilation of arterioles

A)decreased K⁺
B)increased CO₂
C)increased acid
D)decreased O₂

Question 24

Which of these tissues does NOT have increased blood flow during exercise

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

Question 25

What is released by most sympathetic fibres at the arterioles

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

Question 26

What is the mean arterial blood pressure when the blood pressure is recorded as 117/78

A)91 mmHg
B)97.5 mmHg
C)100 mmHg
D)117 mmHg

Question 27

Which of these factors would decrease total peripheral resistance

A)adrenal medulla hormones
B)angiotensin II
C)increased haematocrit
D)anaphylaxis

Question 28

Which of these factors does NOT cause arteriolar vasodilation

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

Question 29

Which of these local factors does NOT produce the relaxation of arteriolar smooth muscle

A)increased acid
B)increased carbon dioxide
C)increased osmolarity
D)increased oxygen

Question 30

Which of these properties does NOT refer 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.

Question 31

Which of these factors would produce the greatest increase 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

Question 32

Where and why does blood flow increase during strenuous exercise

A)in the heart because of local control factors
B)in the brain because of reflex control factors
C)in the skeletal muscles because of local control factors
D)in the lungs because of local control factors

Question 33

Which of these statements describes why increased respiration within a tissue leads to vasodilation of arterioles

A)Carbon dioxide levels increase.
B)Oxygen levels increase.
C)Parasympathetic activity increases.
D)Sympathetic activity increases.

Question 34

In an arteriole, if the blood vessel radius is two units and then is vasoconstricted to one unit, what is the result

A)The resistance decreases 16 times.
B)The resistance increases 16 times.
C)Flow will be increased.
D)Flow will be neither increased nor decreased.

Question 35

Which of these local chemical changes does NOT occur during a period of increased cell activity

A)increased CO₂
B)increased acid
C)increased O₂
D)increased K⁺

Question 36

Which of these factors is the 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 that tissue.
B)Parasympathetically induced vasodilation of the capillaries within a tissue allows more blood to flow into that tissue.
C)Local changes within a tissue resulting from increased metabolic activity can produce local arteriolar vasodilation to allow more blood to flow into that tissue.
D)Widespread venous vasoconstriction allows blood to dam up at the tissue level.

Question 37

Which of these statements applies to extrinsic control of arteriolar radius

A)It is accomplished primarily by the parasympathetic nervous system.
B)It is important in the regulation of arterial blood pressure.
C)It can never be overridden by local adjustments.
D)It is important for oxygen delivery to tissues.

Question 38

What does the myogenic response refer to

A)vascular smooth muscle's tendency to constrict when blood flow increases
B)vascular smooth muscle's tendency to relax when blood flow increases
C)vascular smooth muscle's tendency to constrict when stretched
D)vascular smooth muscle's tendency to dilate when stretched

Question 39

Which of these statements does NOT apply to nitric oxide

A)It increases total peripheral resistance by its action on arteriolar smooth muscle.
B)It serves as endothelium-derived relaxing factor.
C)It is the direct mediator of penile erection.
D)It is released as "chemical warfare" by macrophages of the immune system.

Question 40

How do the larger arteries assist with systemic blood flow to tissues

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

Question 41

Which principal force causes movement of fluid from tissues into capillaries

A)hydrostatic pressure of venous capillaries
B)hydrostatic pressure of arterial blood
C)osmotic pressure created by plasma proteins
D)pressure of the lymph

Question 42

Which of these types of blood vessels consists of only one cell layer

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

Question 43

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

A)arteriole
B)capillary
C)metarteriole
D)artery

Question 44

Which of these statements describes velocity of blood flow in capillaries

A)It is greater than that for arterioles.
B)It is greater than that for veins.
C)It is slow enough to favour adequate exchange.
D)It is less than that for arterioles.

Question 45

Which of the following happens when blood pressure becomes elevated to above normal

A)The carotid sinus and aortic arch baroreceptors decrease their rate of firing.
B)The cardiovascular control centre decreases sympathetic and increases parasympathetic activity to the heart and blood vessels.
C)Arteriolar vasoconstriction occurs as a compensatory response.
D)It causes salt retention to occur in the kidneys.

Question 46

Under which of these conditions will reabsorption occur

A)when inward-driving pressures exceed outward-driving pressures across the capillary wall
B)when outward-driving pressures exceed inward-driving pressures across the capillary wall
C)when the osmolarity of plasma is decreased in the venule end of the capillary
D)when the outward-driving pressures and the inward-driving pressures across the capillary wall are equal

Question 47

Which of the following is NOT a short-term adjustment for blood pressure

A)baroreceptor reflex
B)change in cardiac output
C)renal activity
D)hormone

Question 48

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

A)increase in cardiac output
B)decrease in total peripheral resistance
C)increase in heart rate
D)venous vasoconstriction

Question 49

What does microcirculation comprise

A)arteries, arterioles, and capillaries
B)arterioles, capillaries, and venules
C)arteries, capillaries, and venules
D)arteries, arterioles, and venules

Question 50

Through which of these vessels is the velocity of blood flow the slowest

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

Question 51

Which of these statements does NOT apply to blood pressure

A)It is maximal during ventricular systole.
B)It decreases farther away from the heart.
C)It increases with increasing resistance.
D)It can be increased by direct parasympathetic activity.

Question 52

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

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

Question 53

Which of these factors does NOT promote the function of the capillaries

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

Question 54

Which of the following is NOT a characteristic feature of capillaries

A)thin walls
B)short distance between adjacent vessels
C)distensible walls
D)slow blood velocity

Question 55

What is the primary method by which materials such as O₂, CO₂, and nutrients are exchanged between blood and the 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)the processes of ultrafiltration and reabsorption

Question 56

Which of these terms refers to a chronic state of increased arterial pressure

A)shock
B)congestive heart failure
C)pulmonary oedema
D)hypertension

Question 57

Which of these factors is the major determinant influencing resistance to blood flow

A)viscosity of the blood
B)radius of the vessel through which the blood is flowing
C)pressure gradient in the vessel
D)haematocrit

Question 58

Which of these statements describes active hyperaemia

A)arteriolar dilation that occurs within a tissue in response to local chemical changes that accompany increased metabolic activity of that tissue
B)local arteriolar mechanisms that are aimed at keeping tissue blood flow 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 that tissue's blood supply
D)important in maintaining an adequate pressure head to drive blood forward into a tissue

Question 59

What does binding of epinephrine to alpha receptors cause

A)smooth muscle constriction in all arteries
B)smooth muscle relaxation in skeletal muscle arteries
C)smooth muscle constriction in skeletal muscle arteries
D)smooth muscle relaxation in coronary arteries

Question 60

Which two pressures act to move fluid into capillaries

A)interstitial fluid hydrostatic pressure and capillary blood pressure
B)plasma-colloid osmotic pressure and interstitial fluid-colloid osmotic pressure
C)interstitial fluid hydrostatic pressure and plasma-colloid osmotic pressure
D)interstitial fluid hydrostatic pressure and interstitial fluid-colloid osmotic pressure

Question 61

Which of these changes will increase fluid reabsorption by the capillaries

A)decrease in interstitial fluid hydrostatic pressure
B)increase in capillary blood pressure
C)increase in plasma-colloid osmotic pressure
D)increase in interstitial fluid-colloid osmotic pressure

Question 62

Which of these alterations could lead to oedema

A)a fall in capillary blood pressure
B)a fall in the concentration of plasma proteins
C)a dilation of lymph vessels
D)an increase in plasma osmolarity

Question 63

Varicose veins develop mainly from the incompetent function of which of these structures

A)connective tissue lining
B)endothelium
C)elastic tissues
D)venous valves

Question 64

Which of these factors is NOT involved in promoting venous return to the heart

A)Parasympathetic stimulation decreases venous pressure.
B)The skeletal muscle pump squeezes blood through the veins.
C)The respiratory pump provides a pressure gradient between the lower and chest veins.
D)There is vasodilation of veins.

Question 65

What is the primary reason that oedema may occur with serious burns

A)increased venous pressure due to interference with circulation through scarring in the burned area
B)lowering of plasma-colloid 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

Question 66

Which of these statements describes venous valves

A)They actively contract to force blood uphill against gravity.
B)They passively close to prevent the backflow of blood in the veins.
C)They are positioned at the entrances to the ventricles.
D)They are two-way valves.

Question 67

Which of these terms regarding the effects of sympathetic stimulation on blood pressure are NOT paired correctly

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

Question 68

If arterial pressure is elevated, which of these responses will baroreceptor signals trigger

A)a fall in plasma angiotensin II levels
B)increased activity in sympathetic nerves, causing peripheral vasoconstriction
C)an increase in epinephrine secretion from the adrenal medulla
D)increased total peripheral resistance

Question 69

Which of these statements applies to veins

A)Their walls are highly muscular.
B)Their walls consist of thick layers of elastic tissues.
C)They serve as a blood reservoir.
D)They transport blood away from the heart.

Question 70

Which of these vessels contain the highest percentage of total blood volume

A)pulmonary veins
B)pulmonary arteries
C)systemic veins
D)systemic arteries

Question 71

Which of the following is NOT a function of the lymphatic system

A)to defend against disease
B)to return fluid to the circulatory system
C)to transport fat molecules
D)to regulate sodium balance

Question 72

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 mmHg
Plasma-colloid osmotic pressure = 23 mmHg
Interstitial fluid hydrostatic pressure = 1 mmHg
Interstitial fluid-colloid osmotic pressure = 0 mmHg

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

Question 73

Which of the following will NOT cause an increase in blood pressure

A)increased levels of aldosterone
B)increased levels of angiotensin II
C)increased blood volume
D)increased levels of oxygen

Question 74

Which of these vessels can act as blood reservoirs by adjusting their total capacity to accommodate variations in blood volume

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

Question 75

Heart and venous valves serve a similar function.What type of flow do they prevent

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

Question 76

Given the following parameters, what would the reabsorption pressure be
Blood capillary pressure at arteriolar end of tissue capillaries = 35 mmHg
Blood capillary pressure at venule end of tissue capillaries = 15 mmHg
Plasma-colloid osmotic pressure = 22 mmHg
Interstitial fluid hydrostatic pressure = 1 mmHg
Interstitial fluid-colloid osmotic pressure = 0 mmHg

A)6 mmHg
B)7 mmHg
C)8 mmHg
D)10 mmHg

Question 77

Which of these statements does NOT apply to veins

A)They act as low-resistance passageways for blood flow from the tissues to the heart.
B)They always contain deoxygenated blood.
C)They contain one-way valves that prevent the backflow of blood.
D)Their walls are thinner than those of arteries.

Question 78

Which of these conditions can cause oedema

A)blockage of lymph vessels, increased capillary blood pressure, and decreased plasma-colloid osmotic pressure
B)blockage of lymph vessels and decreased capillary blood pressure
C)increased capillary blood pressure and increased plasma-colloid osmotic pressure
D)dilation of lymph vessels and decreased plasma-colloid osmotic pressure

Question 79

What is the location of the receptors that detect changes in blood pressure

A)carotid sinus
B)spinal cord
C)hypothalamus
D)medulla

Question 80

Which of these conditions might NOT be associated with oedema

A)extensive burns
B)congestive heart failure
C)decreased venous pressure
D)lymphatic obstruction