Deck 8: Vascular Physiology

Question 1

Which of the following statements concerning the pulse pressure is correct?

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

Answer 1

A

Question 2

What does microcirculation comprise?

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

Answer 2

B

Question 3

Which of the following is correct for 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.

Answer 3

B

Question 4

What 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 the following is correct for the major function of the arterioles?

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

Question 6

What 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 of the blood

Question 7

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

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

Question 8

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

A) The resistance decreases 16 times.
B) The resistance increases 16 times.
C) Flow will be increased.
D) There is no effect on blood flow.

Question 9

What is vascular resistance related to ?

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

Question 10

Which statement is correct for 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 11

Which of the following types of blood vessel consists of only one cell layer?

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

Question 12

Which of the following is the correct 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/resistance

Question 13

Which statement is correct for 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 proportionate to the blood viscosity.
D) It is increased when blood vessel length is shorter.

Question 14

Which statement concerning vasoconstriction is correct?

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

Question 15

When does vascular resistance increase?

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

Question 16

Which of the following 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 17

Which of the following is correct for the 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 surrounding tissues.

Question 18

Which organ receives the most blood flow at rest?

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

Question 19

Which statement is INCORRECT of 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 can be increased by direct parasympathetic activity.

Question 20

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,for maintaining blood flow during diastole?

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

Question 21

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 22

Which of the following is correct for 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 the oxygen delivery to the tissues.

Question 23

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.

Question 24

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

A) 48 mm Hg
B) 93 mm Hg
C) 100 mm Hg
D) 108 mm Hg

Question 25

Which of the following 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 26

Which of the following 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 27

Which statement about nitric oxide is INCORRECT?

A) It increases the total peripheral resistance by its action on arteriolar smooth muscle.
B) It serves as endothelial-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 28

What is released by most sympathetic fibres at the arterioles?

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

Question 29

Which of the following local chemical factors will NOT cause vasodilation of arterioles?

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

Question 30

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 hyperemia
D) Hypertension

Question 31

Why does increased respiration within a tissue lead to vasodilation of arterioles?

A) Carbon dioxide levels increase.
B) Oxygen levels increase.
C) Parasympathetic activity increases.
D) of smooth muscle contraction of the walls of arterioles

Question 32

What is endothelial-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

Question 33

What are the major resistance vessels of the body?

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

Question 34

During strenuous exercise,where does blood flow increase?

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

Question 35

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.

Question 36

If the pulse pressure is 44 mm Hg and the diastolic pressure is 68 mm Hg,what is the systolic pressure?

A) 22 mm Hg
B) 24 mm Hg
C) 66 mm Hg
D) 112 mm Hg

Question 37

Which of the following 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 38

Which statement is correct for mean arterial pressure?

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

Question 39

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

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

Question 40

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.

Question 41

Given the following parameters,what would the reabsorption pressure be?
- 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

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

Question 42

Which principle force causes movement of fluid from the tissues into the capillaries?

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

Question 43

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-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 44

Which two pressures act to move fluid into the capillary?

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

Question 45

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

A) Aorta
B) Arterioles
C) Capillaries
D) Veins

Question 46

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 47

Which statement is true about 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 48

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.

Question 49

What can edema result from?

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

Question 50

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) concentration of glucose in the capillary

Question 51

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

Question 52

What does binding of epinephrine to alpha receptors cause?

A) smooth muscle relaxation in 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 53

What is Active hyperaemia?

A) It 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) It 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) It refers to the increase in blood flow to a tissue that occurs after removal of an occlusion of its blood supply.
D) It is important in maintaining an adequate pressure head to drive blood forward into a tissue.

Question 54

Which of the following tissues do NOT have an increased blood flow during exercise?

A) skeletal muscles
B) Heart
C) Skin
D) Brain

Question 55

Where is the largest total cross-sectional area found?

A) Aorta
B) Arterioles
C) Capillaries
D) Veins

Question 56

Which change will increase fluid reabsorption by the capillaries?

A) decreased interstitial-fluid hydrostatic pressure
B) increased capillary blood pressure
C) increased blood-colloid osmotic pressure
D) increased interstitial-fluid-colloid osmotic pressure

Question 57

When will reabsorption occur?

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

Question 58

Which of the following factors would decrease total peripheral resistance?

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

Question 59

Which of the following is correct for the process of ultrafiltration?

A) It is movement of protein-free plasma from the interstitial fluid into the capillaries.
B) It occurs when the outward forces (capillary blood pressure plus interstitial-fluid-colloid osmotic pressure) exceed the inward forces (blood-colloid osmotic pressure plus interstitial-fluid hydrostatic pressure).
C) It occurs when the outward forces (capillary blood pressure plus blood-colloid osmotic pressure exceed the inward forces (interstitial-fluid hydrostatic pressure plus interstitial-fluid-colloid osmotic pressure).
D) It is movement of protein-free plasma from the interstitial fluid into the arterioles.

Question 60

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) dilated lymph vessels
D) increased plasma osmolarity

Question 61

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 62

Which of the following is correct for mean arterial blood pressure?

A) It equals stroke volume times heart rate.
B) It is 91 mm Hg when the blood pressure is recorded as 117/78.
C) It is 97.5 mm Hg when the blood pressure is recorded as 117/78.
D) It is 100 mm Hg when the blood pressure is recorded as 117/78.

Question 63

Which statement is INCORRECT for the 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 64

Which of the following is NOT for short-term adjustments in blood pressure?

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

Question 65

Where are the receptors that detect changes in the blood pressure?

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

Question 66

What is NOT a function of the lymphatic system?

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

Question 67

How does the vasomotor centre respond to rising H⁺/CO₂?

A) by vasodilating arteries
B) by vasoconstricting arteries
C) by increasing respiratory rate
D) by inhibiting cardioinhibitory centre

Question 68

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.

Question 69

Which of the following factors does NOT promote the function of the capillaries?

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

Question 70

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

A) Forward
B) Backward
C) turbulent
D) Pulsatile

Question 71

Which factor does not positively affect blood pressure?

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

Question 72

Which factor 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 73

Regulation of arterial pressure is mediated by reflex mechanisms.One important pressure receptor,a _____,is located in the _____.

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

Question 74

Which of the following conditions might be NOT associated with edema?

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

Question 75

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

Question 76

Which statement regarding effects of sympathetic stimulation 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.

Question 77

What happens when blood pressure becomes elevated 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) Salt retention occurs in the kidneys.

Question 78

Which are the two determinants of mean arterial pressure?

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

Question 79

Which statement concerning the venous valves is correct?

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 80

Which vessels contain the highest percentage of total blood volume?

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