Download Cardiovascular STUDY Questions for Dentistry and

Cardiovascular STUDY Questions for Dentistry and Optometry Courtesy of Dr. HN Mayrovitz
Please note that a certain percentage of these questions may be used as is or slightly modified in your
Cardiovascular Exam exam. Please also note that these are study questions designed to give you a flavor for
question structure and to help you focus on areas of study. Most of these questions should be answerable from
the notes, lectures and reading. Generally speaking answers will not be given. For those of you who have earnestly
tried and can not answer a specific question or questions you may arrange to meet with Dr. Mayrovitz by setting
up an appointment via email.
1. Increased sympathetic activation of myocyte β1 receptors results in which of the following effects?
A. Positive dromotropic
B. Coronary artery vasoconstriction
C. Negative chronotropic
D. Negative lusitropic
E. Decreased stroke volume
2. Mean aortic pressure (MAP):
A. Is the time average of the pulsatile aortic blood flow
B. Increases if total peripheral resistance decreases
C. Is inversely related to cardiac output
D. Depends on both systolic and diastolic pressures
E. Is about twice that of the pulmonary artery mean pressure
3. The percentage of a fixed cardiac output (CO) that goes to an organ depends on:
A. The value of MAP
B. The value of CO
C. The value of the Heart Rate
D. Organ absolute vascular resistance
E. Organ relative vascular resistance
4. Which of the following is a true statement?
A. Cardiac output (CO) is the volume of blood ejected per beat
B. Pulmonary blood pressures are normally greater than systemic blood pressures
C. The term ‘CO distribution’ is used to describe the ml/min of blood flow to an organ
D. On average, cardiac output equals venous return
E. Left and right ventricles are functionally in parallel with each other
5. Cardiac action potential (AP) conduction speed is:
A. Increased by vagal impulses to the SA node
B. Slowest in the atrial muscle fibers
C. Decreased by sympathetic impulses to the AV node
D. Slowest in the AV node
E. Slowed by sympathetic impulses to myocardial β1 receptors
6. Which of the following best describes conditions within a vascular bed of an organ?
A. All capillaries are effectively in series with each other
B. All arterioles are effectively in parallel with the capillaries they supply
C. The greatest pressure loss is attributable to the small lumen of the capillaries
D. All arterioles are effectively in series with each other
E. A decrease in the number of arterioles leads to an increase in the organ’s total resistance
7. Shear stress caused by blood flow in a vessel is:
A. Greatest at the center of the vessel
B. Greatest at the wall of the vessel
C. Inversely proportional to the average blood velocity
D. Directly proportional to the vessel’s diameter
E. Increased if blood’s viscosity decreases
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Cardiovascular STUDY Questions for Dentistry and Optometry Courtesy of Dr. HN Mayrovitz
8. In which site does the mean blood pressure normally have its least value?
A. Arterioles
B. Capillaries
C. Right Atria
D. Venules
E. Pulmonary artery
9. The elastin to collagen ratio is normally greatest in the walls of:
A. Arterioles
B. Venules
C. Muscular arteries
D. Large arteries
E. Large veins
10. If arterial systolic and diastolic pressures are measured to be 150 and 90 mmHg respectively, then the mean
arterial pressure (MAP) is:
A. 60 mmHg
B. 80 mmHg
C. 110 mmHg
D. 120 mmHg
E. 150 mmHg
11. Which of the following best describes features in an arteriole with a blood flow Q?
A. Blood velocity is largest at its wall
B. Shear stress is largest at its wall
C. Shear stress at its wall is inversely related to Q
D. Average blood velocity is directly related to cross sectional area
E. Shear rate is greatest at the vessel center
12. In which site does the mean blood velocity normally have the least value?
A. Arterioles
B. Capillaries
C. Venules
D. Large veins
E. Central veins
13. Turbulent blood flow:
A. Is a normal feature in most large arteries
B. Causes an increase in resistance to blood flow
C. Occurs if the Reynolds number is below the critical threshold
D. Reduces the amount energy lost as compared to laminar flow
E. Causes blood flow to be inversely related to perfusion pressure
14. Blood’s viscosity in a blood vessel increases if:
A. Shear rate decreases
B. Hematocrit decreases
C. Average blood velocity increases
D. Blood temperature increases
E. Either C or D occurs
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Cardiovascular STUDY Questions for Dentistry and Optometry Courtesy of Dr. HN Mayrovitz
15. The compliance of an artery will decrease if:
A. The wall’s elastic modulus decreases
B. Sympathetic impulses to its wall decrease
C. The elastin/collagen ratio in its wall increases
D. The wall thickness to diameter ratio increases
E. Either C or D occurs
16. According to the modified Laplace’s Law, stress in a blood vessel wall:
A. Has units of force per unit wall length
B. Has units of force per unit wall volume
C. Increases if the radius to wall thickness ratio increases
D. Increases if its transmural pressure decreases
E. Increases if its intravascular pressure decreases
For the next question refer to the figure below that represents a vascular model of an organ.
MAP
RA
RV
CVP
17. Which of the following decreases blood flow and also increases capillary pressure?
A. Arteriolar vasoconstriction
B. Decreased MAP
C. Venous vasoconstriction
D. Increased CVP
E. Both C and D
18. Which ionic current is mainly responsible for C0 of the SA node action potential?
A. Na
B. K
C. K1
D. Ca-L
E. Ca-T
19. A Purkinje action potential’s C2 results mainly due to a balance between which currents?
A. Na and K
B. K and Ca
C. K1 and Na
D. K1 and Ca
E. K and K1
20. The rate of C4 depolarization of the SA node action potential will increase if:
A. If decreases
B. ICa-L decreases
C. ICa-T decreases
D. IK decreases
E. Either C or D occurs
21. if vagal impulses to the SA node are increased, which of the following occurs?
A. Heart rate increases
B. The cell membrane potential becomes more positive
C. The Funny current (If) is increased
D. A potassium current is increased
E. Ach is rapidly removed by cholinesterase
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Cardiovascular STUDY Questions for Dentistry and Optometry Courtesy of Dr. HN Mayrovitz
22. The vulnerable period occurs during which part of the EKG?
A. P-wave
B. QRS complex
C. T-Wave
D. ST interval
E. PR interval
23. Considering fast response action potentials, which of the following is most likely to have the slowest
conduction speed?
A. An action potential with and increased amplitude
B. An action potential with an increased rate of rise of C0
C. An action potential in which both amplitude and rate of rise are increased
D. An action potential in which many fast sodium channels are blocked
E. An action potential in which many long lasting calcium channels are blocked
24. Which of the following occurs in the closest time synchrony with the QRS of the EKG?
A. Phase 0 of the SA node action potential
B. Phase 0 of the ventricular muscle action potential
C. Phase 3 of the ventricular muscle action potential
D. Phase 3 of the SA node action potential
E. Phase 4 of the AV node action
25. The intact heart parameter that most closely represents the stretch of muscle fibers at the onset of ventricle
contraction is:
A. End systolic volume
B. End systolic pressure
C. End diastolic volume
D. End diastolic pressure
E. The peak isovolumic pressure line
26. An increase in stroke volume that occurs at a fixed preload is most likely due to:
The Frank-Starling mechanism
An increase in myocardial contractility
An increase in afterload
An increase in heart rate
27. The threshold level of ejection fraction below which it is considered to be definitely abnormally low is:
A. 35%
B. 40%
C. 45%
D. 50%
E. 55%
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Cardiovascular STUDY Questions for Dentistry and Optometry Courtesy of Dr. HN Mayrovitz
For the next 3 questions use figure 1 which shows the aortic, atrial and ventricular pressures.
28. Which point is closest in time to the QRS of the EKG?
A. A
B. B
C. C
D. D
E. E
29. Between which points is ventricular energy demand greatest?
A. C-A
B. A-D
C. D-B
D. B-E
E. A-B
Figure 1
3
D
Aortic
A2
4
B
Atrial
Ventricle
E
1
C
30. Closest to which point is the second heart sound heard?
A. A
B. B
C. C
D. D
E. E
31. Which of the following describes a blood pressure classed as normal?
A. Systolic less than 130 and diastolic less than 85 mmHg
B. Systolic less than 125 and diastolic less than 80 mmHg
C. Systolic less than 120 and diastolic less than 80 mmHg
D. Systolic less than 115 and diastolic less than 85 mmHg
E. Systolic equal to 120 and diastolic equal to 80 mmHg
For the next three questions refer to Mary’s ventricular pressure-volume loop in figure 2.
33. Mary’s aortic systolic pressure is:
A. Less than 120 mmHg
B. Between 60 and 90 mmHg
C. Equal to 100 mmHg
D. Between 150 and 200 mmHg
E. Between 60 and 120 mmHg
34. Mary’s end systolic volume is:
A. 60 ml
B. 100 ml
C. 120 ml
D. 160 ml
E. Greater than 90 ml
160
Figure 2
100
LV Pressure (mmHg)
32. Mary’s ejection fraction is closest to:
A. 33.3%
B. 40%
C. 50%
D. 60%
E. 66.6%
90
60
30
0
60
90
120
LV Volume (ml)
5
Cardiovascular STUDY Questions for Dentistry and Optometry Courtesy of Dr. HN Mayrovitz
35. Which of the following is not usually a factor that contributes to maintaining essential hypertension?
A. Increased cardiac output
B. Increased blood volume
C. Microvessel rarefaction
D. Increased total peripheral resistance
36. Which of the following best describes blood flow through AV shunts in the skin?
A. It increases if sympathetic impulses to them increase
B. If increased, it causes an increase in the delivery of oxygen to skin cells
C. It increases if the environmental temperature is sufficiently hot
D. It Increases if precapillary sphincters dilate
E. It is best described by both C and D
37. The blood brain barrier occurs largely due to which feature of cerebral capillaries?
A. Discontinuous intercellular junctions
B. Fenestrated intercellular junctions
C. Particularly tight continuous junctions
D. Low capillary oncotic pressure
E. High arteriolar resistance
38. Which of the following tends to increase fluid filtration from capillaries?
A. Increased capillary oncotic pressure
B. Increased tissue oncotic pressure
C. Increased tissue hydrostatic pressure
D. Increased protein concentration in capillaries
E. Increased arteriolar resistance
39. Which of the following will decrease the tendency for fluid filtration from capillaries?
A. Pre-capillary vasodilation
B. Post-capillary vasodilation
C. Increased mean arterial pressure
D. A decreased ratio of pre-capillary resistance to post-capillary resistance
E. inflammation
40. The calf muscle pump decreases:
A. Pressure in foot veins
B. Heart rate
C. Venous return
D. Blood volume in leg veins
E. Both A and D
41. At what approximate transmural pressure do large veins become circular in shape?
A. Less than about 4 mmHg
B. Around 4 mmHg
C. Around 8 mmHg
D. Around 12 mmHg
E. Greater than about 15 mmHg
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Cardiovascular STUDY Questions for Dentistry and Optometry Courtesy of Dr. HN Mayrovitz
42. Changes in ventricular blood flow associated with increased HR are caused mainly by:
A. Myogenic Response
B. Autoregulation
C. Active hyperemia
D. Reactive hyperemia
E. Increased sympathetic impulses
43. Maintenance of cerebral blood despite changes in its perfusion pressure depends on:
A. Myogenic Response
B. Autoregulation
C. Active hyperemia
D. Reactive hyperemia
E. Functional hyperemia
44. In arterioles with myogenic response features, increasing transmural pressure causes:
A. Active vasodilation
B. Active vasoconstriction
C. A passive reduction in their diameter
D. A passive decrease in their vascular resistance
E. Both A and C
45. Which is an endothelial cell derived substance that is the most potent vasoconstrictor?
A. Nitric oxide
B. Norepinephrine
C. Endothelin
D. Angiotensin II
E. Prostacyclin
46. Which one of the following statements is true?
A. Carotid sinus (CS) baroreceptor gain is greatest at about 120 mmHg
B. High levels of blood CO2 cause a carotid body induced hypotension
C. CS baroreceptors are normally the most important controller of long term blood pressure
D. CS baroreceptor afferent nerve traffic increases if the rate of pressure change increases
47. A large drop in aortic blood pressure triggers which carotid sinus baroreceptor reflex?
A. Decreased nerve traffic to arterioles in skeletal muscle
B. Decreased nerve traffic to ventricular myocardium
C. Increased nerve traffic to systemic peripheral veins
D. Increased nerve traffic to cerebral arterioles
E. Increased nerve traffic to coronary arterioles
48. Mary has a breathing problem that causes her arterial blood CO2 to rise rapidly and dramatically.
As a result, which of the following reflex changes would initially occur?
A. Mean aortic pressure decreases
B. Total peripheral resistance falls
C. Sympathetic activity to skin arterioles increases
D. Sympathetic activity to skeletal muscle arterioles decreases
7
Cardiovascular STUDY Questions for Dentistry and Optometry Courtesy of Dr. HN Mayrovitz
49. Increased atrial myocyte stretch causes these cells to:
A. Release atrial natriuretic peptide
B. Trigger the kidney to reduce urine output
C. Trigger the hypothalamus to release of greater amounts of vasopressin
D. Trigger the hypothalamus to release greater amounts of antidiuretic hormone
E. Trigger the kidney to conserve more water
50. Increased stretch of low pressure venoatrial receptors causes:
A. Sympathetic impulses to the kidney to increase
B. Heart Rate to increase
C. Blood volume to increase
D. Urine output to decrease
E. Renal vascular resistance to increase
51. In a normal vasculature, which of the following best describes the mean aortic pressure (MAP)?
A. It is the time average of the pulsatile aortic blood flow
B. It Is equal to one half the sum of the systolic and diastolic pressures
C. For a fixed TPR is value Is inversely related to cardiac output
D. It’s value is similar in most large arteries
E. its value is about twice that of the pulmonary artery mean pressure
52. Assuming cardiac output (CO) is fixed, the percentage of CO that goes to an organ depends on:
A. The value of MAP
B. The value of CO
C. The value of total peripheral resistance (TPR)
D. The organ’s absolute vascular resistance
E. The organ’s relative vascular resistance
53. Which of the following best describes conditions within a vascular bed of an organ?
A. All capillaries are effectively in series with each other
B. All arterioles are effectively in parallel with the capillaries they supply
C. The greatest pressure loss is attributable to the small lumen of the capillaries
D. All arterioles are effectively in series with each other
E. A decrease in the number of arterioles leads to an increase in the organ’s total resistance
54. An angiogram of a thoracic aorta shows a longitudinal pattern as shown in the figure. The vertical lines define
the sections of interest. With this image as reference, which one of the following statements is true?
A.
B.
C.
D.
E.
Blood flow (Q) is greater in section 1 than in section 2
Average blood velocity is greater in section 1 than in section 3
Reynolds number is greater in section 1 than in section 2
Pressure loss across section 4 is greater than across section 1
Resistance of section 3 is greater than that of section 2
Q
1
2
3
4
8
Cardiovascular STUDY Questions for Dentistry and Optometry Courtesy of Dr. HN Mayrovitz
55. A vascular bed has a constant perfusion pressure of 100 mmHg. Initially the measured blood flow is 100 ml/min
as shown in figure A below. Initial pre- and post- capillary resistances are 0.80 and 0.20 pru respectively as shown.
A vasoactive drug is then given that results in the resistances shown in figure B.
Which one of the following statements is true about the drug’s action?
A.
B.
C.
D.
E.
It caused an increase in blood flow
It caused an increase in capillary pressure
It caused a decrease in total vascular resistance
It caused arteriolar vasoconstriction
It caused venous vasodilation
100 ml/min
B
A
100
mmHg
0.80
0.50
0.20
0.50
56. The viscosity of blood flowing in a venule tends to increase if there is an increase in:
A. average blood velocity
B. average shear rate
C. radial velocity gradient
D. hematocrit
E. temperature
For the next question refer to the
Aorta
adjacent figure, which shows five
Flow
hypothetical organs that lie between the
12
8
12
aorta and a central vein. Each organ’s
PC
PC
PC
complete vascular bed is represented by a
pre-capillary and post-capillary part with
6
2
2
PC as the mid-capillary pressure. Values in
boxes are resistances in pru. Initial mean
Vein
1
2
3
aortic pressure (MAP) is 100 mmHg and
mean pressure in the vein is 0 mmHg. Flow in the figure is the cardiac output (CO).
100 mmHg
8
10
PC
PC
4
4
4
5
0 mmHg
57. With reference to the above figure, In which organ is blood flow the greatest?
A. 1
B. 2
C. 3
D. 4
E. 5
58. A drug increases MAP and simultaneously decreases TPR.
The drug’s action is best explained if it also causes an increase in:
A. Systemic hematocrit
B. Peripheral vasoconstriction
C. Peripheral vasodilation
D. Cardiac output
E. Heart Rate
9
Cardiovascular STUDY Questions for Dentistry and Optometry Courtesy of Dr. HN Mayrovitz
For the next question refer to the figure below representing a ventricular muscle fast response action potential
(AP)
59. At or near point y:
++
Inward Ca current achieves its largest value
IK1 achieves its largest value
Myocardial cells enter their absolute refractory period
The T-wave of the EKG starts
The ventricular septum starts to depolarize
x
A.
B.
C.
D.
E.
y
60. Which of the following will decrease the rate of spontaneous depolarization of the SA node?
A. Increased funny current (If)
B. Decreased inward calcium current
C. Decreased outward potassium current
D. Increased sympathetic stimulation of the node
E. Decreased vagal stimulation of the node
61. Reduced heart rate that accompanies vagus stimulation of the SA node is due in part to:
A. activation of β 1 receptors
B. an indirect action of norepinephrine on M2 receptors
C. a partial depolarization of nodal tissue cell membranes
D. a decrease in IK,ACh
E. partial hyperpolarization of nodal tissue cell membranes
62. An increase in myocardial contractility causes which of the following to also increase?
A. End diastolic volume (EDV)
B. Preload
C. Maximum rate of ventricular pressure development (dP/dt)
D. Duration of the ventricular pressure pulse
E. Heart rate
63. As a consequence of the Frank-Starling mechanism, a decrease in preload will result in:
A. a decrease in stroke volume
B. an increase in stroke work
C. an increase in contractility
D. a decrease in contractility
E. an increase in peak isovolumic pressure
64. Which one of the following tends to decrease aortic pulse pressure?
A.
An increase in aortic compliance
B.
An increase in calcium deposition in the aortic wall
C.
An increase in rate of ejection from the left ventricle
D.
An increase in stroke volume
E.
An increase in cardiac contractility
65. Which of the following is a true statement regarding the venous system?
A.
Compliance is high at both very low and very high transmural pressures (TMP).
B.
Sympathetic stimulation causes an increase in compliance
C.
If TMP is less than about 4 mmHg, vessels tend to be fully circular
D.
Sympathetic stimulation tends to move blood out of peripheral veins
E.
Peripheral leg veins tend to collapse during the standing position
10
Cardiovascular STUDY Questions for Dentistry and Optometry Courtesy of Dr. HN Mayrovitz
66. A person who is standing as compared to being supine will normally have:
A. A greater central venous pressure
B. A greater cardiac output
C. A reduced stroke volume
D. A greater left ventricular filling pressure
E. A greater venous return
67. Which of the following occurs in response to a large blood volume loss?
A. Tachycardia due to the Bainbridge reflex
B. Reduced renin release due to sympathetic activity on renal C2 receptors
C. Increased renal blood flow due to sympathetic activity on renal arteriole CCreceptors
D. Increased urine output due to elevated levels of aldosterone
E. Increased TPR due to increased levels of antidiuretic hormone (ADH)
68. Which of the following tends to cause tissue edema?
A. An increase in sympathetic activity to arterioles that supply the capillaries
B. A prolongation of the constriction phase of arteriolar rhythmic vasomotion
C. An arterial obstruction caused by a stenosis
D. A venous obstruction caused by a thrombosis
E. A reduction in the protein concentration in the interstitial space
69. Which one of the following statements is true?
A. While standing, pressure in the dural sinuses is greater than in the central veins
B. While standing, pressure in the central veins is greater than in the leg veins
C. During respiratory expiration, venous return increases
D. Increased sympathetic activation of peripheral veins inhibits venous return
E. Shifting from a standing to a supine position increases central venous pressure
70. A sudden decrease in aortic blood pressure triggers which high pressure baroreceptor reflex?
A. Increased afferent nerve activity from the carotid sinus.
B. Decreased nerve activity to skeletal muscle and skin arterioles.
C. Decreased nerve activity to ventricular myocardium
D. Increased nerve activity to systemic peripheral veins
E. Increased nerve activity to cerebral arterioles
71. Which of the following best describes the effects of Increased sympathetic activity to ventricular myocardium?
A. Positive inotropic and negative dromotropic
B. Negative inotropic and positive chronotropic
C. Positive chronotropic and negative lusitropic
D. Positive chronotropic and negative dromotropic
E. Positive inotropic and positive lusitropic
72. In a normal vasculature, which of the following best describes the mean aortic pressure (MAP)?
A. It is the time average of the pulsatile aortic blood flow
B. It Is equal to one half the sum of the systolic and diastolic pressures
C. For a fixed TPR is value Is inversely related to cardiac output
D. It’s value is similar in most large arteries
E. Is value is about twice that of the pulmonary artery mean pressure
11
Cardiovascular STUDY Questions for Dentistry and Optometry Courtesy of Dr. HN Mayrovitz
73. Which of the following has the greatest pulse pressure?
A. Ascending Aorta
B. Thoracic Aorta
C. Large veins
D. Left Ventricle
E. Right Ventricle
For the next question, consider the following data set that applies to a single arteriole shown in the figure.
Intravascular average pressure = 25 mmHg
Extravascular pressure = 5 mmHg
Upstream entrance pressure = 40 mmHg
Downstream exit pressure = 10 mmHg
Average blood flow entering (Q) = 1 ml/min
Pe
r
Pd
Pi
Q
Pu
74. What is the resistance of this arteriole in the units given?
A. 10
B. 15
C. 20
D. 25
E. 30
75. In comparing average shear rates in two different vessels, which vessel definitely has the lower shear rate?
A. The one that has the smaller blood flow
B. The one that has the larger diameter
C. The one that has the larger diameter and the larger average blood velocity
D. The one that has the larger diameter and smaller average blood velocity
E. The one that has the smaller diameter and larger average velocity
76. Across which vascular segment is the most blood pressure energy lost?
A. Elastic arteries
B. Muscular arteries
C. Arterioles
D. Capillaries
E. Large veins
For the next two questions refer to the adjacent
figure, which shows five hypothetical organs that lie
between the aorta and a central vein. Each organ’s
complete vascular bed is represented by a precapillary and post-capillary part with PC as the midcapillary pressure. Values in boxes are resistances in
pru. Initial mean aortic pressure (MAP) is 100 mmHg
and mean pressure in the vein is 0 mmHg. Flow in
the figure is the cardiac output (CO).
Aorta
100 mmHg
Flow
8
12
PC
Vein
12
PC
8
PC
10
PC
PC
2
2
6
4
4
1
2
3
4
5
0 mmHg
77. In which organ is capillary pressure equal to 20 mmHg?
A. 1
B. 2
C. 3
D. 4
E. 5
12
Cardiovascular STUDY Questions for Dentistry and Optometry Courtesy of Dr. HN Mayrovitz
78. A drug is given that has only one direct effect; it constricts arterioles only of organ 5.
The drug does not change CO or vein pressure. Which one of the following occurs as a result of the drug?
A. Perfusion pressure for all organs decreases by the same amount
B. Perfusion pressure decreases only for organ 5
C. Total peripheral resistance decreases
D. In organ 3, blood flow decreases
E. In organ 4, blood flow increases
79. The compliance of the aorta will definitely decrease if:
A. Its lumen and wall thickness both increase
B. Its elastin/collagen ratio and its lumen increase
C. Its lumen increases and its wall thickness decreases
D. Its lumen decreases and its wall thickness increases
E. The elastic modulus of its wall decreases
For the next question refer to the figure below that represents a ventricular muscle fast response action potential
(AP)
80. At or near point x:
A. K1 channel conductance is high
B. Fast Na channels begin to open
C. Fast Na channels begin to close
D. The P-wave of the EKG starts
E. ICA is greater than IK
x
y
81. Partially blocking myocardial potassium (IK) channels is most likely to:
A. shorten the duration of the absolute refractory period of fast response AP
B. prolong phase 2 of the fast response AP
C. shorten the EKG’s QT interval
D. slow the rate of rise of fast response phase 0 depolarization
E. cause a wider QRS complex
82. Which one of the following statements is true?
A. The EKG T-wave represents left ventricular depolarization
B. The EKG P-wave represents SA node depolarization
C. AP conduction speed is essentially independent of the AP amplitude
D. The LV epicardium normally starts to repolarize before the endocardium
E. AP conduction speed in the AV node increases with vagal stimulation
83. Maximum velocity of shortening (Vmax) of myocardial fibers is most dependent on:
A. Preload
B. Afterload
C. End diastolic pressure
D. Contractility
E. Ventricular wall thickness
13
Cardiovascular STUDY Questions for Dentistry and Optometry Courtesy of Dr. HN Mayrovitz
84. Which of the following is the most accurate indicator of myocardial afterload during ventricular contraction?
A. Ventricular pressure
B. Ventricular wall stress
C. Aortic systolic pressure
D. Aortic diastolic pressure
E. Mean aortic pressure
85. Which of the following will increase left ventricular myocardial contractility?
A. An increase in preload
B. An increase in afterload
C. An increase in calcium current during the AP plateau phase
D. A drug-induced reduction in the calcium pool
E. A drug induced shortening of the AP plateau phase
86. If the third heart sound were present, during which left ventricle interval would it be heard?
A. During isovolumic contraction
B. During isovolumic relaxation
C. During ejection
D. During diastolic filling
E. During atrial contraction
87. Which of the following definitely tends to decrease aortic pulse wave velocity?
A. An increase in aortic compliance
B. An increase in calcium deposition in the aortic wall
C. An increase in rate of ejection from the left ventricle
D. An increase in stroke volume
E. An increase in cardiac contractility
88. Figure 1 shows cardiac chamber and aortic pressures vs. time. Which point is closest in time to the start of the
nd
2 heart sound?
A. A
B. B
C. C
D. D
E. E
For the next 2 questions refer to Figure 2 that shows Mary’s P-V loop.
160
90. If Mary’s heart rate is 50 beats/minute, what is her cardiac output?
A. 3 liters/minute
B. 4 liters/minute
C. 5 liters/minute
D. 6 liters/minute
E. 9 liters/minute
Figure 2
100
LV Pressure (mmHg)
89. Her ejection fraction in % is:
A. 30
B. 50
C. 60
D. Greater than 60
E. Indeterminate from the data
90
60
30
0
60
90
120
LV Volume (ml)
14
Cardiovascular STUDY Questions for Dentistry and Optometry Courtesy of Dr. HN Mayrovitz
91. For the figure below, which segment of the pressure-volume loop corresponds to the time interval between
points 3-4?
E
F
G
H
120
LV Pressure (mmHg)
A.
B.
C.
D.
3
Aortic
2
2
100
1
80
G
60
E
40
4
Atrial
F
4
H
3
Ventricle
0
0
1
0.2
0.5 seconds
40
80
120
LV Volume (ml)
For the next question assume the following hypothetical data to be true:
Capillary osmotic pressure = 30 mmHg, Tissue osmotic pressure = 5 mmHg , Tissue hydrostatic pressure = 3 mmHg
92. What must the capillary intravascular pressure be to make the net driving force for filtration equal to zero?
A. 24 mmHg
B. 26 mmHg
C. 28 mmHg
D. 30 mmHg
E. 32 mmHg
93. If terminal arterioles supplying a capillary network are undergoing rhythmic vasomotion then:
A. Capillary pressure decreases during the arteriole’s dilation phase
B. Capillary pressure increases during the arteriole’s constriction phase
C. Capillary blood flow decreases during the arteriole’s dilation phase
D. Capillary blood flow increases during the arteriole’s constriction phase
E. Capillary filtration increases during the arteriole’s dilation phase
94. Data associated with a large diameter collapsible vein are as follows:
Upstream pressure = 25 mmHg, Downstream pressure = 5 mmHg, External pressure = 15 mmHg, Resistance = 1
For these conditions which of the following best describes the blood flow value (ml/min) in this vessel?
A. 05
B. 10
C. 15
D. 20
E. 25
95. Which one of the following statements is true?
A. Carotid sinus (CS) baroreceptor gain is greatest at about 120 mmHg
B. High levels of blood CO2 cause a carotid body induced hypotension
C. High levels of blood O2 cause a carotid body induced increase total peripheral resistance
D. CS baroreceptors are normally the most important controller of long term blood pressure
E. CS baroreceptor afferent nerve traffic decreases if CS pressure decreases
15
Cardiovascular STUDY Questions for Dentistry and Optometry Courtesy of Dr. HN Mayrovitz
96. Increased stretch of atrial low pressure baroreceptors causes an increase in which of the following?
A. Sympathetic impulses to the kidney
B. ADH release
C. ANP release
D. Angiotensin II levels
E. TPR
97. The process by which coronary blood flow changes in accordance with demand is called:
A. Functional Hyperemia
B. Reactive Hyperemia
C. Autoregulation
D. Myogenic Control
E. Myogenic Response
98. The process by which cerebral blood flow tends to be maintained despite changes in perfusion pressure is
called:
A. Functional Hyperemia
B. Reactive Hyperemia
C. Autoregulation
D. Myogenic Control
E. Myogenic Response
99. Blood pressures for 5 persons are shown below. Which has isolated systolic hypertension?
A.
A
140 mmHg
B.
B
139 mmHg
120 mmHg
C.
B and C
D.
A and D
90 mmHg
E.
E
80 mmHg
A
B
C
D
E
100. Which one of the following would NOT increase fluid filtration from capillary to tissue?
A. Increased capillary permeability (P)
B. Increased capillary surface area (S)
C. Increased capillary PS product
D. Increased capillary osmotic pressure
E. Increased capillary hydrostatic pressure
101. An increase in stroke volume that occurs at a fixed preload is most likely due to:
A. The Frank-Starling mechanism
B. An increase in myocardial contractility
C. An increase in afterload
D. An increase in heart rate
E. An increase in end diastolic volume
102. Rhythmic vasomotion of terminal arterioles cause which of the following effects on downstream capillaries?
A. Capillary pressure decreases during the arteriole dilation phase
B. Capillary pressure increases during the arteriole constriction phase
C. Capillary blood flow decreases during the arteriole dilation phase
D. Capillary filtration increases during the arteriole dilation phase
E. Capillary blood flow increases during the arteriole constriction phase
16
Cardiovascular STUDY Questions for Dentistry and Optometry Courtesy of Dr. HN Mayrovitz
103. With respect to high pressure baroreceptors, if blood pressure decreases which of the following also
decreases?
A. Afferent impulse rate from carotid sinus receptors
B. Efferent impulse rate to arterioles
C. Efferent impulse rate to myocardium
D. Efferent impulse rate to systemic veins
E. Both B and C
104. Rhythmic vasomotion of terminal arterioles cause which of the following effects on downstream capillaries?
A. Capillary pressure decreases during the arteriole dilation phase
B. Capillary pressure increases during the arteriole constriction phase
C. Capillary blood flow decreases during the arteriole dilation phase
D. Capillary filtration increases during the arteriole dilation phase
E. Capillary blood flow increases during the arteriole constriction phase
105. With respect to high pressure baroreceptors, if blood pressure decreases which of the following also
decreases?
A. Afferent impulse rate from carotid sinus receptors
B. Efferent impulse rate to arterioles
C. Efferent impulse rate to myocardium
D. Efferent impulse rate to systemic veins
E. Both B and C
For the next two questions refer to the figure (below right) that represents one organ's vascular bed with a total
organ blood flow of Q1. Assume that the organ's perfusion pressure
remains constant.
One organ’s
Vascular
Bed A
vascular
bed
106. If all arterioles constrict, which of the following occurs?
A. capillary pressure and Q1 increase
B. capillary pressure and Q1 decrease
C. capillary pressure increases but Q1 decreases
D. capillary pressure decreases but Q1 increases
Aorta
107. If all arterioles dilate, which of the following occurs?
A. Blood velocity in the capillaries decreases
B. Blood pressure in the capillaries decreases
C. Wall shear stress in capillaries decreases
D. Transmural pressure in capillaries increases
Flow
Q1
= CO
Vena Cava
Arteries
Veins
Arterioles
Flow
Q2
= VR
Venules
Vascular Bed B
Capillaries
108. Blood flow produced by the left ventricle each minute is:
A. Increased if ventricle contractility is increased
B. Increased if ventricle preload decreases
C. Called the stroke volume
D. About 90% of the venous return
109. According to the Frank-Starling Mechanism:
A. Cardiac contractility increases as end diastolic volume increases
B. Stroke volume increases as end diastolic volume increases
C. Cardiac contractility increases with increasing sympathetic excitation
D. Heart rate decreases with increasing parasympathetic excitation
17
Cardiovascular STUDY Questions for Dentistry and Optometry Courtesy of Dr. HN Mayrovitz
110. Neglecting reflexes, which of the following tends to decrease mean arterial pressure (MAP)?
A. An increase in blood volume
B. Vasodilation of systemic arterioles
C. An increase in cardiac output
D. An increase in total peripheral resistance
For the next two questions use some of the following data recorded from a patient Mary Jones:
Heart Rate
Stroke Volume
Arterial Systolic Pressure
Arterial Diastolic Pressure
End Diastolic Volume
50 beats/minute
100 ml
150 mmHg
80 mmHg
200 ml
111. Mary’s cardiac output in ml/min is:
A. 5000
B. 6000
C. 7000
D. 9000
112. Mary’s pulse pressure in mmHg is:
A. 50
B. 70
C. 90
D. 100
113. The plateau phase of a cardiac action potential (AP) results mainly from a balance between:
A. Inward Na and outward K currents
B. Inward Ca and outward K currents
C. Outward Ca and outward K currents
D. Outward Na and inward K currents
114. A slower rate of spontaneous depolarization of the SA node AP occurs if:
A. Inward funny Na current (If) increases
B. Inward transient Ca current (ICa-T) increases
C. Outward K current (IK) increases
D. Inward long lasting Ca current (ICa-L) increases
115. Left ventricular end diastolic pressure (LVEDP) is:
A. the best parameter for describing ventricular preload
B. inversely proportional to ventricular preload
C. inversely proportional to LV end diastolic volume
D. inversely proportional to end diastolic ventricular compliance
116. During which part of the EKG does the cardiac vulnerable period occur?
A. P-wave
B. T-wave
C. QRS complex
D. AV node
18
Cardiovascular STUDY Questions for Dentistry and Optometry Courtesy of Dr. HN Mayrovitz
117. Which EKG event is closest in time to atrial contraction?
A. P-wave
B. T-wave
C. QRS complex
D. Q-T interval
For the next three questions refer to the below figure that depicts a persons left ventricle (LV), left atrial (LA) and
aortic blood pressures. Note: there are five points (1-5) and
140 mmHg
the corresponding pressures of some of these are also
120 mmHg
labeled.
3
2
118. Which event occurs at or near point 3?
A. First heart sound
B. Aortic valve opens
C. Second heart sound
D. The start of isovolumic contraction
E. Mitral valve closes
90
mmHg
Aortic
Pressure
LV
Pressure
4
1
LA Pressure
10 mmHg
5
0 mmHg
119. At or near which point does the mitral valve open?
A. 1
B. 2
C. 3
D. 4
E. 5
120. This persons’s diastolic blood pressure is closest to:
A. 140 mmHg
B. 120 mmHg
C. Somewhere between 120 and 140 mmHg
D. 90 mmHg
121. An age related decrease in aortic compliance will most likely cause an increase in:
A. Stroke volume
B. Cardiac contractility
C. Systolic blood pressure
D. Ventricular ejection rate
122. A carotid baroreceptor reflex to a sudden increase in blood pressure is a reflex:
A. tachycardia
B. increase in stroke volume
C. increase in cardiac output
D. decrease in total peripheral resistance
123. Which of the following tends to cause edema?
A. An increase in the permeability of capillaries
B. An increase in the osmotic pressure in capillaries
C. An increase in the protein concentration in capillaries
D. An increase in the resistance of arterioles feeding capillaries
19
Cardiovascular STUDY Questions for Dentistry and Optometry Courtesy of Dr. HN Mayrovitz
124. Dysfunction of communicating vein valves of the leg venous system results in:
A. A reduced venous pressure in superficial veins during walking
B. An increased blood flow through deep veins during walking
C. An increased pressure in superficial veins during walking
D. A more efficient calf muscle pump action
125. A significant stenosis in the carotid artery results in an increase in the:
A. blood flow to the brain
B. perfusion pressure of the brain
C. blood velocity in the stenosis
D. blood pressure in brain capillaries
126. In case of a fall in arterial pressure, which local mechanism helps maintain brain blood flow?
A. Autoregulation
B. Active Hyperemia
C. Reactive Hyperemia
D. Myogenic Response
For the next 3 questions use the following data obtained from a patient Sam while he was sitting.
Heart Rate
Systolic Blood Pressure
Diastolic Blood Pressure
Stroke Volume
Central Venous Pressure
End Diastolic Volume
50 beats/minute
160 mmHg
70 mmHg
100 ml
10 mmHg
80 ml
130. What is Sam’s mean arterial pressure (MAP) in mmHg?
A. 80
B. 90
C. 100
D. 115
131. Sam’s blood pressure would be classed as:
A. normal
B. high normal
C. pre-hypertensive
D. isolated systolic hypertension
132. If Sam’s MAP is 110 mmHg, his total peripheral resistance (TPR) in mmHg/liter/minute is:
A. 5
B. 10
C. 15
D. 20
133. A change in stroke volume that occurs at a fixed preload can be explained by:
A. The Frank-Starling mechanism
B. A change in preload
C. A change in end diastolic volume
D. A change in contractility
E. All of the above
20
Cardiovascular STUDY Questions for Dentistry and Optometry Courtesy of Dr. HN Mayrovitz
134. An increase in which of the following would reduce the compliance of a blood vessel?
A. wall thickness to radius ratio
B. wall elastin to collagen ratio
C. blood flow in the vessel
D. blood velocity in the vessel
135. According to the modified form of Laplace’s Law, stress in a blood vessel wall depends:
A. Directly on wall thickness
B. Directly on the radius to wall thickness ratio
C. Directly on the elastic modulus of the wall
D. Inversely to the transmural pressure
136. An endothelial cell related process that would cause vasodilation is:
A. An increase in the release of nitric oxide
B. A decrease in sympathetic impulses to arterioles
C. An increase in the release of endothelin
D. An increase in circulating levels of epinephrine
137. Which of the following would cause arteriolar vasodilation?
A. An increase in blood levels of angiotensin II
B. An increase in blood levels of vasopressin
C. Epinephrine acting unopposed on arteriole C-receptors
D. Epinephrine acting unopposed on arteriole C2-receptors
138. Which of the following is a true statement about the capillary network?
A. It has moderate amounts of sympathetic innervation
B. Blood velocity is high because of the small diameter of capillaries
C. Its total cross-sectional area is large
D. Vascular smooth muscle of capillaries participate in the myogenic response
139. If blood pressure in the carotid sinus decreases, which of the following reflex events occurs?
A. Sympathetic impulses to arterioles decrease
B. Sympathetic impulses to the myocardium decrease
C. Heart rate and stroke volume decrease
D. Total peripheral resistance increases
140. If just venoatrial receptors are stretched due to increased volume, which reflex events occurs?
A. Heart rate increases
B. Heart rate and stroke volume both increase
C. Heart rate and blood pressure both decrease
D. Sympathetic impulses to the renal arterioles increases
141. Which of the following would tend to cause edema?
A. Arteriole vasoconstriction
B. A decrease in venous pressure
C. A decrease in protein content of blood
D. An increase in tissue pressure
142. A person with significant lower extremity venous valve dysfunction will likely have a reduced:
A. ambulatory venous pressure
B. likelihood for developing venous ulcers
C. venous refilling time
D. pressure in foot veins while standing still
21
Cardiovascular STUDY Questions for Dentistry and Optometry Courtesy of Dr. HN Mayrovitz
143. Mary is a breast cancer survivor who two years ago had her left breast and six axillary lymph
nodes removed. She now has developed significant swelling of her left arm but her right arm is
of normal size and has no other swelling.
Which of the following would NOT be a likely possibility to explain Mary's condition?
A.
B.
C.
D.
She has developed a blood clot in one of the veins draining her left arm
She has a tumor that is compressing the lymphatic vessels draining the left arm
She has lymphedema due to progressive failure of normal lymphatic function in the left arm
She has developed a generalized hypoproteinemia due to liver dysfunction
144. Increased right atrial stretch due to increased blood volume causes:
A. a reduction in renal blood flow
B. a reduction in urine output due to an increase in antidiuretic hormone (ADH)
C. an increase in antidiuretic hormone (ADH)
D. an increase in atrial natriuritic peptide (ANP)
E.
an increase in angiotensin II
145. Which of the following best describes the effect if all arterioles within a single organ vasodilate?
A. Organ blood flow and capillary pressure both increase
B. Organ resistance and capillary pressure both increase
C. Organ resistance increases and capillary pressure decreases
D. Organ blood flow increases but capillary pressure decreases
146. Which best describes the effect of generalized vasoconstriction of peripheral arterioles?
A. Total systemic resistance increases causing a decrease in mean arterial pressure
B. Total systemic resistance and mean arterial blood pressure both increase
C. Total systemic resistance increases causing a decrease in mean arterial pressure
D. Total systemic resistance decreases causing a decrease in mean arterial pressure
147. Under normal conditions, which of the following would increase stroke volume?
A. Increased preload
B. Increased afterload
C. Decreased contractility
D. Decrease end diastolic volume
E. Both (b) and (d)
148. Which of the following would increase arterial pulse pressure?
A. Increased aortic compliance
B. Increased stroke volume
C. Decreased cardiac contractility
D. Decreased sympathetic excitation of the myocardium
149. Which is a normal reflex effect triggered by a sudden increase in carotid sinus pressure?
A. An increase in heart rate
B. An increase in stroke volume
C. An increase in total systemic resistance
D. An increase in vagus efferent impulses to the heart
150. Which is a true statement regarding calcium current (ICA) in normal ventricular muscle cells?
A. It is activated late in phase 3
B. Its maximum value occurs during phase 0
C. An increase in its value will increase myocardial contractility
D. A decrease in its value would increase heart rate
22
Cardiovascular STUDY Questions for Dentistry and Optometry Courtesy of Dr. HN Mayrovitz
151. Which of the following best describes reactive hyperemia?
A. A transient increase in blood flow following an interval of flow deprivation
B. A transient decrease in arteriole diameter when transmural pressure increases
C. Maintenance of blood flow despite changes in perfusion pressure
D. Changes in blood flow caused by increased or decreased metabolic activity
152. Which of the following tends to cause capillary pressure to increase?
A. A decrease in postcapillary resistance
B. Vasoconstriction of terminal arterioles
C. An increase in venous pressure
D. Increased sympathetic stimulation of arterioles
E. Both (c) and (d)
153. Which best accounts for the increase in stroke volume when end diastolic volume increases?
A. A decrease in myocardial contractility
B. An increase in positive inotropy of cardiac muscle
C. The Frank-Starling mechanism
D. An increase in sympathetic impulses to the myocardium
154. Which initially occurs if a person is rapidly tilted from a supine to an upright position?
A. Blood volume in the right atria increases
B. Stroke volume increases
C. Blood pressure decreases
D. Central venous pressure increases
155. Which best explains the large blood pressure loss across the arteriole part of the vasculature?
A. Arterioles have the greatest amount of vascular smooth muscle
B. Individual arterioles have the largest resistance of all vessels
C. The parallel combination of all arterioles has the largest resistance
D. The arterioles have the smallest average diameter
E. All of the above
23
Cardiovascular STUDY Questions for Dentistry and Optometry Courtesy of Dr. HN Mayrovitz
156. Which change that affects the SA node would tend to reduce heart rate?
A. An increase in funny current (If)
B. An increase in calcium current (ICA)
C. A decrease in potassium conductance (gK)
D. An decrease in calcium conductance (gCA)
157. During a stethoscopic examination of a patient, you hear a loud murmur (bruit) over the left
carotid artery. All other vascular sites are normal. What best explains the murmur?
A. An abnormally decreased blood flow through the carotid artery
B. A significantly increased cardiac output
C. An increase in blood velocity through a reduced lumen in the carotid artery
D. An increase in carotid diameter that causes an increase in Reynold's Number
E. An increase in the blood pressure in the carotid artery
158. Which reflex response normally occurs if carotid sinus blood pressure is decreased?
A. Stroke volume increases and heart rate decreases
B. Total peripheral resistance decreases and heart rate increases
C. Heart rate decreases causing cardiac output to decrease
D. Heart rate and stroke volume both increase
E. Carotid nerve afferent impulse rate decreases
159. Which of the following best describes functional hyperemia?
A. Blood flow adjustments to match local tissue metabolic needs
B. Excess transient blood flow increase after a prior blood flow deprivation
C. Maintained blood flow despite changes in perfusion pressure
D. Vasoconstriction in response to an increase in transmural pressure
E. Vasodilation in response to an increase in transmural pressure
160. Which of the following would NOT increase cardiac contractility?
A. Increased sympathetic stimulation of myocardium
B. Increased heart rate
C. Increased end-diastolic volume
D. Increased circulating levels of norepinephrine
E. Increase circulating levels of epinephrine
161. Which of the following best describes potential cause(s) of lower extremity edema?
A. Decreased venous pressure
B. Venous outflow obstruction
C. Decreased venous volume
D. Arteriole vasoconstriction
E. Both c) and d)
162. A patient has severe stenoses in both carotid arteries at sites located on the heart side of the carotid sinus.
Which of the following is the most likely effect?
A. Transmural pressure within the carotid sinus will increase
B. Reflex sympathetic discharge to arterioles will decrease
C. Reflex responses will tend to increase mean arterial pressure
D. Reflex responses will tend to decrease heart rate
E. Reflex responses will tend to reduce overall total peripheral resistance
24
Cardiovascular STUDY Questions for Dentistry and Optometry Courtesy of Dr. HN Mayrovitz
163. Which of the following events would tend to decrease stroke volume?
A. Increased afterload
B. Increased preload
C. Increased end diastolic volume
D. Increased end diastolic pressure
164. Stimulation of parsympathetic nerves to the heart will produce which of the following events?
A. Increased AV node conduction delay
B. Increased heart rate
C. Increased contractility
D. Increased stroke volume
E. All of the above
165. What cardiac cycle phase has a closed aortic valve and a fall in ventricular pressure?
A. Ventricular isovolumic contraction
B. Rapid ventricular ejection
C. Rapid ventricular filling
D. Atrial systole
E. Ventricular isovolumic relaxation
166. Which of the following statements about the venous system is correct?
A. The compliance of the venous system is nearly independent of venous pressure
B. Sympathetic activation of peripheral veins decreases their blood volume
C. Venous valve dysfunction results in a decreased ankle venous pressure on standing
D. Compression of calf muscle veins reduces overall calf muscle blood flow while walking
E. All of the above are correct
For question 167 – 171 there are definitely more than one correct answer. Choose all that are correct.
167. Increased stretch of Low Pressure Receptors (LPR) results in which of the following?
A. Reduced sympathetic impulses to the kidney
B. Reduced ADH release
C. Reduced urine output
D. Reduced ANP release from atria
E. Reduced levels of circulating Angiotensin II
168. An increase in which of the following will directly or indirectly result in vasoconstriction?
A. Antidiuretic Hormone (ADH) also called Vasopressin
B. Atrial Natriuritic Peptide (ANP)
C. Angiotensin II
D. Angiotensin I
E. Renin
169. Based on the adjacent simplified diagram and your knowledge of function, increased
sympathetic impulses to the kidney causes which of the following to occur?
A. Vasoconstriction
B. Reduced renal blood flow
C. Reduced intrarenal (efferent arteriole) blood pressure
D. Increased renin release
E. Reduced urine output
Main
Sympathetic
25
Cardiovascular STUDY Questions for Dentistry and Optometry Courtesy of Dr. HN Mayrovitz
170. Which of the following occurs in response to a large blood loss?
A. Tachycardia due to the Bainbridge reflex
B. Increased renin release due to sympathetic activity on renal β1 receptors
C. Increased renin release due to reduced renal blood pressure
D. Reduced urine output due to elevated levels of aldosterone
E. Increased TPR due to reduced levels of ADH
171. Assume a large blood pressure drop occurs as a result of a severe hemorrhage.
Which of the following will likely occur due to carotid baroreceptor reflexes?
A. Bradycardia
B. Increased TPR
C. Decreased venous compliance
D. Increased stroke volume
E. Increased efferent sympathetic activity
172. As a consequence of the Frank-Starling mechanism, a decrease in preload will result in:
A. decrease in stroke volume
B. an increase in stroke work
C. an increase in contractility
D. a decrease in contractility
E. a an increase in peak isovolumic pressure
173. Which of the following is a normal feature of individual capillaries in the skin?
A. Low vascular resistance
B. A thin layer of vascular smooth muscle
C. Single file red cell movement
D. Discontinuous walls
E. Fenestrated walls
174. Mary experiences a sudden partial, but significant, blockage in both internal carotid arteries. Each blockage is
on the heart side
of the carotid sinus. Which of the following would be a near immediate consequence of baroreceptor action?
A. Her mean aortic pressure (MAP) decreases
B. Both MAP and heart rate (HR) increase
C. Total peripheral resistance (TPR) decreases
D. Both TPR and HR decrease
E. Both TPR and MAP decrease
175. Which one of the following is NOT true about the coronary circulation?
A. Oxygen extraction is usually high even under resting conditions
B. Blood supply to the endocardium depends mainly on perfusion during diastole
C. Autoregulation ends at a higher perfusion pressure for endocardium than for epicardium
D. Coronary venous outflow occurs mainly during diastole
E. Coronary blood flow is nearly linearly related to myocardial oxygen consumption
26