Question 1

The cardiac cycle represents one heartbeat.

Accepted Answer

A) True 
 B)False

Question 2

Why do AV nodal cells NOT determine the heart rate under normal circumstances?

Accepted Answer

A)   They depolarize slower than all other conducting fibers.
B)   They slow conduction of the wave of excitation.
C)   They depolarize faster than all other conducting fibers.
D)   The AV node is connected to the SA node, but not to other conducting fibers in the heart.
E)   As depolarization initiated in the SA node reaches the AV node, it leaves the AV node in a refractory state.F) None of the above
G) All of the above

Question 3

Ischemia is a condition in which blood flow in a tissue is insufficient to keep up with metabolic demand.

Accepted Answer

A) True 
 B)False

Question 4

Describe the structures of the heart that are responsible for regulating the movement of blood from one chamber to the next.

Accepted Answer

The heart is a unique structure containi...

Question 5

The term autorhythmicity refers to the heart's ability to

Accepted Answer

A)   generate its own contractile cycle.
B)   intrinsically modify its contractility.
C)   conduct action potentials along the conduction pathway.
D)   originate its contraction neurogenically.
E)   act as a functional syncytium.F) B) and D)
G) None of the above

Question 6

What is the primary function of the AV and semilunar valves?

Accepted Answer

A)   to coordinate the autorhythmic movements of the heart
B)   to keep the right and left sides of the heart separated
C)   to control the speed at which blood enter and leaves the heart
D)   to permit blood to flow forward while preventing it from flowing backward
E)   The opening and closing of the valves creates the normal patterns of an EKG.F) All of the above
G) D) and E)

Question 7

In what phase is the cardiac cycle when the semilunar valves are open and AV valves are closed?

Accepted Answer

A)   atrial contraction
B)   ventricular filling
C)   isovolumetric contraction
D)   isovolumetric relaxation
E)   ventricular ejectionF) C) and D)
G) B) and D)

Question 8

Closure of the atrioventricular valve occurs when

Accepted Answer

A)   the atrium contracts.
B)   pressure inside the ventricle is greater than pressure inside the atrium.
C)   the valve contracts.
D)   pressure inside the ventricle is less than pressure inside the atrium.
E)   the papillary muscle contracts.F) B) and D)
G) A) and B)

Question 9

Which component of an ECG represents ventricular systole?

Accepted Answer

A)   P wave
B)   P -R interval
C)   T wave
D)   Q -T interval
E)   QRS complexF) A) and E)
G) A) and B)

Question 10

Which component of an ECG represents ventricular diastole?

Accepted Answer

A)   P -R interval
B)   T -Q segment
C)   Q -T interval
D)   QRS complex
E)   T waveF) A) and E)
G) A) and D)

Question 11

The repolarization of the ventricle is reflected in the

Accepted Answer

A)   P wave
B)   R -R interval
C)   P -Q interval
D)   T wave
E)   QRS complexF) A) and E)
G) A) and C)

Question 12

Which component of an ECG represents the AV nodal conduction time?

Accepted Answer

A)   P -R interval
B)   T wave
C)   QRS complex
D)   T -Q segment
E)   Q -T intervalF) None of the above
G) A) and D)

Question 13

The small increase in ventricular pressure observed late in diastole is caused by

Accepted Answer

A)   ventricular contraction.
B)   atrial relaxation.
C)   atrial contraction.
D)   blood moving into the atria from vena cava.
E)   ventricular relaxation.F) A) and B)
G) A) and C)

Question 14

During isovolumetric relaxation,

Accepted Answer

A)   the AV and semilunar valves are open and ventricular pressure is decreasing.
B)   the AV and semilunar valves are closed and ventricular pressure is decreasing.
C)   the AV valves are open, the semilunar valves are closed, and ventricular pressure is decreasing.
D)   the AV and semilunar valves are closed and ventricular pressure is increasing.
E)   the AV and semilunar valves are open and ventricular pressure is increasing.F) C) and E)
G) A) and C)

Question 15

Which of the following components of an ECG represents ventricular repolarization?

Accepted Answer

A)   P wave
B)   QRS complex
C)   T wave
D)   PQ interval
E)   TQ segmentF) B) and E)
G) A) and E)

Question 16

Blood returns to the left atrium via what blood vessels?

Accepted Answer

A)   iliac vein
B)   aorta
C)   coronary artery
D)   superior and inferior vena cavae
E)   pulmonary veinsF) B) and D)
G) None of the above

Question 17

Describe the changes in pressure and volume that occur within the left ventricle throughout the course of the cardiac cycle, starting at the beginning of diastole.

Accepted Answer

At the beginning of diastole, intraventr...

Question 18

If both the SA node and the AV node fail, what would be the expected outcome of impulse rate within the heart?

Accepted Answer

A)   The rate would be 30 -40 beats per minute due to the concentration of pacemaker cells in the Purkinje fibers.
B)   The sympathetic nervous system takes over and maintains normal heart rate.
C)   The individual would be in heart failure or have a myocardial infarction due to the lack of a beating heart.
D)   The vagus nerve takes over and maintains a normal heart rate.
E)   The heart is autorhythmic therefore it continually beats even after death because death is defined as a lack of brain waves.F) A) and B)
G) B) and E)

Question 19

The depolarization of the action potential in the pacemaker cells is driven by the rapid influx of _________ions through _________channels.

Accepted Answer

A)   potassium : T -type calcium
B)   potassium : funny
C)   sodium : T -type calcium
D)   sodium : funny
E)   calcium : L -type calciumF) A) and E)
G) A) and D)

Question 20

The volume of blood that is pumped by the heart every minute is determined by the equation

Accepted Answer

A)   EF = EDV -ESV.
B)   BP -PR × VL.
C)   T = PR/2.
D)   SV = EDV -ESV.
E)   CO = HR × SV.F) A) and B)
G) D) and E)

Exam 13: The Cardiovascular System: Cardiac Function

The volume of blood that is pumped by the heart every minute is determined by the equation

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Why do AV nodal cells NOT determine the heart rate under normal circumstances?

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Which of the following components of an ECG represents ventricular repolarization?

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During isovolumetric relaxation,

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Ischemia is a condition in which blood flow in a tissue is insufficient to keep up with metabolic demand.

Correct AnswerverifiedShow Answer

What is the primary function of the AV and semilunar valves?

Correct AnswerverifiedShow Answer

Which component of an ECG represents ventricular systole?

Correct AnswerverifiedShow Answer

If both the SA node and the AV node fail, what would be the expected outcome of impulse rate within the heart?

Correct AnswerverifiedShow Answer

The repolarization of the ventricle is reflected in the

Correct AnswerverifiedShow Answer

Blood returns to the left atrium via what blood vessels?

Correct AnswerverifiedShow Answer

Which component of an ECG represents the AV nodal conduction time?

Correct AnswerverifiedShow Answer

The depolarization of the action potential in the pacemaker cells is driven by the rapid influx of _________ions through _________channels.

Correct AnswerverifiedShow Answer

Closure of the atrioventricular valve occurs when

Correct AnswerverifiedShow Answer

The small increase in ventricular pressure observed late in diastole is caused by

Correct AnswerverifiedShow Answer

The cardiac cycle represents one heartbeat.

Correct AnswerverifiedShow Answer

Which component of an ECG represents ventricular diastole?

Correct AnswerverifiedShow Answer

The term autorhythmicity refers to the heart's ability to

Correct AnswerverifiedShow Answer

Describe the changes in pressure and volume that occur within the left ventricle throughout the course of the cardiac cycle, starting at the beginning of diastole.

Correct AnswerverifiedAt the beginning of diastole, intraventr...View AnswerShow Answer

In what phase is the cardiac cycle when the semilunar valves are open and AV valves are closed?

Correct AnswerverifiedShow Answer

Describe the structures of the heart that are responsible for regulating the movement of blood from one chamber to the next.

Correct AnswerverifiedThe heart is a unique structure containi...View AnswerShow Answer

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The depolarization of the action potential in the pacemaker cells is driven by the rapid influx of _ions through _channels.

Correct Answer
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At the beginning of diastole, intraventr...
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Correct Answer
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The heart is a unique structure containi...
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