Question 1

Which of the following areas of the conduction system would produce spontaneous action potentials most frequently if the SA node were not functioning?

Accepted Answer

A)  AV bundle
B)  Purkinje fibers
C)  AV node
D)  bundle branch
E)  the pacemakerF) C) and D)
G) D) and E)

Question 2

The peripheral chemoreceptors that respond to oxygen levels of the blood and regulate heart activity are located in _______________.

Accepted Answer

A)   the left ventricle
B)   the infundibulum of the hypothalamus
C)   structures near the carotids and aortic arch
D)   the medulla oblongata
E)   the right ventricleF) D) and E)
G) B) and D)

Question 3

The relationship between preload and stroke volume is known as

Accepted Answer

A)  extrinsic regulation.
B)  cardiac reserve.
C)  Starling Law of the heart.
D)  minute volume.E) A) and B)
F) A) and C)

Question 4

The delivery of oxygen and nutrients to the tissues of the body is accomplished through ________ circulation.

Accepted Answer

A)  hepatic
B)  pulmonary
C)  peripheral
D)  systemicE) A) and B)
F) A) and C)

Question 5

The baroreceptor reflex would cause which of the following events to occur if the reflex was caused by an increase in blood pressure?

Accepted Answer

A)  increased parasympathetic stimulation of the heart
B)  increased heart rate
C)  increased cardiac output
D)  increased force of contraction
E)  increased sympathetic stimulation of the heartF) A) and D)
G) C) and D)

Question 6

Which of the following would result from a reduced function of the sodium channels in the SA node?

Accepted Answer

A)  depolarization would be delayed
B)  the heart rate would decrease
C)  repolarization would not occur
D)  a shortened plateau phase
E)  depolarization would be delayed and the heart rate would decreaseF) D) and E)
G) C) and D)

Question 7

What is the importance of the delay in the action potential in the AV node?

Accepted Answer

A)  It allows the action potential to reach both ventricles at the same time.
B)  It allows an action potential to reach the left atrium so both atria contract together.
C)  It allows an action potential to reach the left atrium so both atria contract together,before the ventricles contract.
D)  It allows time for the atria to be filled with blood.E) A) and D)
F) B) and C)

Question 8

When a pacemaker potential in the SA node reaches threshold,

Accepted Answer

A)  the permeability to K+ ions increases.
B)  many voltage-gated Ca2+ channels open.
C)  voltage-gated Ca2+ channels close.
D)  RMP has been restored.
E)  permeability of the cell does not change.F) A) and C)
G) C) and E)

Question 9

What is the foramen ovale?

Accepted Answer

A)  An opening between the right and left atria in the embryo and fetus.
B)  An opening between the right and left ventricles in the embryo and fetus.
C)  An oval hole in the pericardium in the embryo and fetus.
D)  An opening between the pulmonary trunk and aorta in the embryo and fetus.E) B) and C)
F) All of the above

Question 10

The spontaneous opening of sodium channels marks the beginning of ____ of a myocardial cell.

Accepted Answer

A)  depolarization
B)  repolarization
C)  hyperpolarization
D)  isopolarization
E)  afterpolarizationF) C) and E)
G) D) and E)

Question 11

Which of the following is a function of the heart skeleton?

Accepted Answer

A)  Provides electrical insulation between the atria and ventricles.
B)  Supplies support and reinforcement for the valves.
C)  Provides a rigid site for cardiac muscle attachment.
D)  All of the choices are functions of the heart skeleton.E) A) and B)
F) A) and C)

Question 12

The adult heart averages ___________ grams.

Accepted Answer

A)   100-200
B)   50-100
C)   250-300
D)   400-500E) C) and D)
F) All of the above

Question 13

The action potentials are slowed at the AV node to allow the

Accepted Answer

A)  ventricles to repolarize.
B)  ventricles to completely empty of blood.
C)  pacemaker to reset for the next beat.
D)  atria to complete their contraction.
E)  atria to begin their contraction.F) B) and E)
G) A) and D)

Question 14

In a physiology lab,the students designed an experiment to illustrate how the heart responds to changes in blood pressure.Everyone relaxed and then did a headstand.Which of the following observations are consistent with the change in the function of their hearts?

Accepted Answer

A)  increased heart rate
B)  decreased heart rate
C)  increased stroke volume
D)  decreased stroke volume
E)  both decreased heart rate and increased stroke volumeF) B) and D)
G) A) and B)

Question 15

Excess potassium ions in cardiac tissue cause

Accepted Answer

A)  an increased heart rate.
B)  a rapid repolarization of cardiac cells.
C)  a decrease in the frequency of action potentials in the conduction system.
D)  an increase in stroke volume.
E)  an increase in the frequency of action potentials.F) None of the above
G) C) and D)

Question 16

The long refractory period observed in cardiac muscle

Accepted Answer

A)  prolongs depolarization of the cardiac muscle.
B)  prevents tetanic contractions of the cardiac muscle.
C)  ensures that the heart has adequate time to contract.
D)  prevents the heart rate from slowing down.
E)  prevents an increase in heart rate.F) B) and D)
G) A) and E)

Question 17

In the cardiac cycle,

Accepted Answer

A)  the right atrium and the right ventricle contract simultaneously.
B)  the two atria relax while the two ventricles contract.
C)  the left atrium contracts before the right atrium.
D)  all four chambers of the heart contract at the same time.
E)  all four chambers of the heart are in systole at the same time.F) A) and B)
G) All of the above

Question 18

Cardiac muscle cells

Accepted Answer

A)  have smooth ER but no T tubules.
B)  form the heart valves.
C)  are maintained by an extensive capillary network.
D)  develop a significant oxygen debt during systole.
E)  do not contain actin and myosin like skeletal muscle cells.F) None of the above
G) B) and E)

Question 19

A knowledge of heart location would NOT be important for which of the following?

Accepted Answer

A)   Blood pressure readings
B)   Stethoscope positioning
C)   Electrocardiogram
D)   Cardiopulmonary resucitationE) A) and B)
F) B) and C)

Question 20

Aortic stenosis results from

Accepted Answer

A)  a hole in the interatrial septum.
B)  a weakening of heart muscle.
C)  a narrowed opening through the aortic valve.
D)  low oxygen levels.
E)  leakage from the AV valves.F) A) and E)
G) B) and E)

Exam 20: Cardiovascular System: the Heart

What is the importance of the delay in the action potential in the AV node?

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The adult heart averages ___________ grams.

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The action potentials are slowed at the AV node to allow the

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The baroreceptor reflex would cause which of the following events to occur if the reflex was caused by an increase in blood pressure?

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Which of the following is a function of the heart skeleton?

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The long refractory period observed in cardiac muscle

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A knowledge of heart location would NOT be important for which of the following?

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Which of the following areas of the conduction system would produce spontaneous action potentials most frequently if the SA node were not functioning?

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Aortic stenosis results from

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In the cardiac cycle,

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Excess potassium ions in cardiac tissue cause

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The spontaneous opening of sodium channels marks the beginning of ____ of a myocardial cell.

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The delivery of oxygen and nutrients to the tissues of the body is accomplished through ________ circulation.

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The relationship between preload and stroke volume is known as

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Cardiac muscle cells

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In a physiology lab,the students designed an experiment to illustrate how the heart responds to changes in blood pressure.Everyone relaxed and then did a headstand.Which of the following observations are consistent with the change in the function of their hearts?

Correct AnswerverifiedShow Answer

What is the foramen ovale?

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When a pacemaker potential in the SA node reaches threshold,

Correct AnswerverifiedShow Answer

Which of the following would result from a reduced function of the sodium channels in the SA node?

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The peripheral chemoreceptors that respond to oxygen levels of the blood and regulate heart activity are located in _______________.

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