Question 1

Atrial systole begins

Accepted Answer

A)  immediately before the P wave.
B)  immediately after the P wave.
C)  during the Q wave.
D)  during the S-T segment.
E)  immediately after the T wave.F) B) and D)
G) A) and B)

Question 2

The plateau in the action potential of cardiac muscle results from the action of

Accepted Answer

A)  Na+ inflow.
B)  K+ inflow.
C)  K+ outflow.
D)  fast Ca₂+ channels.
E)  slow Ca₂+ channels.F) B) and D)
G) B) and C)

Question 3

Papillary muscles prevent the AV valves from prolapsing (bulging) excessively into the atria when the
ventricles contract.

Accepted Answer

A) True 
 B)False

Question 4

The long plateau in the action potential observed in cardiocytes is probably related with staying longer in their cytosol.

Accepted Answer

A)  Na+
B)  K+
C)  Ca₂+
D)  Cl-
E)  Na+, K+, and Ca₂+F) A) and E)
G) A) and C)

Question 5

When the left ventricle contracts, the valve closes and the valve is pushed open.

Accepted Answer

A)  bicuspid; pulmonary
B)  tricuspid; pulmonary
C)  tricuspid; aortic
D)  mitral; aortic
E)  aortic; pulmonaryF) B) and D)
G) A) and B)

Question 6

Assume that the left ventricle of a child's heart has an EDV=90mL, and ESV=60mL, and a cardiac output of 2,400 mL/min.His SV and HR are

Accepted Answer

A)  SV=30 mL/beat, HR=80 bpm.
B)  SV=40 mL/beat, HR=60 bpm.
C)  SV=80 mL/beat, HR=30 bpm.
D)  SV=150 mL/beat, HR=16 bpm.
E)  SV=16 mL/beat, HR=150 bpm.F) B) and C)
G) B) and D)

Question 7

The Frank-Starling law of the heart states that stroke volume is proportional to

Accepted Answer

A)  the end-systolic volume.
B)  the end-diastolic volume.
C)  the afterload.
D)  the heart rate.
E)  contractility.F) B) and C)
G) None of the above

Question 8

Mitral valve stenosis causes blood to leak back into the when the ventricles contract.

Accepted Answer

A)  left atrium
B)  right atrium
C)  aorta
D)  pulmonary trunk
E)  pulmonary arteriesF) None of the above
G) B) and E)

Question 9

increase(s)  stroke volume.

Accepted Answer

A)  High arterial blood pressure
B)  Negative inotropic agents
C)  Increased venous return
D)  Increased afterload
E)  DehydrationF) A) and B)
G) D) and E)

Question 10

Blood in the heart chambers provides most of the myocardium's oxygen and nutrient needs.

Accepted Answer

A) True 
 B)False

Question 11

These are features of cardiac muscle fibers except

Accepted Answer

A)  they depend almost exclusively on aerobic respiration.
B)  they are rich in glycogen.
C)  they have huge mitochondria.
D)  they are very rich in myoglobin.
E)  they have about the same endurance as skeletal muscle fibers.F) B) and D)
G) B) and E)

Question 12

Hypercapnia and acidosis have positive chronotropic effects.

Accepted Answer

A) True 
 B)False

Question 13

carry oxygen-poor blood.

Accepted Answer

A)  Pulmonary veins and vena cavae
B)  Aorta and pulmonary veins
C)  Aorta and vena cavae
D)  Venae cavae and pulmonary arteries
E)  Pulmonary veins and pulmonary arteriesF) None of the above
G) All of the above

Question 14

The pulmonary circuit is supplied by both the right and the left sides of the heart.

Accepted Answer

A) True 
 B)False  False

Question 15

The pacemaker potential is a result of

Accepted Answer

A)  Na+ inflow.
B)  Na+ outflow.
C)  K+ inflow.
D)  K+ outflow.
E)  Ca₂+ inflow.F) B) and E)
G) A) and C)

Question 16

This figure shows the events of the cardiac cycle.What does "4" represent?

Accepted Answer

A)  aortic valve opening
B)  aortic valve closing
C)  AV valve opening
D)  AV valve closing
E)  both aortic and AV valves openingF) A) and D)
G) B) and E)

Question 17

Atrial hypertrophy would probably cause an enlarged P wave on an electrocardiogram.

Accepted Answer

A) True 
 B)False  True

Question 18

If the sinoatrial (SA)  is damaged, the heart will likely beat at

Accepted Answer

A)  less than 10 bpm.
B)  10 to 20 bpm.
C)  20 to 40 bpm.
D)  40 to 50 bpm.
E)  70 to 80 bpm.F) D) and E)
G) A) and E)

Question 19

Cardiac muscle shares this feature with skeletal muscle.

Accepted Answer

A)  cardiac muscle fibers have striations
B)  all cardiac muscle fibers depend on nervous stimulation
C)  cardiac muscle fibers communicate by electrical (gap)  junctions
D)  cardiac muscle fibers are joined end to end by intercalated discs
E)  some cardiac muscle fibers are autorhythmicF) D) and E)
G) A) and C) A

Question 20

This figure shows the events of the cardiac cycle.At 0.2 sec in the graph .

Accepted Answer

A)  the aortic valve is open
B)  the AV valve is open
C)  the ventricles have reached end-diastolic volume
D)  the ventricles are in the isovolumetric phase
E)  the ventricles are in systoleF) B) and D)
G) A) and C)

Exam 19: The Circulatory System: Heart

Atrial systole begins

Correct AnswerverifiedShow Answer

The plateau in the action potential of cardiac muscle results from the action of

Correct AnswerverifiedShow Answer

Papillary muscles prevent the AV valves from prolapsing (bulging) excessively into the atria when the ventricles contract.

Correct AnswerverifiedShow Answer

The long plateau in the action potential observed in cardiocytes is probably related with staying longer in their cytosol.

Correct AnswerverifiedShow Answer

When the left ventricle contracts, the valve closes and the valve is pushed open.

Correct AnswerverifiedShow Answer

Assume that the left ventricle of a child's heart has an EDV=90mL, and ESV=60mL, and a cardiac output of 2,400 mL/min.His SV and HR are

Correct AnswerverifiedShow Answer

The Frank-Starling law of the heart states that stroke volume is proportional to

Correct AnswerverifiedShow Answer

Mitral valve stenosis causes blood to leak back into the when the ventricles contract.

Correct AnswerverifiedShow Answer

increase(s) stroke volume.

Correct AnswerverifiedShow Answer

Blood in the heart chambers provides most of the myocardium's oxygen and nutrient needs.

Correct AnswerverifiedShow Answer

These are features of cardiac muscle fibers except

Correct AnswerverifiedShow Answer

Hypercapnia and acidosis have positive chronotropic effects.

Correct AnswerverifiedShow Answer

carry oxygen-poor blood.

Correct AnswerverifiedShow Answer

The pulmonary circuit is supplied by both the right and the left sides of the heart.

Correct AnswerverifiedFalse

The pacemaker potential is a result of

Correct AnswerverifiedShow Answer

This figure shows the events of the cardiac cycle.What does "4" represent?

Correct AnswerverifiedShow Answer

Atrial hypertrophy would probably cause an enlarged P wave on an electrocardiogram.

Correct AnswerverifiedTrue

If the sinoatrial (SA) is damaged, the heart will likely beat at

Correct AnswerverifiedShow Answer

Cardiac muscle shares this feature with skeletal muscle.

Correct AnswerverifiedA

This figure shows the events of the cardiac cycle.At 0.2 sec in the graph .

Correct AnswerverifiedShow Answer

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
False

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified
True

Correct Answer
verified

Correct Answer
verified
A

Correct Answer
verified