1. 18
The Cardiovascular System: The Heart

2. The apex of the heart points _______.
superiorly toward the right shoulder
laterally toward the right hip
inferiorly toward the left hip
posteriorly toward the left shoulder
Answer: c. inferiorly toward the left hip
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3. The apex of the heart points _______.
superiorly toward the right shoulder
laterally toward the right hip
inferiorly toward the left hip
posteriorly toward the left shoulder
Answer: c. inferiorly toward the left hip
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4. What is the double-walled sac covering the heart termed?
Pericardium
Myocardium
Epicardium
Endocardium
Answer: a. Pericardium
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5. What is the double-walled sac covering the heart termed?
Pericardium
Myocardium
Epicardium
Endocardium
Answer: a. Pericardium
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6. Of the following layers of the heart wall, which consumes the most energy?
Epicardium
Myocardium
Endocardium
Visceral pericardium
Answer: b. Myocardium
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7. Of the following layers of the heart wall, which consumes the most energy?
Epicardium
Myocardium
Endocardium
Visceral pericardium
Answer: b. Myocardium
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8. Which of the following structures is an exception to the general principle surrounding blood vessel oxygenation levels?
Pulmonary artery
Aorta
Pulmonary veins
Both a and c
Answer: d. Both a and c
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9. Which of the following structures is an exception to the general principle surrounding blood vessel oxygenation levels?
Pulmonary artery
Aorta
Pulmonary veins
Both a and c
Answer: d. Both a and c
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10. Which of the following statements is true?
All arteries transport oxygen-rich blood.
The right side of the heart is the systemic circuit pump.
Equal volumes of blood are pumped to the pulmonary and systemic circuits at any moment.
The left side of the heart pumps blood to the lungs.
Answer: c. Equal volumes of blood are pumped to the pulmonary and systemic circuits at any moment.
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11. Which of the following statements is true?
All arteries transport oxygen-rich blood.
The right side of the heart is the systemic circuit pump.
Equal volumes of blood are pumped to the pulmonary and systemic circuits at any moment.
The left side of the heart pumps blood to the lungs.
Answer: c. Equal volumes of blood are pumped to the pulmonary and systemic circuits at any moment.
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12. What purpose does the coronary circuit serve?
None; it is a vestigial set of vessels.
It delivers 1/20 of the body's blood supply to the heart muscle itself.
It delivers blood to the anterior lung surface for gas exchange.
It feeds the anterior thoracic wall.
Answer: b. It delivers 1/20 of the body's blood supply to the heart muscle itself.
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13. What purpose does the coronary circuit serve?
None; it is a vestigial set of vessels.
It delivers 1/20 of the body's blood supply to the heart muscle itself.
It delivers blood to the anterior lung surface for gas exchange.
It feeds the anterior thoracic wall.
Answer: b. It delivers 1/20 of the body's blood supply to the heart muscle itself.
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14. A heart murmur would be detected when blood is heard flowing from the ________ to the ________ through the ________.
right atrium; right ventricle; tricuspid valve
right atrium; left atrium; tricuspid valve
left ventricle; left atrium; mitral valve
left atrium; left ventricle; mitral valve
Answer: c. left ventricle; left atrium; mitral valve
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15. A heart murmur would be detected when blood is heard flowing from the ________ to the ________ through the ________.
right atrium; right ventricle; tricuspid valve
right atrium; left atrium; tricuspid valve
left ventricle; left atrium; mitral valve
left atrium; left ventricle; mitral valve
Answer: c. left ventricle; left atrium; mitral valve
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16. The presence of intercalated discs between adjacent cardiac muscle cells causes the heart to behave as a _______.
single chamber
contractile myofibril
desmosome
functional syncytium
Answer: d. functional syncytium
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17. The presence of intercalated discs between adjacent cardiac muscle cells causes the heart to behave as a _______.
single chamber
contractile myofibril
desmosome
functional syncytium
Answer: d. functional syncytium
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18. Cardiac muscle cells have several similarities with skeletal muscle cells. Which of the following is not a similarity?
The cells are each innervated by a nerve ending.
The cells store calcium ions in the sarcoplasmic reticulum.
The cells contain sarcomeres.
The cells become depolarized when sodium ions enter the cytoplasm.
Answer: a. The cells are each innervated by a nerve ending.
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19. Cardiac muscle cells have several similarities with skeletal muscle cells. Which of the following is not a similarity?
The cells are each innervated by a nerve ending.
The cells store calcium ions in the sarcoplasmic reticulum.
The cells contain sarcomeres.
The cells become depolarized when sodium ions enter the cytoplasm.
Answer: a. The cells are each innervated by a nerve ending.
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20. The stimulus for the heart's rhythmic contractions comes from _________.
intercalated discs
acetylcholine
a neuromuscular junction
a pacemaker potential
Answer: d. a pacemaker potential
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21. The stimulus for the heart's rhythmic contractions comes from _________.
intercalated discs
acetylcholine
a neuromuscular junction
a pacemaker potential
Answer: d. a pacemaker potential
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22. In a normal heart, which of the following structures is responsible for setting the heart's pace?
Sinoatrial node
Atrioventricular node
Atrioventricular bundle
Subendocardial conducting network
Answer: a. Sinoatrial node
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23. In a normal heart, which of the following structures is responsible for setting the heart's pace?
Sinoatrial node
Atrioventricular node
Atrioventricular bundle
Subendocardial conducting network
Answer: a. Sinoatrial node
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24. Predict the nature of an ECG recording when the atrioventricular node becomes the pacemaker.
There would continue to be a normal sinus rhythm.
The P wave would be much larger than normal.
The rhythm would be slower.
The T wave would be much smaller than normal.
Answer: c. The rhythm would be slower.
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25. Predict the nature of an ECG recording when the atrioventricular node becomes the pacemaker.
There would continue to be a normal sinus rhythm.
The P wave would be much larger than normal.
The rhythm would be slower.
The T wave would be much smaller than normal.
Answer: c. The rhythm would be slower.
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26. The input to the heart from the cardioinhibitory center primarily affects the ___________.
sinoatrial node and atrioventricular node
subendocardial conducting network
the cardiac contractile fibers
atrioventricular bundle
Answer: a. sinoatrial node and atrioventricular node
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27. The input to the heart from the cardioinhibitory center primarily affects the ___________.
sinoatrial node and atrioventricular node
subendocardial conducting network
the cardiac contractile fibers
atrioventricular bundle
Answer: a. sinoatrial node and atrioventricular node
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28. The "lub-dup" heart sounds are produced by _______.
the walls of the atria and ventricles slapping together during a contraction
the blood hitting the walls of the ventricles and arteries, respectively
the closing of the atrioventricular valves ("lub") and the closing of the semilunar valves ("dup")
the closing of the semilunar valves ("lub") and the closing of the atrioventricular valves ("dup")
Answer: c. the closing of the atrioventricular valves ("lub") and the closing of the semilunar valves ("dup")
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29. The "lub-dup" heart sounds are produced by _______.
the walls of the atria and ventricles slapping together during a contraction
the blood hitting the walls of the ventricles and arteries, respectively
the closing of the atrioventricular valves ("lub") and the closing of the semilunar valves ("dup")
the closing of the semilunar valves ("lub") and the closing of the atrioventricular valves ("dup")
Answer: c. the closing of the atrioventricular valves ("lub") and the closing of the semilunar valves ("dup")
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30. Atrial systole occurs _______ the firing of the sinoatrial node.
before
after
simultaneously with
alternately with
Answer: b. after
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31. Atrial systole occurs _______ the firing of the sinoatrial node.
before
after
simultaneously with
alternately with
Answer: b. after
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32. The majority (80%) of ventricular filling occurs ________.
during late ventricular diastole
passively through blood flow alone
with atrial systole
both a and b
Answer: d. both a and b
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33. The majority (80%) of ventricular filling occurs ________.
during late ventricular diastole
passively through blood flow alone
with atrial systole
both a and b
Answer: d. both a and b
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34. In terms of blood flow, why is it important that atrial diastole occurs just as ventricular systole begins?
The AV valves would remain open if the atria were still contracting.
The atria need that time to fill with blood in preparation for ventricular filling.
Ventricular systole pulls the remaining 20% of blood volume from the atria.
Blood would flow too fast otherwise.
Answer: b. The atria need that time to fill in preparation for ventricular filling.
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35. In terms of blood flow, why is it important that atrial diastole occurs just as ventricular systole begins?
The AV valves would remain open if the atria were still contracting.
The atria need that time to fill with blood in preparation for ventricular filling.
Ventricular systole pulls the remaining 20% of blood volume from the atria.
Blood would flow too fast otherwise.
Answer: b. The atria need that time to fill in preparation for ventricular filling.
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36. Cardiac output is determined by _______.
heart rate
stroke volume
cardiac reserve
both a and b
Answer: d. both a and b
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37. Cardiac output is determined by _______.
heart rate
stroke volume
cardiac reserve
both a and b
Answer: d. both a and b
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38. Your heart seems to "pound" after you hear a sudden, loud noise
Your heart seems to "pound" after you hear a sudden, loud noise. This increased contractility is _______.
because vagal nerve impulses arrive faster at the heart
because when a gasp of surprise is emitted, the Frank-Starling law of the heart is evident
due to norepinephrine causing threshold to be reached more quickly
because acetylcholine release is inhibited
Answer: c. due to norepinephrine causing threshold to be reached more quickly
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39. Your heart seems to "pound" after you hear a sudden, loud noise
Your heart seems to "pound" after you hear a sudden, loud noise. This increased contractility is _______.
because vagal nerve impulses arrive faster at the heart
because when a gasp of surprise is emitted, the Frank-Starling law of the heart is evident
due to norepinephrine causing threshold to be reached more quickly
because acetylcholine release is inhibited
Answer: c. due to norepinephrine causing threshold to be reached more quickly
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40. Why is high blood pressure damaging to the heart?
With high blood pressure, the blood is more viscous and harder to pump.
The heart rate slows down to dangerously low levels if blood pressure is too high.
Due to increased afterload, the left ventricle must contract more forcefully to expel the same amount of blood.
Sodium concentration increases during high blood pressure and is toxic to the myocardium.
Answer: c. Due to increased afterload, the left ventricle must contract more forcefully to expel the same amount of blood.
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41. Why is high blood pressure damaging to the heart?
With high blood pressure, the blood is more viscous and harder to pump.
The heart rate slows down to dangerously low levels if blood pressure is too high.
Due to increased afterload, the left ventricle must contract more forcefully to expel the same amount of blood.
Sodium concentration increases during high blood pressure and is toxic to the myocardium.
Answer: c. Due to increased afterload, the left ventricle must contract more forcefully to expel the same amount of blood.
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