Norepinephrine is considered a positive chronotropic agent because it causes
A. less calcium to enter heart cells, which leads to lower risk of heart attack.
B. more forceful contractions during each heart rate.
C. an increase in the firing rate of SA node cells.
D. thyroid hormone to have a steadying effect on heart activity.
E. heart cell membrane potentials to become more positive during action potentials.
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Question 2) Which of the following is not one of the three main factors influencing stroke volume?
A. Afterload
B. Chronotropic agents
C. Inotropic agents
D. Venous return
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Question 3) According to the Frank-Starling law
the more calcium available to the heart cell, the more forcefully it will contract.
B. as the volume of blood entering the heart increases, ventricular contractions become more forceful.
C.
the faster the heart rate, the larger the stroke volume.
D.
the greater the resistance from the arteries, the higher the blood pressure.
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Question 4) Cardiac reserve is greater in a nonathletic individual than in a highly trained athlete.
Indicate whether this statement is true or false.
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Question 5) The resistance in arteries to the ejection of blood by the heart is known as _________.
Fill in the blank with correct word.
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Question 6) A chemical that alters heart rate is known as a(n) __________ agent.
Fill in the blank with correct word.
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Question 7) What would you expect a cardiologist to recommend if there was substantial occlusion to a patient's left coronary artery but not the right coronary artery?
A.
Because there are multiple alternate paths for blood delivery, the cardiologist would not intervene.
B.
Because this is a relatively small, unimportant artery, the cardiologist would not intervene.
C.
Because this is an important artery, and alternate vascular paths are inadequate, the cardiologist would treat the condition.
D.
Because occlusions require blood to be moved under greater pressure, the cardiologist would prescribe drugs to raise blood pressure.
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Question 8) Large doses of certain stimulants can lead to dangerous increases in heart rates. Such a stimulant is a
A. positive chronotropic agent.
B. negative chronotropic agent.
C. positive inotropic agent.
D. negative inotropic agent.
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Question 9) Cardiac reserve is
A. the potential increase in stroke volume someone would show if they engaged in athletic training.
B. the increase in cardiac output an individual is capable of demonstrating during vigorous exercise.
C. the amount of blood left in the heart after the ventricle has contracted during cardiac cycles at rest.
D. the blood that the heart uses to nourish its cardiac muscle and does not put into general circulation.
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Question 10) Cardiac output is usually expressed in
A. beats per minute.
B. mL per beat.
C. mm Hg.
D. liters per minute.
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