AnS 214 SI Multiple Choice Set 3
Week 10/5 - 10/9
The following multiple choice questions pertain to material covered in this week's lecture set. Answering the following
questions will aid your exam preparation. These questions are meant as a gauge of your content knowledge - use them to
pinpoint areas where you need more preparation.
Answers to last week's MC Set 2:
Contact me if you have any questions regarding this answer key.
1. C
6. B
11. E
2. E
7. D
12. E
3. B
8. C
13. B
4. E
9. A
14. A
5. C
10. E
15. C
16. D
17. A
18. A
19. A
20. D
21. E
22. C
23. E
24. A
25. E
1. Which is the correct path of blood through the heart?
A. vena cava, left atrium, tricuspid valve, left ventricle, pulmonary valve, right atrium, mitral valve, right
ventricle, aortic valve
B.right atrium, bicuspid valve, right ventricle, pulmonary valve, left atrium, mitral valve, left ventricle,aortic valve
C. vena cava, right atrium, tricuspid valve, right ventricle, aortic valve, left atrium, mitral valve, left ventricle,
pulmonary semilunar valve
D. right atrium, tricuspid valve, right ventricle, pulmonary valve, left atrium, mitral valve, left ventricle,
aortic valve
E.vena cava, left atrium, tricuspid valve, right ventricle, pulmonary valve, left atrium, mitral valve, right ventricle,
aortic valve
2. Which of the following is TRUE about the heart?
A. ventricles fill passively, without aortic contractions
B. cardiac cells can be mono or binucleated
C. the diagram of an action potential is identical for cardiac and skeletal muscle
D. cardiac muscle, like skeletal, is comprised of motor units and contractions are driven by direct nervous
stimulation
E. muscle cells rely primarily on anaerobic respiration
3. Ventricular filling
A. is accomplished exclusively by negative pressure created by the expanding ventricle
B. is preceded by the QRS wave
C. has both passive and active elements
D. is characterized by a constant volume, which is very difficult to alter
E. occurs during the QRS wave
4. Angina pectoris
A. is characterized by a full obstruction of the coronary vessels
B. results in fibrosis of the cardiac muscle
C. will increase cardiac output in an attempt to provide more blood to the cardiac muscle
D. is characterized by ischemia and myocardial stunning
E. generally painless, and goes unnoticed
5. A full obstruction of the coronary artery
A. is called myocardial infarction
B. is called angina pectoris
C. will result in temporary loss of cardiac muscle
D. can be resolved by artificially induced decrease in heart rate
E. causes reversible damage, ameliorated by gradual regrowth of cardiac muscle
6. Cardiac contractions
A. are spontaneous and rhythmic
B. exhibit automaticity
C. have a relatively short refractory period
D. a, b and c are all true
E. a and b are both true
7. Cardiac cells
A. unlike skeletal muscle, do not exhibit striations
B. are all self-excitable (universal automaticity)
C. are electrically coupled to each other through gap junctions
D. release large volumes of Ca ions into the intercellular fluid upon excitation
E. require direct nervous stimulation for contraction
8. Stimulation of a cardiac cell
A. is initiated by Na diffusion into the cell
B. is stimulated by ACh binding to Na and K channels
C. triggers the expulsion of Ca out of the cells
D. is accomplished by coordinated Na leakage across all tissue cells
E. is unnecessary, as the cell fires spontaneously, without preceding changes in membrane potential
9. An action potential on the cardiac membrane
A. will cause calcium to both enter the cell through voltage gated channels and trigger its release from the
SR
B. is stimulated by gradual Ca seepage into the cell
C. is followed by a long relative refractory period
D. is triggered by ACh release from the vagus nerve
E. is the result of temporal summation from the neighboring cell
10. Which of the following is FALSE concerning the role of Ca in the cell?
A. prolongs the absolute refractory period by counteracting the effects of Na movement during an action
potential
B. is released from the SR under both chemical and ligand stimulation
C. enters the cell through slow electrically gated channels on the cell membrane
D. has both voltage and ligand gated channels in the cell that regulate its movement
E. responsible for both a faster membrane depolarization and a longer absolute refractory period
11. Repolarization in cardiac muscle
A. occurs at a faster rate than in skeletal muscle
B. is determined by Na levels in the cell
C. results from the gradual inactivation of Ca channels
D. is slower than in skeletal due to slower opening of K channels
E. is preceded by a short (relative to skeletal) contractile phase
12. Signal transduction in cardiac muscle
A. travels at the same rate through all 4 chambers
B. is initiated at the bundle of His in a normally functional heart
C. is expedited by the presence of gap junctions between cells
D. radiates freely away from the SA node to stimulate all surrounding tissues
E. must begin at the SA node to generate enough cardiac output to sustain life
13. Which of the following is TRUE about EKGs?
A. It clearly displays the electrical changes that occur during both atrial and ventricular
depolarization/repolarization cycles
B. It can infallibly diagnose the cardiac health status of the subject
C. A normal EKG displays what is called atrioventricular rhythm.
D. It displays the composite of all the action potentials generated by cardiac cells during the course of a
contraction
E. Sinus rhythm is what occurs during with a non-functional AV node, and displays a heart rate of 75 bpm.
14. In a sedentary (non-athletic) adult, the absence of vagal inhibition
A. the heart would loose all stimulation and cardiac arrest would ensue
B. resting heart rate would increase to its intrinsic tachycardic rate of 100 bpm
C. the SA node would become non-functional, causing the AV node to take over contraction initiation
D. the cardiac would become overstimulated and enter ventricular fibrillation
E. no significant changes would be detected by the individual
15. Cardiac automaticity
A. is the ability possessed by all cardiac cells to initiate a contraction
B. is dependent on the indirect stimulation of the SA node by the vagus nerve
C. is a result of an unstable resting membrane potential due to the leakage of Ca ions into the cell
D. results from the slow influx of K ions through leaky channels on the cardiac membrane
E. is the result of permanent membrane permeability to sodium ions in self-excitable cell groups
16. The ejection fraction
A. is a function of cardiac output, divided by the end diastolic volume
B. is decreased by exercise and althlete's heart
C. will approach 90% in a diseased heart, due to leakage of blood back into atria
D. depends on both the pre-contractile filling of the ventricles and strength of ventricular contractility
E. increases with increasing end systolic volume
17. Cardiac output
A. is the volume of blood pumped by both ventricles per minute
B. is the product of the heart beats per minute and the amount of blood ejected by each ventricle per minue
C. will increase up to 20 times resting output during exercise
D. is the single most important factor influencing blood pressure
E. is about 3L /minute in non-athletic individuals
18. Stroke volume is influenced by
A. ventricular distension
B. preload
C. peripheral resistance
D. venous return
E. all of the above influence stroke volume
19. Heart rate is affected by
A. positive and negative ionotropic factors
B. cardiac centers within the pons
C. extrinsic innervation by sympathetic and parasympathetic nerves
D. hypertension
E. norepinephrine from the vagus nerve
20. The Frank-Starling law of the heart
A. is explained by the length-tension relationship of sarcomeres with the conclusion that cardiac fibers are shorterthan-optimal in length
B. states that an increase in cardiac output requires an in crease in heart rate and stroke volume
C. states that an increase in venous return has a positive effect on SV and CO
D. all of the above are correct
E. only a and c are correct
21. Stroke volume
A. is inversely proportional to Ca content
B. increases under the effects of thyroxine, glucagon and epinephrine
C. increases to combat effects of hypertension
D. decreases with a growing concentration of intracellular K ions
E. is set by the vagus nerve
22. Autonomic control of the cardiac muscle
A. allows conscious regulation of HR
B. is achieved by the involvement of acetylcholine and norepinephrine
C. includes vagal tone, which sets HR above sinus rhythm to ensure maximum oxygenation of tissues
D. is unnecessary due to the automaticity of cardiac cells
E. none of the above are correct
23. Which of the following is TRUE?
A. Ventricles undergo depolarization before atria.
B. Non-functional atria result in the cessation of ventricular filling and induce cardiac arrest
C. Increasing volume of ventricular filling will increase heart rate and cardiac output
D. Increasing ventricular contractile will decrease EDV
E. Increasing volume of atrial filling will increase heart rate and cardiac output
24. Exercise
A. increases heart rate by decreasing venous return
B. induces cardiac hypertrophy, which decreases contractility and increases heart rate
C. increases cardiac reserve
D. all of the above
E. none of the above
25. After this exam, you will
A. have a nervous break down
B. throw a party
C. burn your textbook
D. lock yourself in the garage and turn on the car engine
E. all of the above, in that order
Answers to this MC set 3:
1. D
6. E
2. B
7. C
3. C
8. A
4. D
9. A
5. A
10. A
11. C
12. C
13. D
14. B
15. E
16. D
17. B
18. E
19. C
20. E
21. B
22. B
23. E
24. C
25. B