Chapter 9 Cardiac Physiology Questions

Question 1

Answer 1

1. F
2. F
3. F
4. F
5. T
6. F

Question 2

Answer 2

7. heart, blood vessels, blood
8. endothelium, myocardium, epicardium
9. intercalated discs, desmosomes, gap junctions
10. 80%
11. adenosine

Question 3

Answer 3

12. d

Question 4

Answer 4

13. e

Question 5

Answer 5

14.

• 1.e,
• 2.a,
• 3.d,
• 4.b,
• 5.f,
• 6.c

Question 6

Answer 6

15.

1. AV
2. systole
3. semilunar
4. diastole

Question 7

Answer 7

16.

• 1.b,
• 2.c,
• 3.a,
• 4.b,
• 5.a,
• 6.b,
• 7.b,
• 8.c,
• 9.c,
• 10.a,
• 11.b,
• 12.c

Question 8

Trace a drop of blood through one complete circuit of the circulatory system.

Answer 8

Question 9

Describe the location and function of each of the four heart valves. What keeps each of these valves from everting?

Answer 9

Question 10

Describe the structure and arrangement of cardiac muscle cells. What are the two specialized types of cardiac muscle cells?

Answer 10

Question 11

Discuss the ionic movements involved in the membrane clock mechanism and Calcium clock mechanism that are collectively responsible for the pacemaker potential.

Answer 11

Question 12

5. Why is the SA node the pacemaker of the heart?

Answer 12

Question 13

Describe the normal spread of cardiac excitation. What is the signficance of the AV nodal delay? Why is the ventricular conduction system important?

Answer 13

Question 14

7. Compare the changes in permeability, ionic movements, and membrane potential associated with an action potential in a nodal pacemaker cell with those in a myocardial contractile cell.

Answer 14

Question 15

8. Why is tetanus of cardiac muscle impossible? Why is this inability advantageous?

Answer 15

Question 16

9. What electrical event does each component of the ECG represent?

Answer 16

Question 17

Describe the mechanical events (that is, pressure changes, volume changes, valve activity, and heart sounds) of the cardiac cycle. Correlate the mechanical events of the cardiac cycle with the changes in electrical activity.

Answer 17

Question 18

Compare the defect, murmur associated with, and circulatory consequences of a stenotic and an insuficient valve.

Answer 18

Question 19

Distinguish among cardiac output, ejection fraction, and cardiac reserve.

Answer 19

Question 20

Discuss autonomic nervous system control of heart rate.

Answer 20

Question 21

Describe intrinsic and extrinsic control of stroke volume.

Answer 21

Question 22

What are the pathological changes and consequences of coronary artery disease?

Answer 22

Question 23

Discuss the sources, transport, and elimination of cholesterol in the body. Distinguish between “good” cholesterol and “bad” cholesterol.

Answer 23