Ch. 18 The Cardiovascular System: The Heart
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Problem 1
When the semilunar valves are open, which of the following are occurring? (1) coronary arteries fill (2) AV valves are closed (3) ventricles are in systole (4) ventricles are in diastole (5) blood enters aorta (6) blood enters pulmonary arteries (7) atria contract a. 2, 3, 5, 6, b. 1, 2, 3, 7, c. 1, 3, 5, 6, d. 2, 4, 5, 7.Problem 2
The portion of the intrinsic conduction system located in the superior interventricular septum is the a. AV node, b. SA node, c. AV bundle, d. subendocardial conducting network.Problem 3
An ECG provides information about a. cardiac output, b. movement of the excitation wave across the heart, c. coronary circulation, d. valve impairment.Problem 4
The sequence of contraction of the heart chambers is a. random, b. left chambers followed by right chambers, c. both atria followed by both ventricles, d. right atrium, right ventricle, left atrium, left ventricle.Problem 5
The fact that the left ventricular wall is thicker than the right reveals that it a. pumps a greater volume of blood, b. pumps blood against greater resistance, c. expands the thoracic cage, d. pumps blood through a smaller valve.Problem 6
The chordae tendineae a. the atrioventricular valves, b. prevent the AV valve flaps from everting, c. contract the papillary muscles, d. open the semilunar valves.Problem 7
In the heart, which of the following apply? (1) Action potentials are conducted from cell to cell across the myocardium via gap junctions, (2) the SA node sets the pace for the heart as a whole, (3) spontaneous depolarization of cardiac cells can occur in the absence of nerve stimulation, (4) cardiac muscle can continue to contract for long periods in the absence of oxygen. a. all of the above, b. 1, 3, 4, c. 1, 2, 3, d. 2, 3.Problem 8
Freshly oxygenated blood is first received by the a. atrium, b.atrium, c. right ventricle, d. left ventricle.Problem 10
The refractory period of cardiac muscle is much longer than that of skeletal muscle. Why is this a desirable functional property?Problem 11
Draw a normal ECG pattern. Label and explain the significance of its deflection waves.Problem 12
Define cardiac cycle, and follow the events of one cycle.Problem 13
What is cardiac output, and how is it calculated?Problem 14
As Cara worked at her dissection, she became frustrated that several of the structures she had to learn about had more than one common name. Provide another name for each of these structures: a. atrioventricular groove, b. tricuspid valve, c. bicuspid valve (give two synonyms), and d. atrioventricular bundle.Problem 15
The activity of the heart depends on intrinsic properties of cardiac muscle and on neural factors. Thus, a. vagus nerve stimulation of the heart reduces heart rate, b. sympathetic nerve stimulation of the heart decreases time available for ventricular filling, c. sympathetic stimulation of the heart increases its force of contraction, d. all of the above.Problem 16
Describe the pericardium and distinguish between the fibrous and the serous pericardia relative to histological structure and location.Problem 18
a. Describe how heart contraction and relaxation influence coronary blood flow. b. Name the major branches of the coronary arteries, and note the heart regions served by each.Problem 19
a. Name the elements of the intrinsic conduction system of the heart in order, beginning with the pacemaker. b. What is the important function of this conduction system?Problem 20
Discuss how the Frank-Starling law of the heart helps to explain the influence of venous return on stroke volume.Problem 21
You have been called upon to demonstrate the technique for listening to valve sounds. a. Explain where you would position your stethoscope to auscultate (1) the aortic valve of a patient with severe aortic valve insufficiency and (2) a stenotic mitral valve. b. During which period(s) would you hear these abnormal valve sounds most clearly? (During atrial diastole, ventricular systole, ventricular diastole, or atrial systole?) c. What cues would you use to differentiate between an insufficient and a stenotic valve?
