A thrombus in the pulmonary trunk would interfere with blood:
1. being distributed to the systemic circulation.
2. picking up oxygen in the lungs.
3. getting into the right atrium.
4. leaving the left ventricle.
What separates the atria from the ventricles so that the atrial impulse does not spill onto the ventricles?
1. | fibrous skeleton | 2. | AV bundle |
3. | visceral pericardium | 4. | Purkinje fibers |
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If the atrioventricular node is damaged:
1. SA node would not develop action potential
2. atria will fail to contract
3. the impulse will not reach AV node
4. the impulse will not reach ventricles
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The SA node is the normal pacemaker of the human heart because its cells
1. spontaneously generate electrical signals about 70 to 80 times per minute.
2. are located in the interventricular septum.
3. generate electrical signals only when stimulated by sympathetic fibers.
4. are not in contact with other cells of the heart.
If the SA node is not functional in a human being, his ECG would not show:
1. P wave
2. QRS complex
3. ST segment
4. T wave
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What causes the opening of tricuspid and bicuspid valves?
1. Atrial pressure greater than pressure in the ventricles.
2. Ventricular pressure greater than pressure in the arteries.
3. Arterial pressure greater than pressure in the ventricles.
4. Ventricular pressure greater than pressure in the atria.
What happens during the isovolumetric relaxation of the cardiac cycle?
1. the atria contract and pump blood into the ventricles.
2. the ventricles contract and pump blood into the blood vessels.
3. both atria and ventricles are relaxed.
4. the ventricles contract but ventricular pressure is lower than arterial. pressure
The semilunar valves close at the beginning of
1. | atrial systole | 2. | atrial diastole |
3. | ventricular systole | 4. | ventricular diastole |
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How would the blood pumped per minute by the left ventricle compare with that pumped by the right ventricle?
1. normally greater than that of the right ventricle.
2. probably lower than the right ventricle if the person has systemic edema.
3. probably lower than the right ventricle if the person has pulmonary edema.
4. probably higher than the right ventricle if the person has pulmonary edema.
Under normal physiological conditions a higher cardiac output can be achieved by a higher:
1. extracellular concentration
2. blood pressure in the systemic circulation
3. venous return
4. parasympathetic tone