Question 1

Which of the following best describes the sequence of electrical conduction in the heart?

Accepted Answer

SA node → AV node → Bundle of His → Right and left bundle branches → Purkinje fibers

Question 2

During which phase of the cardiac cycle does ventricular pressure exceed aortic pressure, resulting in the opening of the aortic valve?

Accepted Answer

Ventricular ejection

Question 3

Which of the following statements correctly compares the ionic basis of action potentials in pacemaker cells versus contractile cells of the heart?

Accepted Answer

Pacemaker cells depolarize due to calcium influx, while contractile cells depolarize due to sodium influx.

Question 4

Which event on an ECG corresponds most closely with ventricular depolarization?

Accepted Answer

QRS complex

Question 5

A patient has a 'leaky' left AV (mitral) valve. Which of the following is a likely consequence?

Accepted Answer

Increased left atrial volume during ventricular systole

Question 6

Which of the following best describes the Frank-Starling law of the heart?

Accepted Answer

The greater the end-diastolic volume, the greater the force of contraction.

Question 7

If the parasympathetic nervous system is stimulated, what is the expected effect on heart rate and cardiac output?

Accepted Answer

Heart rate decreases, cardiac output decreases

Question 8

Which of the following equations correctly defines cardiac output ($$CO$$)?

Accepted Answer

$$CO = HR 	imes SV$$

Question 9

During isovolumetric contraction, which of the following is true?

Accepted Answer

Both AV and semilunar valves are closed

Question 10

Which of the following would most likely increase stroke volume ($$SV$$)?

Accepted Answer

Increased sympathetic stimulation

Question 11

A thrombus (blood clot) in the right pulmonary artery would most directly affect which aspect of cardiac function?

Accepted Answer

Decrease left ventricular preload

Question 12

Which of the following best describes the source of calcium ($$Ca^{2+}) $$for contraction in cardiac muscle cells?

Accepted Answer

From both the sarcoplasmic reticulum and the extracellular fluid

Question 13

Which heart sound is associated with the closing of the semilunar valves?

Accepted Answer

Second heart sound (S2)

Question 14

Which of the following changes would most likely decrease cardiac output ($$CO$$)?

Accepted Answer

Increased parasympathetic activity

Question 15

Which of the following best defines mean arterial pressure ($$MAP$$)?

Accepted Answer

$$MAP = \frac{1}{3} (SBP - DBP) + DBP$$

Question 16

Which of the following is a direct effect of increased preload on the heart?

Accepted Answer

Increased end-diastolic volume

Question 17

Which phase of the cardiac cycle is characterized by rapid ventricular filling?

Accepted Answer

Early diastole

Question 18

If a patient has a 'leaky' right semilunar valve, what is the most likely effect?

Accepted Answer

Increased right ventricular end-diastolic volume

Question 19

Which of the following best describes the effect of increased afterload on stroke volume ($$SV$$)?

Accepted Answer

Increased afterload decreases stroke volume

Question 20

Which of the following is true regarding the relationship between the ECG and mechanical events of the heart?

Accepted Answer

The P wave precedes atrial contraction

Cardiac Physiology: Electrical and Mechanical Events, Cardiac Output, and Regulation

Study Guide - Practice Questions