$$CO = 80 \times 70 = 5600\ \text{mL/min}$$

Question 1

Which of the following best describes the function of the chordae tendineae in the heart?

Accepted Answer

They prevent the atrioventricular (AV) valves from inverting into the atria during ventricular contraction.

Question 2

A patient presents with a very large QRS complex on their EKG. What is the most likely explanation for this finding?

Accepted Answer

Enlarged heart

Question 3

Which layer of the heart wall is responsible for the contractile force that pumps blood?

Accepted Answer

Myocardium

Question 4

During which phase of the cardiac cycle do the AV valves close, producing the 'lubb' sound?

Accepted Answer

Ventricular systole

Question 5

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

Accepted Answer

$$CO = HR 	imes SV$$

Question 6

A blockage in the left coronary artery would most directly affect which part of the heart?

Accepted Answer

Left ventricle

Question 7

Which structure is known as the heart's natural pacemaker?

Accepted Answer

Sinoatrial (SA) node

Question 8

If the P wave is missing or inverted on an EKG, what is the most likely cause?

Accepted Answer

SA node damage

Question 9

Which of the following best explains why the left ventricle has a thicker wall than the right ventricle?

Accepted Answer

It pumps blood to the entire body, requiring greater pressure.

Question 10

Which of the following is NOT a function of the pericardial fluid?

Accepted Answer

Delivering oxygen to the myocardium

Question 11

A patient has a heart rate of 80 beats per minute and a stroke volume of 70 mL per beat. What is their cardiac output?

Accepted Answer

$$CO = 80 	imes 70 = 5600\ 	ext{mL/min}$$

Question 12

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

Accepted Answer

Increased stroke volume

Question 13

Which of the following best describes the function of the coronary sinus?

Accepted Answer

It collects deoxygenated blood from the myocardium and empties into the right atrium.

Question 14

Which event occurs during the T wave of a normal EKG?

Accepted Answer

Ventricular repolarization

Question 15

Which of the following would most likely increase cardiac output during exercise?

Accepted Answer

Increased heart rate and increased stroke volume

Question 16

Which of the following is the correct sequence for the propagation of the cardiac action potential?

Accepted Answer

SA node → AV node → Bundle branches → Purkinje fibers

Question 17

Which of the following best explains why a heart murmur may be heard?

Accepted Answer

Regurgitation of blood through a faulty valve

Question 18

Which of the following factors would most likely increase afterload?

Accepted Answer

Increased arterial pressure

Question 19

Which of the following is a direct effect of sympathetic nervous system stimulation on the heart?

Accepted Answer

Increased heart rate

Question 20

Which of the following best describes the function of the semilunar valves?

Accepted Answer

They prevent backflow of blood into the ventricles after ventricular contraction.

Chapter 20: The Heart – Structure, Function, and Physiology

Study Guide - Practice Questions