Question 1

Which of the following best describes the function of the atrioventricular (AV) valves in the heart?

Accepted Answer

They prevent backflow of blood from the ventricles into the atria during ventricular contraction.

Question 2

A patient presents with mitral valve prolapse. Which of the following is most likely to occur as a result?

Accepted Answer

Blood may regurgitate from the left ventricle into the left atrium during systole.

Question 3

Which structure is responsible for initiating the electrical impulse that triggers the cardiac cycle?

Accepted Answer

Sinoatrial (SA) node

Question 4

During which phase of the cardiac cycle does ventricular filling primarily occur?

Accepted Answer

Mid-late diastole

Question 5

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

Accepted Answer

$CO = HR 	imes SV$

Question 6

A patient has a stroke volume ($SV$) of 70 mL and a heart rate ($HR$) of 80 beats per minute. What is their cardiac output ($CO$)?

Accepted Answer

$CO = 5600\ \mathrm{mL/min}$

Question 7

Which of the following best explains why intercalated discs are essential for cardiac muscle function?

Accepted Answer

They allow rapid transmission of electrical impulses, enabling the heart to contract as a functional syncytium.

Question 8

Which of the following would most likely result from blockage of the left coronary artery?

Accepted Answer

Myocardial infarction affecting the left ventricle

Question 9

Which of the following is a positive chronotropic agent and what effect does it have on the heart?

Accepted Answer

Epinephrine; increases heart rate

Question 10

A patient is diagnosed with bradycardia. Which of the following best describes this condition?

Accepted Answer

Heart rate is abnormally slow, typically below 60 beats per minute.

Question 11

Which of the following best describes the role of the Purkinje fibers in the cardiac conduction system?

Accepted Answer

They rapidly conduct impulses to the ventricular myocardium, ensuring coordinated contraction.

Question 12

Which of the following disorders is characterized by the inability of the heart to pump sufficient blood to meet the body's needs?

Accepted Answer

Congestive heart failure

Question 13

Which phase of the cardiac cycle is associated with the highest ventricular pressure?

Accepted Answer

Ventricular ejection

Question 14

Which of the following is the correct pathway for blood flow through the heart and lungs?

Accepted Answer

Right atrium → right ventricle → pulmonary artery → lungs → pulmonary vein → left atrium → left ventricle → aorta

Question 15

Which of the following best describes the importance of the absolute refractory period in cardiac muscle cells?

Accepted Answer

It prevents tetanic contractions, ensuring rhythmic heartbeats.

Question 16

A patient with pulmonary congestion is most likely to have dysfunction in which part of the heart?

Accepted Answer

Left ventricle

Question 17

Which of the following is a correct formula for stroke volume ($SV$)?

Accepted Answer

$SV = EDV - ESV$

Question 18

Which of the following would most likely increase cardiac output ($CO$) in a healthy adult?

Accepted Answer

Increased sympathetic stimulation

Question 19

A patient is experiencing heart block. Which of the following best describes this condition?

Accepted Answer

Electrical impulses are delayed or blocked between the atria and ventricles.

Question 20

Which of the following is a negative inotropic agent and what effect does it have on the heart?

Accepted Answer

Beta-blockers; decrease contractility

Chapter 18: The Heart – Structure, Function, and Cardiac Physiology

Study Guide - Practice Questions