$$CO = 80 \times 70 = 5600\,mL/min$$

Question 1

Which of the following best describes the function of the fibrous pericardium?

Accepted Answer

It prevents overstretching, protects, and anchors the heart.

Question 2

During ventricular systole, which valves are open and which are closed?

Accepted Answer

Atrioventricular valves are closed; semilunar valves are open.

Question 3

Which structure is responsible for the spontaneous generation of action potentials in the heart?

Accepted Answer

Sinoatrial (SA) node

Question 4

What is the main function of gap junctions in cardiac muscle cells?

Accepted Answer

To allow the flow of ions and spread of action potentials between cells

Question 5

Which of the following equations correctly represents cardiac output?

Accepted Answer

$$CO = HR 	imes SV$$

Question 6

A patient has an end diastolic volume (EDV) of 130 mL and an end systolic volume (ESV) of 60 mL. What is their stroke volume (SV)?

Accepted Answer

$$SV = 130\,mL - 60\,mL = 70\,mL$$

Question 7

Which of the following best explains why the myocardium of the left ventricle is thicker than that of the right ventricle?

Accepted Answer

It pumps blood to the entire body, requiring greater force to overcome higher resistance.

Question 8

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

Accepted Answer

Anchoring the heart to the diaphragm

Question 9

Which event occurs immediately after the firing of the SA node during the cardiac cycle?

Accepted Answer

Atrial depolarization and contraction

Question 10

A patient’s heart rate is 80 beats/min and their stroke volume is 70 mL/beat. What is their cardiac output?

Accepted Answer

$$CO = 80 	imes 70 = 5600\,mL/min$$

Question 11

Which of the following best describes the role of the AV node in the cardiac conduction system?

Accepted Answer

It delays the action potential to allow atrial contraction to complete before ventricular contraction.

Question 12

Which of the following is a correct sequence of blood flow through the heart?

Accepted Answer

Right atrium → right ventricle → pulmonary artery → lungs

Question 13

Which of the following is true regarding the plateau phase of the cardiac muscle action potential?

Accepted Answer

It is due to the simultaneous influx of Ca2+ and efflux of K+.

Question 14

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

Accepted Answer

They prevent inversion of the AV valve cusps into the atria during ventricular contraction.

Question 15

Which of the following would most likely increase stroke volume?

Accepted Answer

Increased myocardial contractility

Question 16

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

Accepted Answer

Increased heart rate

Question 17

Which of the following is the correct formula for stroke volume?

Accepted Answer

$$SV = EDV - ESV$$

Question 18

Which of the following best explains why the heart can continue to beat outside the body for a short period?

Accepted Answer

It contains pacemaker cells that spontaneously generate action potentials.

Question 19

Which of the following is NOT a function of the coronary arteries?

Accepted Answer

Carrying deoxygenated blood to the lungs

Question 20

Which wave on the ECG corresponds to ventricular depolarization?

Accepted Answer

QRS complex

The Heart: Structure, Function, and Cardiac Cycle

Study Guide - Practice Questions