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

Question 1

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

Accepted Answer

Myocardium

Question 2

A patient presents with pericarditis, an inflammation of the pericardium. Which of the following is a direct consequence of this condition?

Accepted Answer

Increased friction between the heart and surrounding tissues

Question 3

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

Accepted Answer

AV valves closed, semilunar valves open

Question 4

Which of the following best describes the function of the chordae tendineae and papillary muscles?

Accepted Answer

They prevent prolapse of the AV valves during ventricular contraction

Question 5

A red blood cell traveling from the right atrium to the left atrium must pass through which sequence of structures?

Accepted Answer

Tricuspid valve → right ventricle → pulmonary valve → pulmonary arteries → lungs → pulmonary veins

Question 6

Which formula correctly calculates cardiac output ($$CO$$)?

Accepted Answer

$$CO = SV 	imes HR$$

Question 7

If a patient’s heart rate is 80 beats per minute and their stroke volume is 70 mL per beat, what is their cardiac output?

Accepted Answer

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

Question 8

Which of the following statements about the absolute refractory period in cardiac muscle is correct?

Accepted Answer

It prevents tetanic contractions, ensuring rhythmic heartbeats

Question 9

Which component of the intrinsic conduction system acts as the heart’s natural pacemaker?

Accepted Answer

SA node

Question 10

A patient’s ECG shows an abnormal QRS complex. What does this most likely indicate?

Accepted Answer

Abnormal ventricular depolarization

Question 11

Which of the following would most likely increase heart rate?

Accepted Answer

Release of norepinephrine from the sympathetic nervous system

Question 12

Which property is unique to cardiac muscle cells compared to skeletal muscle cells?

Accepted Answer

Presence of intercalated discs

Question 13

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

Accepted Answer

The greater the stretch of cardiac muscle fibers, the greater the force of contraction

Question 14

Which of the following would decrease stroke volume?

Accepted Answer

Decreased contractility

Question 15

Which structure prevents backflow of blood from the right ventricle into the right atrium?

Accepted Answer

Tricuspid valve

Question 16

Which of the following is a function of the coronary arteries?

Accepted Answer

They supply oxygenated blood to the heart muscle

Question 17

Which event occurs during the second heart sound ($$S_2$$)?

Accepted Answer

Closure of semilunar valves

Question 18

Which of the following best describes the role of desmosomes in cardiac muscle?

Accepted Answer

They provide strong cell-cell adhesion during contraction

Question 19

Which phase of the cardiac cycle is characterized by all chambers being relaxed?

Accepted Answer

Quiescent period

Question 20

Which of the following would most likely result from a blockage in the coronary veins?

Accepted Answer

Impaired removal of deoxygenated blood from the myocardium

The Heart: Structure, Function, and Physiology – Study Notes

Study Guide - Practice Questions