$$CO = 90 \times 70 = 6300\ \mathrm{mL/min}$$

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 a blockage in the right coronary artery. Which region of the heart is most likely to be affected first?

Accepted Answer

Right atrium and portions of both ventricles

Question 3

Which structure is responsible for initiating the electrical impulse that sets the pace of the heart?

Accepted Answer

Sinoatrial (SA) node

Question 4

During ventricular systole, which of the following events occurs?

Accepted Answer

Blood is ejected from the ventricles into the pulmonary trunk and aorta.

Question 5

Which equation correctly represents cardiac output ($$CO) in $$terms of heart rate ($$HR) $$and stroke volume ($$SV$$)?

Accepted Answer

$$CO = HR 	imes SV$$

Question 6

A patient’s ECG shows an absence of P waves and irregular QRS complexes. Which arrhythmia is most likely present?

Accepted Answer

Atrial fibrillation

Question 7

Which layer of the heart wall is composed primarily of cardiac muscle tissue and is responsible for the heart’s contractile function?

Accepted Answer

Myocardium

Question 8

If the end-diastolic volume ($$EDV) is 140 mL $$and the end-systolic volume ($$ESV) is 60 mL$$, what is the stroke volume ($$SV$$)?

Accepted Answer

$$SV = EDV - ESV = 80\ \mathrm{mL}$$

Question 9

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

Accepted Answer

The greater the stretch of cardiac muscle fibers during filling, the greater the force of contraction and stroke volume.

Question 10

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

Accepted Answer

It drains deoxygenated blood from the myocardium into the right atrium.

Question 11

Which of the following statements about cardiac muscle cells is TRUE?

Accepted Answer

They are connected by gap junctions and desmosomes, allowing rapid electrical conduction.

Question 12

A patient has a heart rate of 90 bpm and a stroke volume of 70 mL. What is their cardiac output ($$CO$$)?

Accepted Answer

$$CO = 90 	imes 70 = 6300\ \mathrm{mL/min}$$

Question 13

Which of the following best describes the role of the AV bundle (bundle of His) in cardiac conduction?

Accepted Answer

It is the only electrical connection between the atria and ventricles.

Question 14

Which of the following would most likely increase end-diastolic volume ($$EDV$$)?

Accepted Answer

Increased venous return

Question 15

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

Accepted Answer

Increased heart rate and force of contraction

Question 16

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

Accepted Answer

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

Question 17

Which of the following ECG components corresponds to ventricular depolarization?

Accepted Answer

QRS complex

Question 18

A patient with a stenotic aortic valve is likely to experience which of the following?

Accepted Answer

Reduced blood flow from the left ventricle into the aorta

Question 19

Which of the following is TRUE regarding the pericardium?

Accepted Answer

It consists of a fibrous layer and a serous layer, providing protection and reducing friction.

Comprehensive Study Notes: The Heart (Anatomy & Physiology)

Study Guide - Practice Questions