$$SV = 140\ \text{mL} - 65\ \text{mL} = 75\ \text{mL}$$

$$CO = 70 \times 80 = 5600\ \text{mL/min} = 5.6\ \text{L/min}$$

Question 1

Which of the following best describes the flow of blood through the heart and lungs in the pulmonary circuit?

Accepted Answer

Right atrium → Right ventricle → Pulmonary arteries → Lungs → Pulmonary veins → Left atrium

Question 2

Which heart valve prevents backflow of blood from the left ventricle to the left atrium?

Accepted Answer

Mitral (bicuspid) valve

Question 3

A patient has an End Diastolic Volume (EDV) of 140 mL and an End Systolic Volume (ESV) of 65 mL. What is their stroke volume (SV)?

$$SV = EDV - ESV$$

Accepted Answer

$$SV = 140\ 	ext{mL} - 65\ 	ext{mL} = 75\ 	ext{mL}$$

Question 4

Which of the following statements about the pericardium is TRUE?

Accepted Answer

The serous pericardium has both a parietal and a visceral layer, with serous fluid between them.

Question 5

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

Accepted Answer

It must generate higher pressure to pump blood through the systemic circulation.

Question 6

Which event is responsible for the first heart sound ("lub") heard during auscultation?

Accepted Answer

Closure of the atrioventricular (AV) valves

Question 7

A blockage in the left anterior descending (LAD) artery is often called the "widow maker" because:

Accepted Answer

It supplies a large portion of the left ventricle, and blockage can cause fatal myocardial infarction.

Question 8

Which of the following is a unique feature of cardiac muscle cells compared to skeletal muscle cells?

Accepted Answer

Presence of intercalated discs with gap junctions and desmosomes

Question 9

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

Accepted Answer

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

Question 10

Which of the following is the correct formula for cardiac output (CO)?

Accepted Answer

$$CO = HR 	imes SV$$

Question 11

If a patient has a heart rate (HR) of 70 bpm and a stroke volume (SV) of 80 mL, what is their cardiac output (CO) in L/min?

$$CO = HR 	imes SV$$

Accepted Answer

$$CO = 70 	imes 80 = 5600\ 	ext{mL/min} = 5.6\ 	ext{L/min}$$

Question 12

Which of the following best describes the role of the sinoatrial (SA) node?

Accepted Answer

It acts as the main pacemaker, initiating the electrical impulse for each heartbeat.

Question 13

Which of the following would most likely increase stroke volume?

Accepted Answer

Increased venous return during exercise

Question 14

Which of the following is TRUE regarding the cardiac muscle action potential?

Accepted Answer

It has a plateau phase due to slow calcium channels, preventing tetany.

Question 15

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

Accepted Answer

They supply oxygenated blood to the myocardium.

Question 16

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

Accepted Answer

Myocardial infarction (heart attack)

Question 17

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

Accepted Answer

Increased heart rate and contractility

Question 18

Which of the following best describes the Frank-Starling Law of the heart?

Accepted Answer

Increased ventricular filling (preload) leads to increased force of contraction and stroke volume.

Question 19

Which of the following is the correct sequence of the cardiac conduction system?

Accepted Answer

SA node → AV node → AV bundle (Bundle of His) → Bundle branches → Purkinje fibers

The Heart: Structure, Function, and Physiology

Study Guide - Practice Questions