Question 1

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

Accepted Answer

Myocardium

Question 2

A patient is diagnosed with mitral valve insufficiency. Which of the following best describes the consequence of this disorder?

Accepted Answer

Blood flows backward from the left ventricle into the left atrium during ventricular contraction.

Question 3

Which of the following best describes the function of the pericardial fluid?

Accepted Answer

It lubricates the heart to reduce friction during contractions.

Question 4

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

Accepted Answer

SA node → AV node → AV bundle → Bundle branches → Purkinje fibers

Question 5

During which phase of the cardiac cycle are all heart valves closed and the ventricles are contracting but not yet ejecting blood?

Accepted Answer

Isovolumetric contraction

Question 6

Which of the following best explains why the plateau phase in the cardiac contractile cell action potential is important?

Accepted Answer

It prevents tetanus by prolonging the refractory period.

Question 7

A patient presents with a heart rate of 45 beats per minute. Which term best describes this condition?

Accepted Answer

Bradycardia

Question 8

Which of the following best describes the role of the SA node in the heart?

Accepted Answer

It acts as the pacemaker, initiating each heartbeat.

Question 9

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

Accepted Answer

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

Question 10

Which of the following ECG intervals is used to determine heart rate?

Accepted Answer

R-R interval

Question 11

A patient with coronary artery disease is at risk for which of the following complications due to decreased blood flow to the myocardium?

Accepted Answer

Myocardial infarction

Question 12

Which of the following best describes the effect of sympathetic nervous system stimulation on the heart?

Accepted Answer

Increases heart rate and contractility

Question 13

Which of the following is the main function of the atrioventricular (AV) valves?

Accepted Answer

Prevent backflow of blood from the ventricles into the atria during ventricular contraction

Question 14

Which of the following best explains why cardiac muscle cells are described as a functional syncytium?

Accepted Answer

They are connected by intercalated discs, allowing coordinated contraction.

Question 15

Which of the following best describes the mechanical event that produces the S1 heart sound?

Accepted Answer

Closure of the atrioventricular valves

Question 16

A patient’s ECG shows no distinct P waves and an irregularly irregular rhythm. Which condition is most likely present?

Accepted Answer

Atrial fibrillation

Question 17

Which of the following best describes the effect of acetylcholine on the heart?

Accepted Answer

Decreases heart rate and contractility

Question 18

Which of the following best explains why the heart can continue to beat even if all nervous connections are severed?

Accepted Answer

Cardiac muscle is intrinsic and autorhythmic due to pacemaker cells.

Question 19

Which of the following best describes the role of the Na+/K+ exchange pump during the cardiac action potential?

Accepted Answer

It restores the resting membrane potential after hyperpolarization.

Question 20

A patient is experiencing ventricular fibrillation. Which of the following best describes the electrical activity in the heart?

Accepted Answer

Disorganized electrical activity with no effective ventricular contraction

Study Guide: Anatomy and Physiology of the Heart (Cardiovascular System)

Study Guide - Practice Questions