Question 1

Which of the following best describes the functional significance of the interventricular septum in the heart?

Accepted Answer

It separates the left and right ventricles, preventing mixing of blood and providing a pathway for the bundle branches of the conduction system.

Question 2

A patient presents with a heart murmur due to regurgitation at the left atrioventricular valve. Which structure is most likely dysfunctional?

Accepted Answer

Mitral (bicuspid) valve

Question 3

Which of the following statements about the pericardium is correct?

Accepted Answer

The pericardial cavity is filled with pericardial fluid to reduce friction during heartbeats.

Question 4

Which vessel carries oxygenated blood from the lungs to the heart?

Accepted Answer

Pulmonary vein

Question 5

The Frank-Starling law of the heart can be mathematically expressed as:

Accepted Answer

$$SV \propto EDV$$

Question 6

Which of the following best explains why the left ventricular wall is thicker than the right?

Accepted Answer

The left ventricle must generate higher pressure to overcome greater resistance in the systemic circuit.

Question 7

Which of the following is the correct sequence of electrical conduction through the heart?

Accepted Answer

SA node → AV node → Bundle of His → Bundle branches → Purkinje fibers

Question 8

A blockage in the left anterior descending (LAD) artery would most directly affect which region of the heart?

Accepted Answer

Interventricular septum and anterior wall of the left ventricle

Question 9

Which of the following best describes the role of HCN channels in the SA node?

Accepted Answer

They open during hyperpolarization, allowing Na⁺ influx and generating the pacemaker potential.

Question 10

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

Accepted Answer

Increased force of ventricular contraction

Question 11

A patient with hyperkalemia is at risk for which of the following cardiac effects?

Accepted Answer

Decreased heart rate due to depolarization of the resting membrane potential

Question 12

Which of the following best explains why cardiac muscle is more fatigue-resistant than skeletal muscle?

Accepted Answer

Cardiac muscle contains a high density of mitochondria and myoglobin, supporting aerobic metabolism.

Question 13

Which of the following equations correctly calculates stroke volume (SV)?

Accepted Answer

$$SV = EDV - ESV$$

Question 14

Which of the following is the primary function of the fibrous skeleton of the heart?

Accepted Answer

To provide structural support, anchor cardiac myocytes, and electrically insulate the atria from the ventricles

Question 15

During the cardiac cycle, what event causes the first heart sound (S1, 'lupp')?

Accepted Answer

Closure of the atrioventricular (AV) valves after ventricular systole begins

Question 16

Which of the following best describes the role of gap junctions in cardiac muscle?

Accepted Answer

They allow direct cytoplasmic continuity for rapid ionic current flow, ensuring synchronous contraction.

Question 17

Which of the following is a direct result of calcium-induced calcium release (CICR) in cardiac myocytes?

Accepted Answer

Release of a large amount of Ca²⁺ from the sarcoplasmic reticulum, triggering contraction

Question 18

Which of the following best explains why the heart can continue to beat even when removed from the body and placed in a nutrient solution?

Accepted Answer

Cardiac muscle cells are autorhythmic and can spontaneously generate action potentials.

Question 19

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

Accepted Answer

Ischemia of the right atrium and right ventricle

Question 20

Which of the following best describes the effect of increased afterload on stroke volume?

Accepted Answer

Increased afterload decreases stroke volume.

The Heart: Structure, Function, and Cardiac Physiology

Study Guide - Practice Questions