Question 1

Which structure in the intrinsic cardiac conduction system is primarily responsible for initiating the electrical impulse that sets the pace for the heart's rhythm?

Accepted Answer

Sinoatrial (SA) node

Question 2

If the sinoatrial (SA) node fails to function, which part of the conduction system is most likely to take over as the pacemaker of the heart?

Accepted Answer

Atrioventricular (AV) node

Question 3

Which feature of cardiac tissue allows for the rapid spread of action potentials through the heart?

Accepted Answer

Gap junctions

Question 4

During the cardiac conduction cycle, which of the following correctly describes the sequence of electrical signal propagation?

Accepted Answer

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

Question 5

Which of the following best describes the function of the AV node's slower conduction velocity?

Accepted Answer

It ensures that the ventricles have enough time to fill with blood before they contract.

Question 6

Which answer choice below correctly matches the cardiac conduction structure to where it’s found in the heart?

Accepted Answer

Sinoatrial node: left atrium

Question 7

A patient has a mutation that disrupts the function of gap junctions in cardiac muscle. Which of the following would most likely result?

Accepted Answer

Action potentials would not spread efficiently from cell to cell, leading to uncoordinated contractions.

Question 8

Which statement best describes intrinsic conduction of the heart?

Accepted Answer

Cells within the heart can initiate and transmit action potentials without nervous system input.

Question 9

Which structure or structures are most directly responsible for allowing contraction of the ventricles to begin at the apex of the heart rather than in the septum closer to the AV node?

Accepted Answer

Purkinje fibers

Question 10

The sympathetic nervous system increases heart rate by acting on which part(s) of the cardiac conduction system?

Accepted Answer

The SA node, AV node, and heart muscle

Question 11

If the vagus nerve (parasympathetic input) to the heart is severed, what would you expect to happen to the resting heart rate?

Accepted Answer

It would increase to approximately 100 bpm.

Question 12

Which of the following best explains why there are no gap junctions between cardiomyocytes of the atria and ventricles?

Accepted Answer

To prevent the spread of action potentials from atria to ventricles except through the AV node.

Question 13

A patient’s ECG shows a delay between atrial and ventricular contraction. Which part of the conduction system is most likely responsible for this delay?

Accepted Answer

Atrioventricular (AV) node

Question 14

Which of the following is the correct order of events in the cardiac conduction pathway?

Accepted Answer

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

Question 15

Which of the following equations best represents the relationship between heart rate (HR), stroke volume (SV), and cardiac output (CO)?

Accepted Answer

$CO = HR 	imes SV$

Question 16

A patient is experiencing bradycardia (slow heart rate). Which of the following could be a likely cause based on the cardiac conduction system?

Accepted Answer

Increased activity of the parasympathetic nervous system

Question 17

Which of the following best describes the function of pacemaker cells in the SA node?

Accepted Answer

They rhythmically generate action potentials.

Question 18

Which of the following is a direct effect of sympathetic nervous system activation on the heart?

Accepted Answer

Increased heart rate

Question 19

A patient has a blockage in the right bundle branch. Which of the following would most likely be affected?

Accepted Answer

Conduction of action potentials to the right ventricle

Question 20

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

Accepted Answer

The heart contains intrinsic pacemaker cells that generate action potentials independently.

Cardiac Conduction System: Anatomy & Physiology Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards