Multiple Choice
Which of the following correctly lists the main components of the cardiac conduction system in the order that an electrical impulse travels through the heart?
156
views
18. The Heart
Electrical Conduction System of the Heart
Multiple Choice
Which structure is the primary pacemaker of the heart under normal resting conditions?
A
Bundle of His (atrioventricular bundle)
B
Purkinje fibers
C
Atrioventricular (AV) node
D
Sinoatrial (SA) node
Verified step by step guidance1
Understand that the heart's rhythm is controlled by specialized cardiac muscle cells that generate electrical impulses, known as pacemakers.
Identify the main pacemaker structures: the Sinoatrial (SA) node, Atrioventricular (AV) node, Bundle of His, and Purkinje fibers.
Recognize that the primary pacemaker is the structure that initiates the heartbeat under normal resting conditions by generating the fastest and most regular impulses.
Recall that the SA node, located in the right atrium, has the highest intrinsic firing rate compared to the AV node, Bundle of His, and Purkinje fibers.
Conclude that because of its highest rate of depolarization and location, the SA node acts as the primary pacemaker, setting the pace for the heart's rhythm.
Related Videos
Related Practice
