Question

The normal physiologic function of the atrioventricular (AV) node is to ___________.

A. prevent the atria and ventricles from contracting simultanc ously.
B. depolarize the left and right atria.
C. repolarize the heart after systole.
D. set the basic electrical frythm of the heart by acting as the pacemaker.

Answer 1

The AV node's function is to delay the electrical impulse between the atria and ventricles, allowing coordinated contractions and proper blood flow within the heart. The correct option is A.

Step-by-step explanation:

The normal physiologic function of the atrioventricular (AV) node is to prevent the atria and ventricles from contracting simultaneously. This is critical for the heart's function because it ensures that the atria have time to fully empty their contents into the ventricles before the ventricles contract.

The AV node introduces a delay or pause in the electrical impulse, which is due in part to the small diameter of its cells and the less efficient conduction between nodal cells.

With extreme stimulation by the SA node, the AV node can transmit impulses at a maximal rate of 220 per minute, setting the typical maximum heart rate in a healthy young individual. The correct option is A.