The Structure Referred to as the Pacemaker of the Heart

Question

The structure referred to as the pacemaker of the heart is(are) the:
A)AV node.
B)SA node.
C)cardiac plexuses.
D)Both A and B are correct.

Accepted Answer

The SA (sinoatrial) node is known as the pacemaker of the heart because it generates the electrical impulses that initiate the heartbeat, setting the rhythm for the rest of the heart.