The heart's normal rhythm usually originates in the:
A)SA node.
B)atria.
C)AV node.
D)ventricle.

Question

Quizplus · Accepted Answer

The sinus or sinoatrial (SA) node is the natural pacemaker of the heart and is responsible for initiating the electrical impulses that drive the heart's normal rhythmic contractions. The other structures listed also play important roles in the conduction of these impulses and coordination of the heart's contractions, but the SA node is where the normal rhythm originates.

The Heart's Normal Rhythm Usually Originates in The