Once cells in the SA node reach threshold,
A)an action potential is triggered.
B)a heart attack occurs.
C)nothing happens until the AV node is innervated.
D)the heart stops beating.

Question

Quizplus · Accepted Answer

When the cells in the SA node reach threshold, an action potential is triggered, which leads to the contraction of the atria and the initiation of the heartbeat. The other options are incorrect as there is no mention of the AV node being necessary for the SA node to trigger an action potential and a heart attack or the heart stopping beating is not a direct result of the threshold being reached in the SA node.

Once Cells in the SA Node Reach Threshold