The effect of acetylcholine on the heart is to:
A) decrease the refractory period.
B) increase calcium influx.
C) increase the strength of myocardial contraction.
D) decrease the heart rate.

Question

Quizplus · Accepted Answer

Acetylcholine is a neurotransmitter that slows down the heart rate by inhibiting the activity of the Sinoatrial node (SA node), which is responsible for initiating the electrical impulses that regulate heart rate. This decrease in electrical activity leads to a decrease in heart rate. Therefore, the correct choice is D, which is "decrease the heart rate."

The Effect of Acetylcholine on the Heart Is To