The Effect of Acetylcholine Binding to Its Receptors in the Heart

Question

The effect of acetylcholine binding to its receptors in the heart is a heart rate
A)increase.
B)decrease.
C)unchanged.

Accepted Answer

Acetylcholine binds to muscarinic receptors in the heart, which leads to a decrease in heart rate by decreasing the rate of electrical impulses generated by the sinoatrial node (the pacemaker of the heart). This is part of the parasympathetic (rest and digest) nervous system response, which opposes the sympathetic (fight or flight) response that increases heart rate.