When acetylcholine is released, it causes the heart rate to:
A) slow and atrioventricular conduction rates to slow.
B) increase and atrioventricular conduction rates to slow.
C) slow and atrioventricular conduction rates to increase.
D) increase and atrioventricular conduction rates to increase.

Question

Quizplus · Accepted Answer

Acetylcholine is released by the parasympathetic nervous system and causes the heart rate to slow down and the atrioventricular conduction rates to slow down as well. This is because acetylcholine acts on muscarinic receptors in the heart, which slow down the pacemaker cells in the sinoatrial node and decrease the conductivity of the atrioventricular node.

When Acetylcholine Is Released, It Causes the Heart Rate To