Parasympathetic effects are localized and short-lived because
A) muscarinic receptors are deactivated by norepinephrine.
B) acetylcholine is inactivated at the synapse by acetylcholinesterase.
C) norepinephrine hyperpolarizes the postganglionic membrane.
D) norepinephrine is inactivated at the synapse by monoamine oxidase.
E) epinephrine blocks the muscarinic receptors.

Question

Quizplus · Accepted Answer

Parasympathetic effects are mediated by acetylcholine, which is quickly broken down by the enzyme acetylcholinesterase in the synapse. This ensures that the effects are localized and short-lived.

Parasympathetic Effects Are Localized and Short-Lived Because