The ion needed to initiate the release of acetylcholine into the synaptic cleft is
A) sodium.
B) potassium.
C) calcium.
D) chloride.
E) zinc.

Question

Quizplus · Accepted Answer

The ion needed to initiate the release of acetylcholine into the synaptic cleft is calcium. When an action potential reaches the axon terminal, it causes calcium channels to open and calcium ions to rush into the terminal. This influx of calcium triggers the release of acetylcholine into the synaptic cleft. Sodium and potassium ions are involved in generating the action potential itself, but not in the release of acetylcholine. Chloride and zinc ions are not involved in the release of acetylcholine.

The Ion Needed to Initiate the Release of Acetylcholine into the Synaptic