When an action potential arrives at the axon terminal, the voltage-gated calcium channels at the terminal
A) release calcium into the synaptic cleft.
B) release neurotransmitter into the synaptic cleft through active transport.
C) open, and the influx of calcium causes vesicle fusion with the presynaptic membrane.
D) cause further depolarization of the membrane at the motor end plate.
E) cause the membrane receptors to bind the neurotransmitter.

Question

Quizplus · Accepted Answer

When an action potential arrives at the axon terminal, the voltage-gated calcium channels open, allowing an influx of calcium. This causes vesicle fusion with the presynaptic membrane, resulting in the release of neurotransmitter into the synaptic cleft. Option A is partially correct but incomplete. Option B is incorrect because neurotransmitter release occurs through exocytosis, not active transport. Option D is specific to neuromuscular junctions and not universally applicable. Option E is incorrect because it implies that the receptors are already present, whereas receptor activation occurs after neurotransmitter release.

When an Action Potential Arrives at the Axon Terminal, the Voltage-Gated