Question

question 6
acetylcholine release at a neuromuscular junction is stimulated by:
a arrival of the action potential
b acetylcholinesterase
c calcium
d sodium
e the neuromuscular signal potential

Explanation:

When an action potential arrives at the neuromuscular junction, it causes voltage - gated calcium channels in the presynaptic membrane to open. Calcium ions (\(Ca^{2+}\)) flow into the presynaptic neuron. This influx of calcium stimulates the release of acetylcholine (ACh) vesicles. Acetylcholinesterase breaks down acetylcholine, sodium is involved in action potential propagation (depolarization phase), and there is no such thing as a neuromuscular signal potential.

Answer:

C. calcium