Question

During the transmission of signals across a neuromuscular junction, which of the following happens first?

> Acetylcholine binds to a receptor protein on the motor end plate.
The sodium and potassium ion gates on the motor end plates open.
Synaptic vesicles release acetylcholine molecules.
Synaptic vesicles move toward the axon terminals.

Answer 1

@aaronq

Answer 2

i think it's "the sodium and potassium ion gates on the motor end plates open" but i dont remember with certainty.

i found the steps here http://www.me.umn.edu/~wkdurfee/projects/itasca/lectureNotes.pdf

Steps in neuromuscular transmission:
1) nerve action potential.
2) calcium entry into the presynaptic terminus.
3) release of Ach quanta.
4) diffusion of Ach across cleft.
5) combination of Ach with post-synaptic receptors and Ach breakdown via esterase.
6) opening of Na+/K+
channels (cation channels).
7) postsynaptic membrane dep"