Acetylcholine
A)opens voltage-gated Na+ channels in skeletal muscle fibers, which causes depolarization of the muscle fibers
B)may decrease the permeability of the motor end plate to Na+ and K+ when combined with the receptor sites on the motor end plate
C)always depolarizes skeletal muscle fibers and postganglionic neurons
D)does both a and b
E)does both b and c

Question

Quizplus · Accepted Answer

Acetylcholine always depolarizes skeletal muscle fibers and postganglionic neurons by binding to nicotinic receptors, leading to an influx of Na+ and efflux of K+.