Acetylcholine

Multiple Choice

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) opens voltage-gated Na⁺ channels in skeletal muscle fibers, which causes depolarization of the muscle fibers, and always depolarizes skeletal muscle fibers and postganglionic neurons
E) all of these