Question

Neurons excite muscle cells to contract at the neuromuscular junction. Which of the following is not a feature that occurs at this junction?

A) Opening of voltage gated ion channels in motor neuron
B) Acetylcholine receptors on the muscle cell bind to ligand
C) Release of calcium by the motor neuron
D) Depolarization of the motor neuron axon terminal

Answer 1

At the neuromuscular junction, the opening of voltage-gated ion channels in the motor neuron terminals occurs, allowing the influx of calcium. This calcium release triggers the fusion of synaptic vesicles containing acetylcholine with the presynaptic membrane. Acetylcholine then binds to acetylcholine receptors on the muscle cell, leading to the opening of ligand-gated ion channels and the influx of cations, which depolarizes the sarcolemma and initiates muscle contraction.

Step-by-step explanation:

At the neuromuscular junction, the opening of voltage-gated ion channels in the motor neuron terminals occurs, allowing the influx of calcium. This calcium release triggers the fusion of synaptic vesicles containing acetylcholine with the presynaptic membrane. Acetylcholine then binds to acetylcholine receptors on the muscle cell, leading to the opening of ligand-gated ion channels and the influx of cations, which depolarizes the sarcolemma and initiates muscle contraction.