Question

part b (2 of 6)
2 tries left
the neuromuscular junction is a well - studied example of a chemical synapse. which of the following statements describes a critical event that occurs at the neuromuscular junction?
acetylcholine binds to its receptor in the junctional folds of the sarcolemma. its receptor is linked to a g protein.
acetylcholine is released and moves across the synaptic cleft bound to a transport protein.
acetylcholine is released by axon terminals of the motor neuron.
when the action potential reaches the end of the axon terminal, voltage - gated sodium channels open and sodium ions diffuse into the terminal.

Explanation:

At the neuromuscular junction, the motor neuron's axon terminals release acetylcholine into the synaptic cleft. Acetylcholine binds to nicotinic receptors on the muscle - fiber's sarcolemma, not G - protein linked receptors. It moves across the synaptic cleft freely, not bound to a transport protein. When the action potential reaches the axon terminal, voltage - gated calcium channels open, not sodium channels.

Answer:

Acetylcholine is released by axon terminals of the motor neuron.