1) An action potential is propagated down the lower motor neuron
2) Calcium levels increase in the cytoplasm of the muscle cell
3) Acetylcholine binds its receptor and causes depolarization
4) Vesicles containing glutamate fuse with the nerve terminal
5) Contraction.
Answer:
4,1,3,2,5
Explanation: Glutamate is the neurotransmitter that excites the motor neurons and produces action potential in motor neurons. Then this action potential travels down towards the axonic terminal where it would cause release of acetylcholine. ACh then binds to postsynaptic membrane causing depolarization of sarcolemma. Calcium ions are released into the sarcoplasm resulting in muscle contraction.