Final answer:
Acetylcholine (ACh) is the neurotransmitter released by motor neurons at the axon terminals. It binds to receptors in the motor end plate, initiating depolarization and creating an action potential in the target cell.
Step-by-step explanation:
Acetylcholine (ACh) is a neurotransmitter released by motor neurons that binds to receptors in the motor end plate. When an action potential travels down the motor neuron's axon, it alters the permeability of the synaptic terminal membrane, allowing calcium ions (Ca²+) to enter.
The influx of calcium triggers the movement of synaptic vesicles to the presynaptic membrane, releasing ACh into the synaptic cleft. ACh then diffuses across the synaptic cleft to bind with ACh receptors in the motor end plate, initiating depolarization and creating an action potential.