Final answer:
The term for a synapse that releases acetylcholine at the neuromuscular junction is the End plate. It is where ACh is released from the presynaptic axon terminal, crosses the synaptic cleft, and binds to receptors on the postsynaptic membrane to stimulate muscle contraction.
Step-by-step explanation:
The term that refers to a synapse that releases acetylcholine from the presynaptic axon terminal is D. End plate. An end plate is the specialized area of the muscle membrane at neuromuscular junctions.
Neurotransmission is the process where a neurotransmitter, in this case, acetylcholine (ACh), is released after an action potential arrives at the axon terminal of the motor neuron. This leads to the influx of calcium ions, which drives the movement of synaptic vesicles towards the presynaptic membrane. As the vesicles fuse with the membrane, ACh is released into the synaptic cleft. It then diffuses across this gap, binding to ACh receptors at the motor end plate on the postsynaptic membrane, which is part of the muscle cell.
This binding of ACh to its receptors results in the creation of an end-plate potential, a localized depolarization event. Eventually, if the signal is strong enough, this will trigger an action potential in the muscle cell initiating contraction. Remember, the neurotransmitter ACh is what's released, but it is the end plate that characterizes the type of synapse in the context of neuromuscular communication.