The site where a motor neuron connects to each individual muscle cell is known as the:

• A. Neuromuscular junction
• B. Motor end plate
• C. Synaptic vesicle
• D. Sarcolemma

Answer: (B)

The connection between a motor neuron and a muscle fiber occurs at the neuromuscular junction. This is the complete site where communication happens: the nerve ending releases neurotransmitter into the synaptic cleft, and the muscle’s sarcolemma at the opposite side responds. The motor end plate is the specialized part of the muscle fiber’s sarcolemma within that junction where acetylcholine receptors cluster to receive the signal. So, the neuromuscular junction identifies the overall site of connection, while the motor end plate is the specific postsynaptic region on the muscle. The other options refer to parts of the process or cell: synaptic vesicles contain the neurotransmitter in the neuron, and the sarcolemma is the muscle cell membrane.