Each skeletal muscle fiber is controlled by a motor neuron at a single:

Each skeletal muscle fiber is controlled by a motor neuron at a single:

a. transverse tubule.

b. neuromuscular junction.

c. synaptic cleft.

d. synaptic knob.

Answer: b. neuromuscular junction.

Unlike organs such as the heart that has involuntary contractions, the contracted or shortened part of the skeletal muscles that can be controlled is contracting through the contracted fibres on its parts by the different motor neurons connecting to different neuromuscular junctions. As mentioned above, NMJ stands for Neuromuscular junction which is any junction where motor neurons contact fibers that are part of muscles. At this stage Acetylcholine, a neurotransmitter is released to binds with receptors on the fiber membrane and leads to muscular contractions. Neuromuscular junction therefore presents the critical interface between the two; this is the point where impulses are relayed from motor neurons to muscle fibers in order to cause muscle contractions. The other options that include transverse tubule, synaptic cleft, and synaptic knob do not have a direct implication in regulating muscular contractions by motor neurons