The muscle fiber and the nervous system connect together through the neuromuscular junction. This junction is a type of synapse that essentially works like a bridge connecting two masses of land. An excitatory signal goes from a neuron to a muscle cell thanks to synaptic transmission. A motor neuron is excited and calcium enters the neuron to encourage neurotransmitter exocytosis. The neurotransmitter heads into the synaptic cleft and somatic motor neurons secrete acetylcholine.
Acetylcholine binds to a muscle cell membrane's acetylcholine receptors after diffusing over the cleft and then opens ion channels to allow the diffusion of sodium ions into a muscle cell. This excites the cell membrane of a muscle cell because sodium causes depolarization; this in turn is caused by sodium being a positive ion. At this point, the excitatory impulse is deep in the muscle cell and it goes deeply into a muscle cell with the help of T-tubules, a type of striation that serves as the base for electrical impulse travel. The action triggers calcium to come from the sarcoplasmic reticulum to the cell's interior, resulting in muscle cell contraction, and this process occurs throughout every minute of the day to ensure that the muscles are functioning properly.Learn more about Science