Neurotransmitter of the neuromuscular junction

Question

Name the neurotransmitter of the neuromuscular junction? Explain how nervous system triggers muscle contraction?

Answer 1

The nervous cells which trigger the muscle contraction are motor neurons. The neurotransmitter of the motor neurons is an acetylcholine. Whenever a motor neuron is excited, the depolarizing current flows all along the membrane of its axon till reaching the synapse at neuromuscular junction (that is, the neural impulse passage zone among the axon extremity and sarcolemma). Close to the axonal extremity, the depolarization permits the entrance of calcium ions into the axon (note that, calcium as well consists of a relevant role here). The calcium ions stimulate the neuron to discharge acetylcholine in the synapse.

Acetylcholine then joins to special receptors in an outer surface of the sarcolemma, the permeability of this membrane is modified and an action potential is made. The depolarization is then conduced all along the sarcolemma to sarcoplasmic reticulum that therefore discharges calcium ions for sarcomere contraction.