Question

What are the events which occur in a motor neuron and muscle to change an electrical signal to a chemical signal, and turn on muscle contraction?

Answer 1

Events occuring in the motor neuron-

Generation of action potential by the stimulus

Transmission of this signal to the cell body to axon to the axon terminal.

At neuromuscular junction-

Release of neurotransmitters at the junction causes chemical signals and binding of the neurotransmitter to the receptors on the muscle cell takes place.

In muscle cell-

After binding of the neurotransmitters to receptor, again electrical signal is generated and carried forward to the T tubules which causes releasd of calcium.

This calcium binds to troponin and unmasks the actin binding sites on myosin.

Acting bibds to myosin , formation of cross bridges takes place and contraction occurs.