MUSCLE PHYSIOLOGY

Detailed explanation-1: -Once depolarization is complete, the cell must now “reset” its membrane voltage back to the resting potential. To accomplish this, the Na+ channels close and cannot be opened. This begins the neuron’s refractory period, in which it cannot produce another action potential because its sodium channels will not open.

Detailed explanation-2: -Once released by the synaptic terminal, ACh diffuses across the synaptic cleft to the motor end plate, where it binds with ACh receptors. As a neurotransmitter binds, these ion channels open, and Na+ ions cross the membrane into the muscle cell.

Detailed explanation-3: -ACh diffuses across the synaptic cleft and binds to special receptors on the postsynaptic or the postjunctional membrane. The binding of ACh to its receptors produces a conformational change in a membrane channel that is specifically permeable to both Na+ and K+.

Detailed explanation-4: -Once released from the end of the nerve cell, it moves into a space called the synaptic cleft. The synaptic cleft is between the nerve cell from which acetylcholine was released (the presynaptic nerve cell) and the next nerve cell acetylcholine is going to (the postsynaptic nerve cell).