MEDICAL PHYSIOLOGY

Detailed explanation-1: -At the neuromuscular junction, synaptic action increases the probability that an action potential will occur in the postsynaptic muscle cell; indeed, the large amplitude of the EPP ensures that an action potential always is triggered.

Detailed explanation-2: -[11] In unmyelinated axons, depolarization of the cell membrane must spread to the immediately adjacent region of the membrane, raising the potential passively until reaching the threshold voltage. Thus, the action potential propagates as a continuous wave of depolarization.

Detailed explanation-3: -Depolarization is caused by a rapid rise in membrane potential opening of sodium channels in the cellular membrane, resulting in a large influx of sodium ions.

Detailed explanation-4: -Once the action potential reaches the axon terminal, what happens next? depolarizes a neuron, increasing the likelihood of an action potential.