MEDICAL PHYSIOLOGY

Detailed explanation-1: -The voltage-gated channels represent another major class of ion channels. Unlike ligand-gated channels, voltage-gated channels have no natural ligand. They open and close as a result of changes in membrane potential produced as electrical currents move through biological systems.

Detailed explanation-2: -Voltage-gated channels are proteins that can respond to small changes in membrane potential or the distribution of charge across a phospholipid bilayer. Voltage-gated channels play a vital role in the process of nerve cell communication through their involvement in production of an action potential.

Detailed explanation-3: -Ion channels are “gated”, i.e. they open in response to a specific stimulus, such as a change in membrane potential (voltage-gated ion channels) or the binding of a neurotransmitter (ligand-gated ion channels).

Detailed explanation-4: -A voltage change that reaches threshold will cause voltage-gated sodium channels to open in the axonal membrane. The influx of sodium causes the rising phase of the action potential, but the ion flow also depolarizes nearby axon regions. As the depolarization reaches threshold, the action potential moves down the axon.