Question

In: Biology

Nervous System Explain the mechanism of an action potential in a neuron.

Nervous System
Explain the mechanism of an action potential in a neuron.

Solutions

Expert Solution

1.Neurrons are specialised cells that have network inside the body and solely responsible for transfer of information throughout the body. This transfer occurs through electric impulses referred as action potential.

2.Neueons have some extra features that allows and facillitated transfer of signals. This extra features includes dendrites, axon, axon terminal and myelin sheath.

Mechanism of action potential:

Action potential is temporary shifting of resting membrane potential(Negative) towards positive by sudden influx of sodium ions through voltage gated channels.

Events occurred during action potential:

1. Depolarization: voltage gated sodium channels activated by depolarised cell body which results in flow of sodium ions into negatively charged axon and depolarization of axon takes place.

2. Repolarization: This begins with inactivation of sofium channels there by stopping the inflow of sodium ions at the same time opning of potassium channels there by outflow of potassium ions from axon. This combined action results in brinnging back the cell to resting potential.

3. Hyperpolarization: It makes cell more negative than its normal membrane potential.Due to elongated time period of opening of potassium channels, efflux of potassium ion continues which results in negative membrane potential more than resting potential. This is known as hyperpolarization. After closing of potassium channels, resting potential acheived through sodium-potassium pump.


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