Explain how action potentials are generated and propagated along neurons.?

Question

Explain how action potentials are generated and propagated along neurons.?

Answer 1

If this is an A2 question, then the answer will vary slightly from Board to Board.

Generalising:

Sodium ions diffuse into the neurone via sodium channel proteins.

The pd switches to about +40mV.

Potassium ions then diffuse out via potassium channel proteins.

The pd switches to about -80mV.

The resting potential is then restored.

Propagation:

Sodium ions move away from the depolarised (+40mV) region.

They move forward to the next Node of Ranvier, lowering the pd to a bit less than resting potential. This slightly opens the sodium channel proteins and so Na+ diffuses in. This further lowers the pd and even more Na+ diffuses in until the neurone is depolarised.

Answer 2

I feel lazy, here is a link

http://en.wikipedia.org/wiki/Action_pote...

next time post this in biology and you'll get a better response.  Plants don't have neurons.