How the Body Works : A Nerve Impulse

The conduction of nerve impulses relies upon the movement of electrically charge ions across the nerve cell membrane. When a nerve is resting, or polorized, there are more potassium ions than sodium ions inside the cell, with an opposite ratio outside. Sodium ions are actively kept out of the cell by an energy consuming pump mechanism. This maintains a negative charge on the inside of the cell and a positive charge on the outside. When an impulse travels along the nerve, sodium ions flood into the cell and make the inside of the cell positive with respect to the outside. This produces a rise in the electrical potential across the cell membrane. After the impulse has passed, potassium ions leave the cell, restoring the negative charge within the cell and the positive charge outside it. While this resting situation is being restored another impulse cannot be generated.

Category:

Howto & Style

Tags:

• A
• Nerve
• Impulse

[andrew567567]

wooow im naked right now! w

[avocadomilk]

what stops the impulses from traveling backwards?

[vestraya]

@avocadomilk recall that the membrane can only produce another action potential when it is at the resting portential. thus, during the refractory period right after the an action potential, the cell membrane cannot produce another action potential becuase it is hyperpolarized. so, a new action potential can only be triggered at the leading edge o the first polarized area.

got it from my text book.

[legofilmer2000]

........ I didn't understand a WORD in that video!!

[dev009bitoo]

realy hlpfl...

[psipsychologytutor]

straightforward~ thx

[z1jj]

@avocadomilk

-If you artificially stimulate an axon from the center, it WILL travel in both directions away from the artificial stimulation. It just depends on where the action potential propagates.

[BaltoMovie]

Does anyone know how long it's takes for the Nerve to pump na+ out and suck k- in?

I'm guessing only a few mill-seconds but it's just so amazing I can't believe it

[ryan110110110]

Research the refractory period + synapses and you will find out.

Plus if you think, the receptor, or any other means of starting an impulse, will be at one end of the neurone so the impulse is just going to travel along the axon, rather than going half way and jus turning back :P

[Giddy1993]

Wow heaps good :D

thanks :D

[WanahLovesAli]

This video was helpfull :)