THE NERVOUS SYSTEM

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PPonte
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THE NERVOUS SYSTEM

Post by PPonte » Thu May 18, 2006 1:25 pm

Some axons are wrapped in a myelin sheath formed from the plasma membranes of specialized glial cells known as Schwann cells. Schwann cells serve as supportive, nutritive, and service facilities for neurons. The gap between Schwann cells is known as the node of Ranvier, and serves as points along the neuron for generating a signal. Signals jumping from node to node travel hundreds of times faster than signals traveling along the surface of the axon. This allows your brain to communicate with your toes in a few thousandths of a second.


Would someone explain me, please, the sentence in bold?
My reaction to that sentence is to ask why...

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Post by LilKim » Thu May 18, 2006 2:56 pm


baikuza
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Post by baikuza » Thu May 18, 2006 3:33 pm

yes that word sound related to the aim to know the answer.(even i am not already to open the url) :D

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PPonte
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Post by PPonte » Thu May 18, 2006 3:43 pm

I think I made not myself clear.
My doubt is why signals jumping from node to node travel hundreds of times faster than signals traveling along the surface of the axon.

Thank you very much, anyway. For the links. :D

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Post by baikuza » Sat May 20, 2006 9:03 am

hm, i think i was post the answer. where is my post, then? (#_#)

oh, well. see action potential. try it with google.

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Post by nugget » Sun May 21, 2006 3:31 am

hello!

ok i know it seems like it would be opposite, but see it like this
a hurdle race:
every metre thereis a hurdle in which the athlete may jump across. this is the unmylenated axon.

every 10 metres there is a hurdle-- this is the mylenated axon, where the action potential travels from one Node of Ranvier to the next.

as you can tell, who is going to reach the end faster??? the one with less often hurdles. that is how the mylentated axons are faster. there are less amount of current sinks across the axon. all these contribute to time!
hope my analogy helps :D let me know if it doesnt ok?


good luck

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Post by PPonte » Sun May 21, 2006 11:29 am

Nugget, your analogy with some articles I have read make me now understand. Thank you very much! :D
"Now he has departed from this strange world a little ahead of me. That means nothing. People like us, who believe in physics, know that the distinction between past, present, and future is only a stubbornly persistent illusion."
~ Albert Einstein

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