What is the speed of our impulse??

Do you mean the speed at which information moves along a nerve? If so, below may help you get started.

Here is some information on pain signals:

http://72.14.203.104/search?q=cache:XfE5uPM4kwwJ:www.pa...clnk&cd=4&lr=lang_en

Here are some clips from a techncal article on the question. If it sounds as if this is the sort of information you are looking for, you can read the rest of the article at the site.


For the difference between the speed in various nerve tissues, e.g. spinal, cortical, etc., see this article, chapter 3.

http://72.14.203.104/search?q=cache:iVgvFddTuuEJ:www.wb...&cd=11&lr=lang_en#19

For a fairly simple comparison of nerve tissue as circuitry, see:

http://slashdot.org/askslashdot/99/03/07/1317249.shtml

See the answer by Bid 28274.

Some excerpts:

“The nerve is a binary device: it can only transmit a voltage difference (wich is made by the K+/Na+ doors & pumps). At normal state, the nerve will have a -70mV potential. When it's excited up to -55mV, the rection of the doors is unstopable and the potential go up to -30mV. After, the nerve just repolarize itself to -55mV, goes into an Hyperpolarisation (-90mV), and come back to normal. “

“This whole process cannot be modulated: It's on or off, you can't mess with the voltage of the reaction. So the signal is binary: 1 or 0.”

“The time of the whole process, before it can be done again, is about 4ms, which mean low BitRate, and a lag of about 1-2ms minimum (before it reach the top of the curve).”

“The fastest nerves have a frequency of about 200Hz to 300Hz, wich mean that on a single fiber, you can only do 300bps maximum.”

“The next problems with nerves as a data transport: they're slow. The fastest nerves can go at about 280mph.”

“The longest nerves (in the legs) are about 1 meter long...”

A factor is nutrition. Nerves require “...oxygen and oligoelements (most K/Na/Ca) [ from surrounding ] blood vessels along them.”

Re “... nevroglious cells. For normal nerves, only Schwann cells are required, ... in large number enough to produce the myelin gain.”

“Nerves don't regenerate, and they don't reproduce. So, if you go to the top 300bps for too long, your cells might dies, and they'll nerver be replaced. The axon (the long tail) CAN regenerate, but it take time (some months).”

I'm sure someone here with a strong background in biology can give you a better answer, but this may help you start out.