Nerve physiology

Axonal  Polyneuropathy changes in EMG

EMG/NCV section Learn about the Brain Learn about nerves Nerve Fibers conduction which carry sensory impulses described in detail  Video below.

Conduction Velocity in nerve fibers

1) One factor we just learned is whether it's or umeylinated.  (In a , the AP travels faster.ALL muscle cells are unwhile nerve cells could be either.)

2) The larger the diameter of the nerve fiber, the faster the conduction velocity.

One extreme would be a thin, unnerve fiber while the other extreme would be a thick, nerve fiber.  In reality we have all sorts of variations of these things.

Nerve Fibers versus Copper Wires

Have you heard the nervous system sends electrical signals? Yes, everybody has.

Do you think the electrical signals travel at the same speed as electricity in a wire?  Most people would say yes.

How fast does electricity move in wires? The conduction velocity in a copper wire is 300 million meters per second. It travels at the speed of light because electricity, like light, is a form of electromagnetic radiation.  The fastest a nerve fiber will travel is 100 meters per second.

So, 300 million meters per second versus 100 meters per second.  Why are they so far apart? A couple reasons at least...

1) What's moving in a copper wire are electrons. For all intents and purposes, electrons don't weigh anything. What's actually moving in a nerve fiber are sodium ions.  A sodium ion would have 11-12 neutrons and protons.  If an electron is a pea, the sodium ion is the SUN

2) Secondly, electrons are moving through a copper wire.  The sodium ions are moving through cytoplasm.

Please continue to basic neural process

Saltuatory conduction Video


Autoimmune cause

Key words : action, potential, nerve, membrane, depolarizes, negative, electron;