Dr Karl

Wow.

Ah, so imagine you've got a nerve and it's a hollow tube and the longest and fattest nerve in your body is a sciatic nerve running down to the tips of your toes from the base of your spine.

So imagine you've got this pipe, say we'll call it like a... It's a plastic pipe and there's all sorts of complicated stuff inside.

We're discovering microtubes, all sorts of stuff.

But the wall...

By selectively allowing sodium to get out and potassium to come in, it maintains an electrical potential.

So there's 80 millivolts negative, 80,000 millivolts on each of the cells in your body, especially nerve cells.

The ones that are different are the ones in your ears.

They've got 140 millivolts because that's a special trick to make your ears more sensitive.

But getting back to general, you've got this potential difference, this voltage across the cell wall of your nerve.

And for whatever reason, it breaks down suddenly.

Suddenly, all the pumps switch off.

So you've got these things called sodium-potassium pumps.

When I went through medical school, there was only one.

Now there's about 19.

And a mutation in one of them leads to you not feeling any pain.

Look up the past Pakistan circus athletes, but that's a different story.

So normally that potential is maintained.

by pumps, which are powered by ATP.

They stop.