Yesterday in school, this punk....I won't get into details, anyways he knees me pretty hard, right into the thigh, well after that I push him off and he leaves. The pain was pretty bad, I had to ta ALL weight off of it, and when I sat down in my desk, my hands were cringing, the ACTUAL pain faded after a few minutes but if I were to press somewhat i could feel for it for the whole day, and if i pressed in deep, even more. Today it was better, the only way I recognize its there is if I press really hard into.

My question is what happens to the muscles or nerves in the leg when you get a dead leg?

Sounds like a muscle contusion. I doubt there'd be any nerve damage, so I wouldn't worry about that. After the hit, your quadricep just didn't want to contract (to protect itself), hence the pain. AKA "Charlie Horse".
Treat it as any other injury Rest/Ice/Compression/Elevation for the first 48 hours, then alternate Ice/Heat for the next week, if need be.

You may have been struck on gall bladdr 31 or 32. Very common pressure point strike.
Next time slap the area about half as hard as the attacking force and then do a light massage over it for about 30 seconds. the residual effect will be greatly reduced.

your gall bladder is in your abdomen....

You guys are a scream! My grade school buddies use to do that to each other all the time, we would run up to one of us and knee the guy in the thigh. Yeah it hurts like hell doesn't it?!

[QUOTE]Originally posted by karate-do:
your gall bladder is in your abdomen....[/QUOTE]

Karate-do, Alan Shindsharonjr is talking about getting struck on the pressure points on the gall bladder meridian, not on the actual gall bladder itself.