Anatomy serves four purposes:
1) When coupled with the skill wrestling it allows the player to toggle "stun" which when used (must punch your opponent once stun is toggled on) will paralyze their opponent for a couple of seconds if successful.
2) When using a weapon GM Anatomy increases the maximum damage you will do to your opponent.
3) With the healing skill Anatomy allows you to resurrect other players and on the whole heal more damage.
4) With just GM Evaluating Intelligence and Anatomy (no wrestling) you will have a 'virtual' wrestling of 100 when it comes to defensive wrestling.

The best way to train Anatomy is to run a simple macro that uses the anatomy skill, and then targets a random blue. Run this macro at a popular location such as Britain Bank.