Praise be to Allah.
There is nothing wrong with dissecting animals and insects etc. for academic purposes because there are clear benefits in doing so. The same applies to dissecting humans for the purpose of learning, on the condition that the body that is dissected is not that of a Muslim, because the sanctity of a Muslim after he dies is the same as when he is alive. It is OK to dissect a pig for academic purposes, but it is naajis (unclean, impure), so you have to touch it indirectly [e.g., wear gloves – translator]. If you need to touch it directly, that’s fine, then you must wash your hands afterwards. It is OK to touch human bones if they are accessible, because a human does not become naajis when he dies.