Islam and Post Mortem — In Short

Allah says: "And verily we have honored the children of Adam." (Quran 17: 70)
A human body is sacred even after death. The Prophet (s.a.w) said: "Breaking the bone of a dead person is similar (in sin) to breaking the bone of a living person". (Sunan Abu Dawud, Sunan Ibn Majah & Musnad Ahmad)
The prophet forbade mutilation of the human body.
However ulama have allowed post mortem under the doctrine of zaruurat (necessity).
Postmortem is allowed in the following condition in Islam:
1. To confirm the cause of death in a criminal case
2. To know the disease that cause the death.
3. For teaching and learning purposes in the medical field. And it is compulsory to bury the dissected dead body.