An autopsy is a detailed medical exam of a deceased person's body.
Your doctor will tell you who to contact if you want to donate your loved one's organs to science. They will also discuss with you the benefits and drawbacks of an autopsy and what the pathologist will be looking for. Ask about the cost of the autopsy. Some autopsies are done for free. But many hospitals charge for the procedure. If the law requires an autopsy, there is no charge.
Autopsies will not interfere with funeral arrangements. The procedure can take a few hours. Once it's done the hospital will tell the funeral home. The mortician then embalms the body and gets it ready. The autopsy cuts (incisions) won't be visible. Open-casket funerals can still be done.