post-mortem examination or autopsy, systematic examination of a cadaver for study or for determining the cause of death. Post-mortems use many methodical procedures to determine the etiology and pathogenesis of diseases, for epidemologic purposes, for establishment of genetic causes, and for family counsel. Post-mortems may be performed at the request of the authorities in cases of unexplained and suspicious death or where death was not attended by a physician. In other circumstances post-mortem examination may be performed only with the consent of the deceased's family or with permission granted by the person himself before death. These examinations are more frequently being used for the acquiring of organs and tissues for transplantation. Valuable medical information can be learned from a post-mortem examination. Legionnaire's disease, for example, was discovered as a result of autopsies, and improved safety standards have resulted from the examination of the bodies of crash victims.