Autopsy, Necropsy & Post Mortem

• Post Mortem


  Medical examination/inspection of body after death
• Autopsy


  Study of the self
• Aim of post mortem


  • Determine the cause of death
• Post mortem


  • Often classified within the field of forensic pathology
  • Areas studied: Histopathology, Toxicology, Blood and DNA analysis
• Histopathology


  Study of how tissues react to pathogens, temperature, oxygen deficiency, chemical imbalance - these changes can indicate chronological order of events
• Histopathology is useful in sudden death where trauma and poisoning are ruled out
• Post Mortem Changes


  • Rigor Mortis
  • Livor Mortis
  • Tardieu spots
  • Algor Mortis
  • Purge fluid
• Rigor Mortis


  Muscle fibres require ATP for relaxation - once depleted, actin and myosin remain complexed, stiffening muscles
• Livor Mortis


  Bluish purple under the skin, appears 30 mins-2 hrs after death, can occur earlier if poor antemortem circulation
• Tardieu spots


  Purple to black spots from the rupture of capillaries
• Algor Mortis


  Process of body cooling as heat production ceases
• Purge fluid


  Fluid that drains from the body
• Cell breakdown


  1. Lysosomes release enzymes (proteases, nucleases, lipases) into cell cytoplasm

  2. Self-digestion - AUTOLYSIS (temperature) occurs within minutes
• Autolysis occurs at a different rate in different organs, fastest in pancreas and stomach
• Putrefaction


  1. Bacterial and/or fungal growth - bacteria escapes the intestinal tract

  2. Alters tissue structure (neck, abdomen, shoulders and head turn to discoloured green, bloating, skin blistering, loss of hair, fingernails sink back into fingers, marbled skin tone, body turns black-green and fluids drain)
• Histology contributes to the cause of death in more than 50% of post-mortems
• Histology


  • Can aid in assisting discrimination between post-mortem artefact from an antemortem injury
  • Limitations in significantly decomposing tissues - excessive autolysis and putrefaction hamper the histological interpretation of both disease and trauma
• Taphonomy


  Science / knowledge of tomb/burial
• Necropsy


  The examination of a dead animal to determine the cause of death