Post Mortem Changes Flashcards
Recognition of the natural processes which occur after death.
Early:
> Algor mortis - change in body temperature
> Livor mortis - blood in the lower, or dependent, portion of the body postmortem, causing a purplish red discoloration of the skin.
> Rigor mortis - stiffening of the limbs of the corpse caused by chemical changes in the muscles
Late:
> Autolysis and putrefaction - Autolysis is the process by which digestive enzymes within the body cells break down carbohydrates and proteins. Putrefaction is the predominant cause of tissue degradation and is due to bacterial activity.
> Mummification - Autolysis is the process by which digestive enzymes within the body cells break down carbohydrates and proteins. Putrefaction is the predominant cause of tissue degradation and is due to bacterial activity.
> Adipocere - a greyish waxy substance formed by the decomposition of soft tissue in dead bodies subjected to moisture.
> Skeletonisation - final stage of decomposition, during which the last vestiges of the soft tissues of a corpse or carcass have decayed or dried to the point that the skeleton is exposed.
Recognise the difficulties in ascertaining the timing of death.
Determining the exact timing of death is challenging due to various factors. Postmortem changes like rigor mortis, livor mortis, and algor mortis can provide clues, but they vary depending on the person’s health, environmental conditions, and the cause of death.
Decomposition also complicates timing estimates, as its rate depends on temperature, microbial activity, and other factors. Additionally, external influences such as weather, drugs, and the person’s physical condition can affect the postmortem process.
Forensic methods like temperature measurement or insect activity provide estimates, but they are not always precise.
Ultimately, determining time of death is a complex process that relies on expert judgment and various imprecise indicators, leading to time-of-death estimates rather than exact moments.
Recognise and distinguish post mortem changes from features of natural disease and trauma.
Postmortem changes, like rigor mortis, livor mortis, algor mortis, and decomposition, occur after death and are influenced by environmental conditions.
These changes follow predictable patterns, such as muscle stiffening, blood pooling, body cooling, and tissue breakdown, which differ from features of natural disease or trauma.
Natural disease (e.g., heart failure, cancer) may cause tissue damage or fluid accumulation, while trauma (e.g., fractures, bruises) shows signs of active injury, bleeding, or inflammation.
Postmortem injuries tend to be irregular, without signs of active bleeding or tissue response.
Forensic pathologists use these differences to distinguish between postmortem changes and signs of disease or trauma to determine cause and manner of death.
