Anth 245 1st edition Lecture 25Outline of Last lecture- Jackson Couple Poisoning - Charles Norris - The risk of tetraethyl gasolineOutline of Current Lecture - Fresh stage- Putrefaction Stage- Bloating Stage- Late Stages- Variables in Rate of DecayCurrent LectureBODY DECOMPOSITION Fresh stage: Autolysis - "self-digestion" - self-destruction of cells due to activity of intracellular enzymes - Liver, pancreas first - Begins within minutes or hours of death - No gross (macroscopic) changes noted at first - Byprodu ts fuel putrefaction stage Algor Mortis (also fresh stage) - body cooling after death - Rule of thumb: - 1.5 degrees Fahrenheit loss for first 12 hours - Critical assumptions: - Room temperature - Decedent had normal antemortem body temperature (98.6) - Take context into account - Many variables affect rate of heat loss These notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.Fresh Stage: Livor Mortis - The accumulation of blood, causing lividity (discoloration) - Begins 30-120 minutes after death - Constricted tissues blanch - Fixation occurs 8-12 hours Fresh Stage: Rigor Mortis - Body stiffening - Muscles lock in place - Sustained connection of actin/myosin fibrils due to loss of ATP - Begins 1-2 hours after death - Maximum rigor typically occurs at around 12 hours after death - Wanes over the next 24-36 hour period Putrefaction Stage - Decomposition of tissues due to internal bacterial activity - Occurs 24+ hours after death - 1st Green discoloration of abdomen - Next: entire body becomes discolored - Skin slippage - Purging - fluids purge from orifices due to pressure changes internally - Not trauma - a reaction of body to putrefaction and bloating - Marbling - decomposition of blood cells and spread of internal bacteria to blood vessels Bloating Stage - Occurs 60 to 72 hours after death - Bloating due to release of gas from endogenous (internal) bacteria - typically seen in face, abdomen, neck - Begins in the abdomen - With time, tissue ruptures or gases leak from orifices Late Stages- Decay - Loss of soft tissue leaving cartilage, ligaments, hair - Skeletonization - Loss of all soft tissue leaving only bones - Drying of bone (degreasing) Variants - Mummification - Occurs in warm, dry environments - Adipocere formation - Occurs in warm, humid environments or when bodies are submerged in water Important Variables in Rate of Decay - temperature - Insect accessibility - Burial and depth - Soil pH - Carnivore activity - trauma - humidity/aridity - rainfall - body size/weight - clothing -
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