Microbial Decomposition and Time of Death Flashcards
Why can body temperature be used to estimate time of death?
- Metabolic reactions slow and eventually stop after death
2. This causes body temperature to fall until it equals the temperature of the surroundings
What can affect the rate at which body temperature falls after death?
- Air temperature
- Clothing
- Body weight
- Body position (curled up/led flat)
What is rigor mortis?
The stiffening of muscles after death due to the loss of ATP
How does rigor mortis happen?
- After death, muscle cells are deprived of oxygen
- Anaerobic respiration occurs
- Lactate accumulates
- pH of cells decreases, inhibiting enzymes that produce ATP
- Therefore, bonds between myosin and actin become fixed
What factors affect the degree of rigor mortis?
- Degree of muscle development
- Temperature
- How long the body has been there
- Few hours = less rigor
- 48 hours or more = rigor has stopped
What is forensic entomology?
The study of insects on a dead body
How can forensic entomology be used to estimate time of death?
- Type of insect on the body determines how long body has been there
- Life cycle stage that the insect is in
What factors affect the accuracy of the estimate when using forensic entomology?
- Drugs
- Humidity
- Oxygen availability
- Temperature
How is a dead body decomposed?
Bacteria and enzymes begin breaking down tissues immediately after death
How can the extent of decomposition be used to estimate time of death?
The more decomposed the body is, the longer is has been dead.
What factors affect the extent of decomposition?
- Temperature
2. Oxygen availability
What is succession?
The change in types of organisms on a dead body over time
What factors affect the rate of succession?
- Location of the body (above/below ground)
- Temperature
- Oxygen availability
