Time of death

Question 1

ways to estimate time of death

Answer 1

1. body temperature
2. rigor mortis
3. extent of decomposition
4. forensic entomology ( insect )
5. stages of succession

Question 2

how can body temperature be used to estimate time of death

Answer 2

after death, respiration stops and body temperature falls until equal temperature to its surroundings (ambient temperature)

Question 3

factors that effect rate of body cooling after death

Answer 3

• body size as rate of cooling decreases due to larger mass
• body position as rate of cooling is increased the more surface area exposed
• clothing as it acts as an insulator
• air movement as faster air means faster convection of heat away from the body
• humidity

Question 4

process of rigor mortis

Answer 4

• following death, the sarcoplasmic reticulum decomposes
• this releases calcium ions into the sarcoplasm
• calcium ions bind to troponin and the troponin changes shape
• this moves the tropomyosin allowing myosin to bind to the actin binding site
• myosin cannot let go once the ATP has run out

Question 5

what is autolysis

Answer 5

the destruction of a cell through the action of its own enzyme

Question 6

Process of decomposition

Answer 6

1. lower abdomen discolours to a greenish colour
2. as the discolouration spreads it turns reddish then purple-black
3. anaerobic bacteria produce a range of gases in the intestine causing the body to bloat and smell
4. gases are released as further tissue decomposition occurs and the body deflates
5. fluids drain away from the body and tissues shrink
6. rate of decomposition slows as the body dries out