Changes After Death
Dr. Raid Jastania
Changes After Death
• Decomposition
• Why do we need to know:– Not to misinterpret these changes– Help to determine time (place) of death
Early Changes
• No breathing, no circulation
• Fall in blood pressure
• Metabolism gradually stops
• Loss of neoronal activity– No reflexes, no corneal reflex, fixed dilated
pupils, eye looses the tension
Early Changes
• Primary Flaccidity: complete loss of tone • Muscle may be still reactive for hours (focal
twitching)• Pale skin and conjunctiva• Face may remain blue/red• ?? Hair continues to grow• Loss of sphincter action: pass urine, semen,
regurgitation of food
Rigor Mortis
• Lack of oxygen – no energy – no ATP – glycolysis – lactic acid – acidic cytoplasm – actin and myocin bind
• “Stiff Muscle”• Factors affects Rigor Mortis:
– Level of glycogen– Level of lactic acid– Body built– Temperature, weather
Rigor Mortis
• What is Rigor mortis like if death occurs after – exercise, – electric shock, – in infant, – in elderly– In summer– In winter
Rigor Mortis
• Starts in small muscle around eyes and mouth, jaw, fingers,
• Then spreads from head to legs• Estimated time of death:
– In face: 1-4 hours– Limbs: 4-6 hours– Increase in strength for the next 6-12 hours– Decomposition starts– Secondary flaccidity from 24-50 hours
Rigor Mortis
• Body feels warm & Flaccid: <3 hours
• Body feels warm & Stiff: 3-8 hours
• Body feels cold & stiff: 8-36 hours
• Body feels cold & flaccid: > 36 hours
Cadaveric Rigidity
• Forensic rarity
• Stiffness of muscle occurring immediately at time of death– Finding items in hands– ?emotional/physical stress at death
Post Mortem Hypostasis (Lividity)
• No circulation, relaxation of blood vessels• Blood moves to dependent area• Positioning of body: supine, prone, on side,
on head, hanging• Pink-blue color of the dependent area• May not be apparent in infants, elderly,
anemic• Difficult to see in dark skin, jaundice
Post Mortem Hypostasis (Lividity)
• Blanching: – Around face (not asphyxia)
• Color:– Pink – deep pink – blue – purple– Cheery pink: in carbon monoxide poisoning– Dark red: in cyanide poisoning– In hypothermia: pink around large joints
• Movement of body and change in lividity!
Cooling of the body after Death
• Physical property
• Assumptions:– Temperature was 37 at the time of death– Thermally static environment
Cooling of the body after Death
• Variables:– Mass of body
– Surface area
– Body temperature at death
– Site of reading
– Posture
– Clothing
– Environment temperature
– Winds, humidity, rain
Estimation of the time of Death
• Body temperature– Rectal, ears, nose, liver– Henssge’s Nomogram
• Body temperature• Ambient temperature• Body weight
• Other methods– Gastric contents– Entomologist – Anthropologist
Decomposition
• Air
• Dry, wet
• Water
Putrefaction
• The most common route of decomposition
• Liquifaction of the soft tissue over time
• The warmer the temperature, the earlier the process
Putrefaction
• Visible 3-4 days
• Green discoloration in the right iliac fossa
• Marbling of skin: linear branching ptterns of brown discoloration of skin
• Blistering, skin sloughs off
• Gas formation, swelling of body: face, abdomen, breast, genitalia
Putrefaction
• Increase internal pressure, protrusion of tongue, eyes,
• Bloody fluids
• Within a week: body cavity will burst
• Tissue liquify
Mummification
• Dry condition, eg. Dessert
• Drying and leathery body
• Part or whole body
Adipocere
• Wet condition, water
• Chemical change of body fat to waxy compound material
• Pale, greasy semi fluid material, unpleasant smell
• Firm waxy compound material: takes weeks to months to form
Skeletalization
• More quickly to occur on the surface than in burried body
• Soft tissue will be absent by 2 years
• Tendon, ligaments, hair nails may remain
• By 5 years bone disarticulate
Identification
• Living: coma, amnesia, infancy, mental defect
• Decomposed body
• Following injury
• Mass disasters
General Morphologic Features
• Appearance• Height, weight• Hair color, length• Beard, moustache• Skin pigmentation• Ethnic background
• Eye color• Clothing, jewellery• Tatoo, surgical scars• Injuries, deformities• Age:
– Estimation
– Ossification center
Fingerprint
• Chance of identical finger print is: 1 in 64 million
• Identical twins
•
Teeth
• Identification of person
• Age
• Bite marks
Identification of origin of tissue
• Why:– Blood, semen, saliva..– Come from suspect for victem– Match of human remains– Resolve paternity/maternity
Identification of origin of tissue
• DNA profiling:– Matching– Paternity, maternity– Sampling:
• Nucleated cells: wbc, hair root bulb cells, sperms, buccal smear..
Identification of origin of tissue
• Human Remains– Are they human– Is it one or more bodies– Sex: skull, pelvis– Age
• Up to 20-25 years, age can be estimated within couple of years
• >25 years more difficult to estimate
Top Related