changes after death

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