Forensic Medicine Flashcards
Under what circumstances is identification in the living essential?
Amnesia, dementia, post-coal states.
Why is identification essential?
Human rights, criminal investigation, civil law, social function, cultural/religious/psychosocial reasons, assessment of injuries.
What are the two main methods of identification after death?
- Comparative
2. Deductive
How are individuals identified after death?
- Are they human?
- Expected environment/circumstances OR unrelated to environment/circumstances?
- Gender
- Age
- Stature
- Additional features (race, hair, eyes, facial hair, facial characterisations, tattoos, piercings, scars)
What are the two main areas of the skeleton that are used to determine gender?
Skull and pelvis.
In what instance can sexual characteristics be obscured?
Decomposed or burnt body.
What is used to distinguish approximate age at each stage of life?
- Fetus and neonates - bone development using ossification centres.
- Childhood and adolescence - assessment of epiphyses.
- Adult - increasing difficulty
What is the most valuable indicator from infancy to adulthood?
Teeth.
Discuss stature in identification.
- Difficult to do with precision, people may not have had their height measured accurately in life.
- Individual bones of lower limb are most useful for calculation of height.
What resources can be used for comparison when identifying a body?
Medical records, dental records, fingerprints, DNA profiling, facial reconstruction, radiology.
Is precise timing of death possible?
NO (depend on environment in which the body lies after death also toxicological considerations and stomach emptying).
What are the early changes seen after death?
- Temperature.
2. Post-mortem hypostasis (lividity, liver mortis).
Discuss the main points associated with temperature after death.
Temperature degrades but too many variables to calculate.
- temp of body and environment can vary at death.
- Curve = Initial drop and then a slight rise due to decomposition.
Define post-mortem hypostasis.
Settling of blood vessels under action of gravity with areas of pressure pallor.
When is post-mortem hypostasis fastest?
In the warmth.
When is post-mortem hypostasis not identifiable?
During putrefaction.
What is ‘cheery pink’ liver mortis indicative of?
CO poisoning
How long does liver mortis usually take?
1-2 hours and fully established by 6-12 hours.
Define rigor mortis.
Stiffening of muscles after death which arises in a cycle wearing on over a period and the off again.
What does rigorous mortis lead to?
Rigidity of musculature and fixation of joints.
What is “cadaveric spasm”?
Contraction of small muscles particularly in people active before death.
What is ‘pugilistic attitude’?
Death in high temperature causing flexion deformities and protruding tongue, haemorrhage under skull and broken bones.
What are the main late changes seen after death?
- Putrefaction
- Autolysis
- Adipocere formation - saponification
- Mummification
- Skeletonisation
What is adipocere formation?
Saponification. Special form of degradation e.g FAs in adipose and ionic solutions. Micro-organisms avoid this.
What is autolysis?
Endogenous proteolytic degeneration with enzymes.
What is putrefaction?
Microbiological degeneration.
What is mummification?
Desiccation usually with warmth. Brown/leathery skin. Also inhibits putrefaction and autolysis.
What is skeletonisation?
Disappearance of soft tissue, depends on exposure and can be extremely variable.
What other changes can be seen after death?
- Maceration (especially of stillbirths - autolysis alone)
- Embalming (inject into blood vessels)
- Post-mortem mutilation (causes mechanical OR predatory damage).
What type of toxin is released on cell death?
Endotoxin.
