Forensic medicine Flashcards
Definition of death
Cessation of life either heartbeat, respiratory movements, circulation or absence of carotid pulse
3 types of death?
Cellular
Brain
Somatic
What is cellular death?
cessation of cellular respiration followed by loss of metabolic activity
is death a sudden event?
No it is a process
how long after death does some cells live?
WBC up to 12 h
Neurons 3-7 minutes
Bone and skin days
define somatic death?
Loss of vital signs such as reflexes, heartbeat and respiration
The individual is irreversible unconscious
Define brain death?
Clinical diagnosis with irreversible damage to the brain
Early PM changes?
Livor mortis
Rigor mortis
Algor mortis
Late PM changes
Decomposition
Mummification
Adipocere
Skeletonization
Early PM signs in the eyes?
Loss of corneal reflex
Retinal vessels fragment - trucking/shunting
Loss of intraocular pressure
When may Livor mortis be absent
young
Old
Anemia
Major blood loss
why do we get livor mortis
hypostasis and RBC accumulate where gravity is highest
Hypostasis may have different colors in which cases
- Cherry pink in CO paisoning
- Brick red in cyanide poisoning
- Bronze in clostridium perfringens infection
Nysten rule of rigidity
< 30 min nothing
30 min-3h jaw and face become rigid
6h-24h all muscles are rigid
>24h rigidity starts to diminish
difference between rigor mortis and cadaveric rigidity?
Rigor mortis is a physiological phenomenon occuring over time
Cadaveric rigidity is due to the person clinching muscles at time of death (stress)
Algor mortis timing?
first 3-4h drop by 1C/h
what influences algor mortis?
Mass of body
Surface area of body
T at death
Posture of body
Clothing
Environment (warm/water)
where to take temperature
Rectum or liver
when does signs of decomposition occur?
in warm climate abdomen above cecum turns green after 3-4 days
What is marbling?
discoloration of vessels due to bacteria multiplication and hemolysis
skin manifestation of decomposition?
blistering and peeling
why do we see bloating? what else can we see?
Bacteria cause gas
Also reason for eyes and tongue protruding
What is purge fluid?
Due do decomposition the increased pressure in the body forces fluid out of the mouth and nose
why does mummification happen?
if there is a very warm and dry environment body desiccate instead
what age s mummification common?
infants because they are sterile
Describe mummification appearance?
Brown
Dry
Leatherly
dehydrated and stiffened
define adipocere
grave wax formation of fat, most commonly in water
normal timing of adipocere
1-2 months
Define skeletonization
loss of soft tissue (not tendons) takes 2 years
after 5 years ONLY bone
the 3 times of death?
Physiological:
Estimated
Legal
3 ways of estimating TOD
looking
Touching
Measuring
time of first sign of decomposition?
AFTER 36h
temperature and timing indicating PM
warm and flaccid indicated <3h
warm and stiff indicated 3-8h PM
cold and stiff indicates 8-36h PM
cold and flaccid indicated more then 36h
how does rigor mortis progress
starts in small muscles
startes 0,5-3h PM
decays after 36h