01
Definition
02 03
04 0506
Contents
Decomposition Putrefaction
Colour changes Gas production Liquefaction of
tissues
07
Conditions
affecting
putrefaction
3.
Definition
Post mortem changesrefer to the series of physiological and
biochemical changes that occur in a body after death .
These changes are a result of cessation of ->
1) Respiration
2) Circulation
3)Brain functions
Post mortem changes are of medico -legal importance
4.
LATE POSTMORTEM CHANGES
Decomposition->
Disintegration or dissolution of dead body .
Two major process of decomposition are :
a) Autolysis :
Self destruction of body parts by
endogenous lysosomal enzymes.
1st external sign of autolysis : clouding of cornea .
b) Putrefaction :
Disintegration by bacterial enzymes.
Major bacteria involved are E.coli , Streptococcus
Chief destructive agent is Clostridium Welchii
5.
PUTREFACTION
Changes produced inthe dead body due to putrefaction
are ->
• Colour changes
• Gas production
• Liquefaction of the tissue
6.
Overall first siteof colour change is : Aorta .
Reddish brown discolouration of aortic intima observed.
Externally 1st sign of putrefaction is greenish discolouration visible in the
Right iliac fossa .
This 1st sign of putrefaction starts to appear in :
• 12-18 hours in summers .
• 1-2 days in winters .
Marbling : Bacteria usually spreads through blood vessels , producing H2S .
H2S combines with Hb to form sulphHb
(green pigment)
This stains the blood vessel walls, giving an appearance of linear green
colour marking on skin , termed as marbling .
Occurs around 36-72 hr after death
Medico-legal importance : Helps calculate Time since death
Colour changes
7.
Gases produced areCO2 , NH3 , H2S .
Most important gas for decomposition : H2S
This gas leads to :
• Postmortem skin blisters :
• Gas rigidity/stiffening : entire body bloated , protruding tongue
• Postmortem plunge : oozing of blood from nostrils and mouth
• Foamy liver
Gas Production
8.
Colliquative liquefaction oftissues .
Order of liquefaction :
Earliest : Larynx & Trachea
Early : Stomach , Intestine , Spleen , Liver , Brain , Heart
Late : Prostate in males , nulliparous uterus in female
Last : Bone & Teeth
Liquefaction of Tissue
9.
A) External Factors:
• Temperature : Putrefaction begins above 10 and is optimum between 21 and
38 degree Celsius. The rate of decomposition is twice as rapid in summer as
in winter .
• Moisture : For putrefaction moisture is necessary.
• Air : Free access of air hastens putrefaction
• Manner of burial : Putrefaction is delayed if body is buried in dry sandy soil ,
it is rapid in case of damp , marshy areas .
Conditions affecting the rate of
putrefaction
10.
B) Internal Factors:
• Age : Bodies of children putrefy rapidly and of old people slowly . The bodies
of newborn children decompose slowly .
• Sex: It has no major effect .
• Condition of body : Fat bodies putrefy quicker than lean bodies
• Cause of death : Putrefaction is delayed after death due to wasting
disease ,anemia , severe haemorrhage etc .
Bodies of persons dying from septicaemia undergo rapid
decomposition.
Conditions affecting the rate of
putrefaction
