1. POST MORTEM CHANGES Signs of Death And Postmortem changes after death
Immediate Changes
Early Changes
Late Changes

2. Immediate changes
Permanent Cessation of Brain function
Complete Cessation of Circulatory function
Entire and permanent cessation of Respiratory function

3. Permanent Cessation of Brain function:
Loss of Sensations; viz,
touch, pain and temperature
Loss of reflexes
Total loss of E.E.G. Rhythem
Confirmation of Brain- stem death

4. Brain –stem death:
The patient must be comatose state at least six hours.
No Abnormal Decorticate or decerebrate postures should be present
All brain-stem reflexes must be absent.

5. Pupils should be fixed
No Corneal reflex
Absent of the oculo-cepralic reflex
Absent vestibulo-ocular reflexes
No Motor responses
No Gag reflex
No Respiratory movements
After disconnection of ventilator.

6. Complete Cessation of Circulatory Function
Magnus’s test
Finger nail test
Diaphanous test
Icard’s Fluorescein test
Heat test
Artery incision test
A flat E.C.G. for a continuous period of five minutes

7. Entire and permanent cessation of respiratory function
Mirror test
Feather test
Winslow’s glass water test.

8. Suspended Animation
It is a condition in which the vital functions of the body are at such a low level that they cannot be appreciated by clinical examination
Apparent death
This may last few seconds to minutes.
Voluntary- by yogis
Involuntary – drowning, electrocution, heat stroke, typhoid fever etc.

9. Early Changes Changes in the eye Changes in the skin
Cooling of the body/Algor mortis
Post mortem lividity/Hypostasis
Rigor mortis/Cadaveric rigidity

10. Changes in the eye Loss of Clear Glistening Dry, Cloudy and opaque
Corneal Changes;
Loss of Clear Glistening
Dry, Cloudy and opaque
Loss of reflexes
Light reflex abolished
Intra Ocular tension falls, eye balls become flaccid and sink in the orbit
Blood flow in the retina becomes dotted and segmented look.

11. Optic disc looks pale.
Pupils fully dilated in the early stage and constict later due rigor mortis.
Brownish discolouration of the sclera due to cellular debris and dust
Taches Noires

12. Changes in the Skin Loss of its translucency
Pale and Ashy white appearance
Loss of Elasticity
Wounds will not gape if it is inflicted after death
Wounds caused during life will retain their characteristic features.

13. Cooling of the body Imbalance between heat production and heat loss.
Loss of heat of body by means of conduction convection and radiation, till it balances with the temperature of surroundings.
Rate of cooling is fast during first few hours and later slows.

14. Temperature is recorded by Chemical thermometer- Thanotometer 25 cms.
Recording of temperature :
Normal temp. – Rectal temp.
Rate of temp. fall/hour
Variation of body temperature
Conditions in which heat may be retained or increased.

15. “ Postmortem Caloricity”
Sun stroke and pontine haemorrhage, disturbed heat regulating mechanism.
Tetanus and strychnine poisoning, due to increase in heat production in the muscle.
Acute bacterial or viral infection, lobar pneumonia, typhoid fever, encephalitis, etc.
Intense asphyxial conditions- rise of temp by 2-3 c at death
“ Postmortem Caloricity”

16. The rate of cooling of the body is modified by the following conditions;
Age
Condition of the body
Mode of death
Surroundings
Environmental temperature

17. Postmortem Lividity
It means discolouration or staining of the skin and organs after death due to accumulation of fluid blood in the dependent parts of the body.
Post mortem staining/Hypostasis/Suggilation/ Vibices/ Livour mortis.
1- 3 hr. Starts
6-8 hr. Fixes.

18. Commencement of Lividity
Development of lividity
Fixation of lividity
Site of distribution
Pattern
Extent
Difference between lividity and bruise.

19. Medico-Legal Importance
It is a reliable sign of death
It gives the information about the position of the body at the time of death
Time since death can be estimated
Colour suggest the cause of death
Distribution of lividity may give the information about the manner of death

20. Changes in the Muscles Primary relaxation/ Flaccidity
Rigor mortis/Cadaveric rigidity
Secondary relaxation

21. Primary relaxation
Starts immediately after death with generalised relaxation of muscle tone:
Drop of lower Jaw
Eye balls lose their tension
Pupils are dilated
Joints are flabby
Smooth relaxation- incontinence of Urine and Faeces.

22. Rigor Mortis/ Cadaveric rigidity :
This phenomenon comes immediately after the muscles have lost the power of contractility and is irreversible changes in the muscles of the body, both voluntary and involuntary.
Myofibrils
Myosin and Actin
Adenosine Triphosphate – A.T.P.

23. Time of Onset :
Temperate climates – 3-6 hours
Tropical climates – 1-2 hours
Rigor mortis generally occurs when body is cold.
Not related to nerves action
Develops in paralysed limbs also
First appear in involuntary muscles
Last to be affected finger and toes muscles.

24. Duration : * Temperate climate – lasts for 2-3 days.
Tropical climate – 24 – 48 hours in winter
hours in summer
In general – 1-2 hours sets on
for , 12 hours develops
for hours maintaines
and after 12 hours passes of

25. Circumstances modifying the Onset and Duration of Rigor mortis.
Age- Rigor – Mortis is very rare in premature
infants.
Rigor –mortis is slow in adolescent
and healthy adults
Muscular conditon and activity before death.
Onset is slow and duration is longer in muscular and healthy body at rest.

26. Manner of death :
In wasting disease and great exhaustion- cholera, plague, typhoid, T.B. Cancer etc. the onset is early and disappears soon.
In diseases – Pneumonia, asphyxia and nervous conditions- onset is delayed Atmospheric condtions:
In dry and cold air-onset slow and lost for long time. Warm and moist air onset is rapid and duration short.

27. Conditions Simulating Rigor-Mortis
Heat Stiffening
Cold Stiffening
Cadaveric Spasm
Secondary Relaxation :
Muscles become soft and Flaccid
Do not respond to a mechnical and electrical stimulus.

28. Late Signs Of Death Decomposition / Putrefaction.
Adipocere formation / Saponification.
Mummification.

29. Decomposition / Putrefaction
Last stage in the resolution of the body,from the organic to the inorganic state, is a certain sign of death.
AUTOLYSIS
Rise of enzyme levels in the tissue cells after death.
Softening & liquefying of the body tissue.
Starts 3-4 hrs after death and continues for 2-3 days.

30. BACTERIAL ACTION
Action of bacterial enzymes on tissue components – carbohydrates/fat/proteins.
Bacterial growth – warmth,moisture are conditions favourable.
Clostridium welchii, streptococci, E coli, B proteus.

31. CHARACTERISTIC FEATURES
COLOUR CHANGES
Greenish discoloration of skin over caecum and flanks after death appears hrs.
Greenish to black discoloration- ‘Sulphmethahaemoglobin’ formed by H2S due to microorganisms in the large intestine.
Appears early in summer & delayed in winter.

32. Discoloration spreads- front of abdomen, external genitals, chest, neck, face, arms and legs – spreads whole body in hrs.
Discoloration of vessel walls due to pigmentation from decomposed blood over the shoulder and groin. Arborescent pattern- ‘Marbling’

33. GASES OF PUTRIFACTION
Development of gases under the skin and hollow viscera hrs hrs in solid viscera.
H2S, ammonia, phosphated hydrogen, CO2 and methane.
Causes pseudo rigidity, exerts pressure.
More gases accumulation, body floats in water.

34. PRESSURE EFFECTS OF PUTREFACTIVE GASES
Displaces the diaphragm upwards.
Discolored fluid and liquefied tissue mixes with gases producing froth.
Bloating of the features.
Shifting of the area of hypostasis.
Changes in skin, hair and wound.
Extrusion of fluid from the mouth and nose.
Emptying of the heart.
Changes in appearance of genitals.

35. APPEARANCE OF MAGGOTS
Flies lay eggs over the decomposed body- nose, mouth, vagina and anus in hrs.
After hrs eggs hatch into larvae or maggots, enter the body and destroy the tissues.
After 4-5 days develop into pupae.
After 7-8 days into adult fly.

36. OTHER SEQULAE
Fall of teeth
Separation of skull sutures
Liquefied brain matter oozes out.
‘Colliquative putrifaction’ – this process takes place between 7-14 days.

37. INTERNALLY
STOMACH
Dark red patches over the walls
Perforation due to autolysis
LIVER
Softens and flabby
Becomes spongy ‘Foamy liver’

38. Early putrefaction 24-48hrs
Larynx, trachea, brain of infants, stomach, intestines, spleen, omentum and mesentery, liver and adult brain.
Late putrefaction 2-3 weeks
Heart, lungs, kidneys, bladder, esophagus, pancreas, diaphragm, blood vessels, prostate, testis and non gravid uterus, ovaries.

39. FACTORS MODIFYING PUTREFACTION
EXTERNAL
Warmth and clothing
Putrefaction begins at 10°C and occurs rapidly at 37°C.
Freezing point – bacterial growth inhibited and putrefaction will not occur.
Clothing hastens putrefaction initially and protects against flies and insects.

40. Moisture
Help in rapid multiplication of organisms.
Bodies recovered from water if left in air, decomposes rapidly.
Air
1 week in air = 2 weeks in water = 8 weeks buried – ‘Casper dictum’

41. Manner of burial
In air tight coffins, very little change of body for long periods.
Without coffins, putrefaction is very rapid.
Bodies in deep graves putrefy very slow.
Bodies buried in lime, decomposition is retarded.
Bodies in sandy and porous soils are conducive to mummification.

42. INTERNAL FACTORS
Age and condition of the body
Sex
Mode of death

43. ADIPOCERE
Modification of the process of putrifaction in the dead body is (checked and is replaced) adipocere formation.
Hydrolisation of fatty tissue into fatty acids.
Bacterial fat splitting enzymes and moisture are essential – Lecithinase.
Composed of saturated fatty acids by palmitic, stearic, hydroxystearic, olic acids

44. Yellowish white, greasy wax with rancid smell.
It forms at any site where fatty tissue is present.
Time required, in summer-3 wks, in tropics-5 to 15 days.
M.L.I. – to establish the identity
- cause of death
- time since death
- place of death

45. MUMMIFICATION
It is a peculiar desiccation of a dead body where by its soft parts shrivel up but retain the natural appearance and the features of the body.
Rusty brown color, dry, leathery skin adherent to bones.
Internal organs get transformed into a thick brown mass.

46. Mummification occurs in bodies buried in shallow graves, in dry sandy soils.
Time – 3 months to 1-2 yrs
M.L.I. – Identification
- Cause of death
- Time since death
- Place of death

47. Time since death/ post mortem interval
Important clue for investigation of time.
It helps apprehend the person likely to be involved.
Point to be ascertained are;
-cooling of the body
-post mortem lividity
-rigor mortis
-decomposition changes

48. Contents of stomach and bowels
Contents of urinary bladder
Biochemical changes
Circumstantial evidence