1. Pallor of the skin.

2. Cooling of the body.

3. Hypostasis or Lividity "Livor-Mortis ".

4. Rigidity or "Rigor Mortis”.

5. Putrefaction.

Cooling of the body

It occurs in cold weather.

Heat production & heat loss during life and after death.

Measurement of the dead body temperature.

The average rate of heat loss:

1-1.5 oC/ hour.

Cooling of the bodyCooling of the body

Factors affecting rate of cooling:

1. Temperature either environmental or body

temperature .

2. The size of the body.

3. Clothing & coverings.

4. Movement & humidity of the air.

5. Immersion in water.

It means discoloration or staining of the

skin of the most dependent parts of the body

and internal organs after death.

It is due to…………..

Hypostasis Hypostasis

or Lividity "Livor-Mortis " or Lividity "Livor-Mortis "

The staining is of the same colour of the

blood.

Hypostasis does not develop over areas of

contact flattening or compressed parts (i.e.

the pressure mark of the waist band), because

the capillaries and veins are occluded by the

pressure.

Blanching test for confirmation of hypostasis

Post-mortem hypostasis or Livor mortis. The white areas are due to pressure upon the ground.

The trunk of a body viewed from the side.

Normal distribution of P.M. Lividity in a body which lay on its back after death.

Hypostasis affected by simple pressure on the skin from tight clothing “ marks of the cup and strap of a bra seen over the chest.

Onset:

1. Occurrence (at the moment of death).

2. Appearance (1/2 – 1 hr.).

3. Well developed (4 – 8 hrs.)

4. Fixation (8-12 hrs).

M.L.I. of Hypostasis:

1. It is a sure sign of death, it is one of the best

proofs for somatic death.

2. It helps to estimate the time passed

since death: Early onset of hypostasis.

Delayed hypostasis (completed within 8-12

hour).

3. It gives information about the position of the

body. Changes of position after death lead to

changes in the site of lividity, so long as the

blood is still fluid.

Before fixation.

After fixation.

Ventral distribution of P.M. lividity with the deceased lying prone on the bed.

Persistence of ventral distrbution of P.M.lividity after the autopsy with the body in the supine position.

4- It gives an idea about the cause of death:

a. From its extent, ill defined in haemorrhage and

marked in asphyxia.

b. From its site as it is usually in the back in natural

death, in the lower limbs in hanging; & in the head &

upper parts of the body in drowning.

c. From its colour:

The lividity is better appreciated in fair-

skinned persons than in dark ones.

The colour of lividity depends upon the

colour of blood and the mode of death:

1. Light violet (a purple or reddish-purple ) in natural death.2. Very faint in deaths from haemorrhage or severe anaemia.3. Deep blue in asphyxia.

4. Bright pink in deaths due to exposure to severe cold, in bodies refrigerated very soon after death.

5. Cherry-red in CO poisoning.6. Cyanide poisoning results in lividity which is described by different

authors as pink, bright scarlet, and violet. 7. A pink colour at the sides of bodies exposed to the air, but not, as

rule, at the back or other areas which are close to the ground.8. Chocolate brown in cases where methaemoglobin is formed in the

blood during life (e.g. potassium chlorate, nitrates, and aniline poisoning) .

Normal distribution of P.M. Lividity in a body which lay on its back after death.

Cherry-red in cyanide poisoning

Crimson-red in CO poisoning

Deep blue in a woman hanged herself. Apparent marks of clothing which is seen on the arms and around the waist.

Postmortem lividityPostmortem lividity Antemortem Antemortem bruises bruises

Site Site .. On the dependent On the dependent parts. parts.

Anywhere at Anywhere at the site of the site of traumatrauma

Colour Colour Uniform colour and Uniform colour and according to the according to the cause of death e.g. cause of death e.g. violet in natural violet in natural deathdeath

.. Different Different colourscolours..

MarginMarginMerges with the Merges with the surrounding area. surrounding area.

Clear and Clear and definedefine..

Postmortem Postmortem lividitylividity

Antemortem Antemortem bruises bruises

Swelling Swelling No swellingNo swelling.. Swelling of the Swelling of the affected areaaffected area..

Abrasions Abrasions No abrasionsNo abrasions.. May be presentMay be present..

Cut incision Cut incision on the site on the site

- Small amount - Small amount of blood of blood oozing from oozing from the severed the severed capillaries.capillaries.

- - The blood The blood can be easily can be easily washed washed awayaway..

- Extra vasated - Extra vasated blood in the blood in the surrounding surrounding tissues.tissues.

-- The blood can The blood can not be washed not be washed easilyeasily..

Postmortem Postmortem lividitylividity

Antemortem Antemortem bruises bruises

MicroscopicaMicroscopicall

examinationexamination

Blood Blood elements are elements are found within found within the vessels.the vessels.

There is There is evidence of evidence of infiltration infiltration (blood (blood elements are elements are found found outside the outside the vessels).vessels).

Antemortem bruises. Patch of P.M. lividity.

It is a state of progressive muscular rigidity

replacing the condition of primary flaccidity and

affecting all muscles of the body i.e. voluntary and

involuntary.

Postmortem Rigidity Postmortem Rigidity

"Rigor Mortis”"Rigor Mortis”

Mechanism:

ATP

pH: 6

Onset:

It starts to appear 2 hours after death in the small muscles

of the eyelids, lower jaw and neck, followed by the limbs,

involving first the small distal joints of the hands and feet and

then the larger proximal joints of the elbows, knees and the

shoulders and hips.

It takes 12 hours to be completed all over the body.

It disappears completely in about 18-24 hours after death.

M.L.I. of Rigor Mortis:

1. It is a sure sign of death.

2. It helps to estimate the time passed since

death.

3. Preservation of the position of the body; as

agonists &antagonists undergo rigidity in the

same degree (without shortening of the

muscle)

4. Suggestion of the cause of death; as it is

rapid in onset in cases of convulsions, as

tetanus and strychnine poisoning, in

individuals who have been exhausted or

starved before death, the glycogen stores in

muscle are low, so that rigor may develop

rapidly.

Senile person

Muscular activity before death

Rigor Mortis

Rigor Mortis

1- Cadaveric Spasm.

2- Cold Stiffness.

3- Heat Stiffness.

This is a condition characterized by

stiffening of one group of the voluntary muscles,

immediately after death, without being

preceded by the stage of primary flaccidity.

Cadaveric SpasmCadaveric Spasm

Conditions necessary for the development of cadaveric spasm are:

1- Extreme rapid occurrence of somatic death.

2- Great emotional stress at the moment of death.

3- The affected group of muscles must be in physical

activity at the time of death.

Mechanism:

The exact mechanism is not known.

This condition occurs in cases of extreme nervous tension such as:

Some suicidal cases.

Some accidental cases.

Some homicidal cases.

Cadaveric Spasm. This victim grasped at some ivy as he fell into water.

Cadaveric Spasm

M.L.I. of Cadaveric Spasm:1. It indicates sudden death associated with

great emotional tension.

2. It indicates the muscles in physical activity at

the time of death.

3. It indicates the nature of death, whether

suicidal, homicidal or accidental.

The main differences between rigor mortis and cadaveric spasm are:

Rigor MortisRigor Mortis Cadaveric SpasmCadaveric Spasm

1.1.It occurs in all It occurs in all deathsdeaths..

In some cases, and In some cases, and a certain condition a certain condition is necessary for its is necessary for its onset (severe onset (severe nervous tensio)nervous tensio)..

2.2.It is preceded by It is preceded by primary primary flaccidity.flaccidity.

Absent primary Absent primary flaccidity.flaccidity.

3.3.It starts 2 hours It starts 2 hours after deathafter death..

It occurs at the It occurs at the moment of death.moment of death.

Rigor MortisRigor Mortis Cadaveric SpasmCadaveric Spasm

4.4.Both voluntary Both voluntary and involuntary and involuntary muscles are muscles are affected.affected.

Certain group of Certain group of voluntary muscles voluntary muscles only are affected.only are affected.

5.5.It occurs due to It occurs due to depletion of depletion of ATPase enzyme.ATPase enzyme.

The exact The exact mechanism is not mechanism is not yet known.yet known.

N.B.N.B.:: In cadaveric spasm, very great In cadaveric spasm, very great

force is necessary to breakdown the force is necessary to breakdown the

stiffness of the muscles.stiffness of the muscles.

When the body is rapidly frozen after

death, it retains the position in which it

was lying due to frozen body fluids.

Cold Stiffness:Cold Stiffness:

It is found in bodies that have been

subjected to heat (burn) before death.

Heat StiffnessHeat Stiffness ::

Muscular states following death:

The different muscular states which the body undergoes between somatic death and the onset of putrefaction are:

1- Primary flaccidity.

2- Rigor mortis.

3- Secondary flaccidity.

Putrefaction or Decomposition

It is the last stage in the resolution of the body from the organic to the inorganic state. Mechanism:

Bacterial action

HaemolysiHaemolysis of bloods of blood

Gas Gas formatioformatio

nn

SofteninSoftening of g of

tissuestissues

Onset of putrefaction:

It starts after one day in summer &

two days in winter.

M.L.I. of Putrefaction:

1. It helps to suspect the cause of death:

- Rapidly in

- Delayed in

2. Estimation of the time passed since death as follows:

In winterIn winter

1- Two days after death:

Greenish discoloration of the right iliac

region with arborisation of the vessels or

marbling of the skin.

2- One week after death:

•Greenish discoloration of the whole skin with

bullies.

•Distension of the abdomen

•The face is swollen, discoloured with thick

dark froth on the mouth and nostrils

3- Two weeks after death:

• Peeling of the skin.

• Rupture of the abdomen.

• The viscera are liquefied and precipitated to

the ground.

• Eggs of flies will now become larvae.

4- Six months after death:

All tissues are transformed into liquid

substance which percolates to the ground; so

leaving nothing except bones attached by

ligaments.

5- After 1 year:

Ligaments also disappear leaving separate

bones.

Putrefactive gases:

Early decomposition “Distended veins over forehead &shoulder.”

Bloating and discoloration of the skin due to the generation of gases in decomposition.

Protrusion of tongue and distortion of features.

Putrefaction after 1 week .

Peeling of the skin of the hand.

Peeling of the skin of the feet

Moderately advanced decomposition “distortion, swelling of the features, swelling of the eye balls & shedding of the skin”.

Moderately severe decomposition “Blackening &extensive shedding of the skin of the rt. Side of chest & abdomen”.

Six months after death.

It takes half the previously mentioned

times.

In summerIn summer

Conditions Replacing Putrefaction

1. Adipocere formation.

2. Mummification.

3. Maceration.

It is a modification of the process of

putrefaction.

Adipocere Formation (Saponification)Adipocere Formation (Saponification)

Mechanism:

Body fat warm , moist, anaerobic lead to endogenous bacteria

Hydrolysis & Hydrogenation

Fatty Acids

Inhibit putrefactive bacteria

Characters:.........1. The transformation of fatty tissues into a

yellowish-white, greasy, (but friable when dry), wax-like substance.

2. Production a penetrating ammoniacal odour is emitted during the early stages and the smell is very persistent. Then, a sweetish rancid odour. when its formation is complete.

3. It floats on water, and dissolves in hot

alcohol and ether.

4. When heated it melts and then burns with a

yellow flame.

5. Ordinarily it will remain unchanged for

years.

Time:

> 3 weeks 6 months for extensive

adipocere.

Adipocere Formation in buried infant. The body fat has been converted into brittle waxy material, which form a shell around the skeleton.

It is a modification of the process of

putrefaction.

MummificationMummification

Characters:1. Dehydration or desiccation of the tissues.

2. The body shrivels & is converted into a leathery or parchment-like mass of skin & tendons surrounding

the bone.

3. The internal organs are often decomposed but may be preserved.

4. Skin shrinkage may produce large artifactual splits mimicking injuries. These are particularly seen in the

groins, around the neck & the armpits

Mechanism:

It is a slow drying of the body fluid by

evaporation, especially when there are air

currents e.g., death in desert.

Advanced mummification in a discarded new-born infant. The back was arched .

Artificial Mummification in Ancient Egypt.

Artificial Mummification in Ancient Egypt.

Artificial Mummification in Ancient Egypt.

Maceration It is a temporary state replacing

putrefaction due to absence of organisms.

Mechanism:

Aseptic autolysis

Time for development:

One week

Characters:

1. The body is soft & extremely flaccid.2. Flattened head & over-riding with undue

mobility of the skull. 3. The limbs may be readily separated from the

body. 4. Large moist skin bullae which rupture to

disclose a lacerated dark reddish-brown skin with greasy sensation.

5. Rancid smell. 6. No gas formation.

N.B:The condition can be diagnosed by an

X-ray film to the pregnant female when in

doubt about the occurrence of intra-uterine

foetal death.

Maceration of the feotus

Macerated forearm of a still born foetus.

Time Passed Since Death

Postmortem-Interval (PMI)

Time Passed Since Death Postmortem-Interval (PMI)

1- Rate of cooling of the dead body.

2- Conductivity of tissues to electric current.

3- Extent of postmortem lividity.

4- Distribution of rigor mortis.

5- Extent of putrefaction or other replacing conditions.

6- Entomology of the dead body (Fauna of Cadaver):

Green Metallic Musca Domestica

7. From some “histological & biochemical changes”, in

the liver cells, C.S.F. & blood due to enzymatic

action.

8. From the state of the “gastric contents”, as the

emptying time are 3 hours. This necessitates

knowing the time of the last meal before death.

Animal cadaver

larvae