1
Q
What are Post-Mortem Changes?
A
- Cooling of the body
- Postmortem Hypostasis “Lividity” or “Livor-Mortis”
- Postmortem Rigidity or “Rigor Mortis “ “Stiffness of Death “
- Putrefaction or Decomposition
2
Q
Def of Post-Mortem Cooling
A
- Defined as gradual cooling of dead body until it comes in equilibrium with surrounding temperature.
3
Q
Rate of Post-Mortem Cooling
A
- The average rate of heat loss is about 1-1.5°C/h
- Rate of cooling is not uniform
4
Q
Mechanism of Post-Mortem Cooling
A
- During life, there is balance between heat production and heat loss.
- After death, heat production stops and body loses heat.
5
Q
when does dead body attain environmental temperature?
A
- Dead body attains environmental temperature “external surface cooling” in about 16-20hs from death.
6
Q
what are factors that affect Post-Mortem Cooling?
A
- Environmental temperature (Major factor)
- Media of disposal
- Mode and cause of death
7
Q
how does media of disposal affect Post-Mortem Cooling?
A
In case of drowning in running water
- Rate of heat loss is double that in the air
(2-3° C /h).
7
Q
How does environmental temperature affect Post-Mortem Cooling?
A
- The dead body cools rapidly, when difference between environmental temperature and that of corpses is great as in the winter.
8
Q
What types of deaths cause slow Post-Mortem Cooling?
A
occurs in deaths due to
* Infectious diseases
* Heat stroke (fever).
9
Q
What types of deaths cause fast Post-Mortem Cooling?
A
occurs in deaths due to
- Long wasting illness as T.B
- or shock.
10
Q
MLI of Post-Mortem Cooling
A
- It is a sign of death.
- It helps in rough estimation of time of death.
11
Q
what are other names for Postmortem Hypostasis?
A
“Lividity” or “Livor-Mortis”
12
Q
Def of Postmortem Hypostasis
A
- It is bluish or purplish discoloration or staining of most dependent parts of body skin and internal organs after death.
- It is called “Postmortem staining” or “Darkening of death”.
13
Q
Mechanism of Postmortem Hypostasis
A
14
Q
Onset of Postmortem Hypostasis
A
- Usually begins immediately after death
15
Q
Shape of Postmortem Hypostasis
A
- Begins as small mottled patches on dependent parts of body within 1-3 hs.
- Mottled patches coalesce with each other to form uniformly stained large areas
16
Q
Color of Postmortem Hypostasis
A
Has same color as blood that can be mistaken for bruises.
17
Q
Blanching of Postmortem Hypostasis
A
18
Q
Fixation of Postmortem Hypostasis
A
19
Q
Absence of Postmortem Hypostasis
A
- Hypostasis does not develop over areas of contact flattening
- This phenomenon is known as contact pallor as vessels in these areas remain pressurized and the blood is compressed out.
20
Q
Postmortem Hypostasis as a sign of death
A
- Hypostasis is a sure sign of death
- it is one of the best proofs for somatic death.
20
Q
MLI of Postmortem Hypostasis
A
- A sign of Death
- Important in Determination of Time passed since death
- Important in determination of Cause of death
21
Q
Importance of Postmortem Hypostasis in detection of time passed since death
A
- It helps to estimate time passed since death from
formation, extension and fixation of postmortem staining. - There is early onset hypostasis in case of a person who died after. prolonged recumbent position
22
Q
Importance of Postmortem Hypostasis in detection of casue of death
A
It gives an idea about the cause of death
- From its position
- From its color
23
**Postmortem Hypostasis** in cases of hanging
The site of distribution and pattern of lividity depend upon the position of body after death
- Hypostasis is observed over dependent (Lower limbs, External genitalia, Distal parts of forearms and hands)
24
**Postmortem Hypostasis** in cases of drowning
24
**Postmortem Hypostasis** in natural death
Bluish purple
25
**Postmortem Hypostasis** in hemorrhage & Severe anemia
Very faint
26
**Postmortem Hypostasis** in asphyxia
Deep blue
27
**Postmortem Hypostasis** in cases of CO Poisoning
Red color
28
Color of **Postmortem Hypostasis** and what it indicates
29
DDx of **Postmortem Hypostasis**
In certain cases, isolated patches of lividity remain separate from large areas of lividity and may resemble antemortem bruises.
30
Compare between PM lividity & AM Bruises
31
what is another name for **Postmortem Rigidity**?
"Rigor Mortis " or "Stiffness of Death
32
Def of **Postmortem Rigidity**
- It is a condition of progressive stiffening and rigidity of both voluntary and involuntary muscles,
33
what precedes and follows **Postmortem Rigidity**?
- Preceded by period of primary flaccidity
- Followed by secondary flaccidity.
34
Mechanism of **Postmortem Rigidity**
35
Timeline of **Postmortem Rigidity**
- 2 hours after death
- 12 hours after death
- 48 hours after death
36
**Postmortem Rigidity** 2 hours after death
- Rigor mortis starts to appear 2 hours after death in small muscles then spreads from above downwards.
- It affects firstly muscles of eye lids, and then jaw, muscles of face, neck and trunk, followed by muscles of upper limbs and then lower limbs.
37
**Postmortem Rigidity** 12 hours after death
Rigor mortis takes 12 hours to be completed all over body "Fixed body".
38
**Postmortem Rigidity** 48 hours after death
- Rigor mortis disappears completely in about 36-48 hours after death.
- The rigid muscles start to soften gradually in same order of their occurrence
39
testing of **Postmortem Rigidity**
40
what are factors affecting **Postmortem Rigidity**?
41
MLI of **Postmortem Rigidity**
- Rigor mortis helps to estimate time passed since death by marching of rigor.
- Rigor mortis can give information about position of the body at time of death.
42
Site of **Cadaveric Spasm**
- It is usually limited to a single group of voluntary muscles
- frequently involves the hands
42
Def of **Cadaveric Spasm**
- It is stiffening of specific group of voluntary muscles, immediately after death, without being precedod by stage of primary flaccidity.
43
Examples of **Cadaveric Spasm**
44
DDx of **Cadaveric Spasm**
45
Def of **Putrefaction or Decomposition**
- It is a biological process caused by growth of bacteria on organic matter of dead body transforming it into inorganic state.
46
Mechanism of **Putrefaction or Decomposition**
47
Onset of **Putrefaction or Decomposition**
Putrefaction starts after
- 24hs after death in summer
- 48hs in winter.
48
External signs of **Putrefaction or Decomposition**
Y3R2 - Forensic ⚠️
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