1. Presented by - b.boot Beta Particle
Post-Mortem changes
Presented by - b.boot Beta Particle

2. Post-Mortem Changes Seminar Outline Death Rigor Mortis
Livor Mortis/ Hypostasis
Algor Mortis/ Body Cooling
Decomposition

3. Death Cessation of the function of 3 systems: Types of Death:
CVS, RS, CNS
Types of Death:
Cellular death
cells no longer functioning or have metabolic activities or aerobic respiration.
Different tissue die at different rate; cerebral cortex tolerate only few minutes of anoxia while connective tissue and muscles may survive longer (for hours).
Somatic Death
the person is irreversibly unconscious, not aware of surrounding environment and he is unable to appreciate sensory stimuli or initiate any voluntary movement
Reflex nervous activity may persist and circulatory and respiratory function continue either spontaneously or with artificial support.
Somatic death= brain death = vegetative state
(all tissue and cells of the body are alive and functioning except for those damaged in the CNS)

4. Brain Dead

5. Indications of Death Indications of death: Unconsciousness
Loss of all reflexes
No reaction to painful stimuli
Muscular flaccidity
Cessation of heart beat and respiratory movement
Eye signs:
loss of corneal and light reflexes
Mid dilated position of the pupils
Irregular size and shape of the pupils
Eyelids usually closed incompletely
Tache noire: where the sclera remains exposed, two triangles of discoloration appear at each side of the cornea, either brown or black.

6. Tache Noire

7. Apparent Death a state that mimics death, occurs in: Electrocution
Hypothermia
Sun stroke
Drowning
Drug over dose (barbiturates)
Head injury

8. Medico-Legal Importance of Death Diagnosis
Detect cause of death
Know time of death
Social reasons
Organ donation
Apparent death
Statistical reasons
Heritage reasons

9. Rigor Mortis
One of the recognizable signs of death that is caused by a chemical change in the muscles after death, causing the limbs of the corpse to become stiff and difficult to move or manipulate.
Death cessation of respiration depletion of oxygen used in the making of ATP ATP no longer provided to operate the SERCA pumps in the membrane of the sarcoplasmic reticulum, which pump calcium ions into the terminal cisternae Calcium ions diffuse from the terminal cisternae and extracellular fluid to the sarcomere  Ca binds with troponin  crossbridging between myosin and actin proteins.
Unlike normal muscle contractions, the body is unable to complete the cycle and release the coupling between the myosin and actin, creating a perpetual state of muscular contraction, until the breakdown of muscle tissue by digestive enzymes during decomposition.
RM initiated when the ATP concentration falls to 85% of normal

10. Rigor Mortis (cont’d) Sequence: Primary muscular flaccidity
Generalized muscular stiffness
Secondary muscular flaccidity
RM starts to develop about 2-3 hrs after death
Usually it’s first detected in smaller muscle groups such as those around the eyes, mouth, jaw & fingers.
It resolves in the same order in which it develops.
It concludes around hrs after death

11. Factors affecting timing of RM
Environmental temperature:
Cold and wet  onset slow, duration longer
Hot and dry  onset fast, duration shorter
Muscular activity before death:
muscles healthy and robust, at rest before death  slow onset, duration longer
muscles exhausted/ fatigued  onset rapid, esp in those limbs being used (eg in someone running at time of death, lower limbs develop RM faster than upper limbs)
increase activity (convulsions, electrocution, lightning)  rapid onset & short duration
Age:
extremes of age  rapid onset
Health:
Cause of death:
asphyxia, pneumonia, nervous de’s with muscle paralysis & dehydration  slow onset
septicemia & poisoning  rapid onset, may even be absent, esp in limbs affected by septicimia
emaciated or died of wasting disease  rapid onset, short duration

12. RM: time estimation Warm Flaccid Death < 3 hrs Stiff 3-8 hrs Cold

13. Rigor Mortis (cont’d) RM in Iris: RM in the Heart:
Antemortem constriction or dilation modified
May affect the eyes unequal, making the pupils unequal
RM in the Heart:
Contracted, stiff LV may be mistaken for LV hypertrophy
RM in Dartos muscle of scrotum:
Rigor in Dartos constricts testes and epididymis expulsion of semen
Contraction of seminal vesicles and prostate
Postmortem expulsion of semen
RM in Erector Pilli muscles attached to hair follicles:
Goose bumps, hair stands up

14. Rigor Mortis

15. Cadaveric Spasm Cadaveric spasm
also known as instantaneous rigor, cataleptic rigidity, or instantaneous rigidity
rare form of muscular stiffening that occurs at the moment of death, persists into the period of rigor mortis and can be mistaken for rigor mortis
the cause is unknown, but usually associated with violent deaths happening with intense emotion
may affect all muscles in the body, but typically only groups, such as the forearms, or hands
seen in cases of drowning victims when grass, weeds, roots or other materials are clutched, and provides proof of life at the time of entry into the water.
often demonstrates the last activity one did prior to death and is therefore significant in forensic investigations, e.g. clinging on a knife tightly

16. Rigor Mortis vs. Cadaveric Spasm
Onset delayed after death (2-3 hrs)
Duration approx hrs
Onset is instantaneous
Duration is a few hours, until it is replaced by rigor mortis
Intensity comparatively moderate
Intensity comparatively very strong
Mechanism of formation: breakdown of ATP below critical level
Mechanism of formation unknown, but predisposing factors: Excitement, fear, fatigue, exhaustion, nervous tension, contraction of M’s at time of death
All muscles of the body are affected gradually.
Selected muscles, which were in a state of contraction at the time of death, are affected.

17. Cadaveric spasm in a drowning victim: had grass from the river bank firmly clutched in the hand
Victim of suicide: The cadaveric spasm has maintained the position of his arms after the shotgun has been removed

18. Conditions Mistaken as RM
Heat stiffness:
Exposure of a body to intense heat (burning, high voltage electrocution, etc) coagulation of muscular proteins  muscular shortening
Cold stiffness:
Exposure of the body to extreme cold (<-5⁰C) solidification of subcutaneous fat and muscles, freezing of synovial fluid in joints
Rigor mortis halted until thawing occurs, after which it develops very rapidly

19. Medicolegal Importance of RM
Time estimation
Cause of death
Know position
Sure sign of death