Post-Mortem Body Changes
Signs of Cadaveric Phenomena
These are biochemical and structural changes in tissues of a lifeless body, occurring passively due to environmental influences.
They have three different origins: chemical changes, abiotic phenomena, and putrefaction.
Chemical Changes in Cadaveric Tissues
Anoxia and progressive acidification of the internal environment with autolytic processes give rise to a series of signs of death.
Most significant are those due to changes in the internal environment’s reaction.
After death, progressive acidification of body fluids and tissues occurs. Techniques exist to verify the acidification of pH.
The simplest technique is the Lecha-Marzo method, investigating the pH in tear secretion with the aid of litmus paper.
Abiotic Cadaveric Phenomena
Cadaveric Lividity (Livor Mortis)
A phenomenon resulting from circulatory arrest, starting in the posterior neck in a supine body.
They begin 20-45 minutes after death as purple and red spots. These begin to coalesce after 1 hour and 45 minutes, occupying all dependent areas of the body at 10-12 hours post-mortem. It is an excellent late sign of death, usually fully established 12 to 15 hours after death.
Rigor Mortis
“a state of hardness, shrinkage and stiffness that occurs in the muscles after death”
Begins 3 to 6 hours after death in the muscles of the lower jaw and orbicularis oris, subsequently affecting the face, neck, chest, arms, trunk, and legs.
It is usually complete within 8-12 hours, reaches its maximum at 24 hours, and begins to disappear after 36-48 hours.
An absolutely reliable sign of death, although relatively late.
Cadaveric Phenomena Caused by Putrefaction
Action of microorganisms in the body.
Green Spot (Putrefaction)
A sign of late onset, appearing on average 36 hours after death.
Produced by the action of hydrogen sulfide generated during the putrefaction of hemoglobin and its breakdown products.
Appears in areas with the highest concentration of microorganisms (typically the lower right quadrant of the abdomen).
An absolutely true sign of death; its disadvantage is its late onset (24-48 hours).
Cadaveric Cooling (Algor Mortis)
The body temperature gradually decreases to match the environment.
From the moment of death, the body behaves like a hot object that no longer receives heat.
Period of Thermal Equilibrium
Cooling starts at the periphery and moves towards deeper layers.
Core cooling is achieved later.
Significant cooling does not occur until approximately 2 hours after death.
Distribution of cooling results.
After this apparent pause, cooling becomes noticeable, leading to a more regular progression.
Post-mortem Hyperthermia
Occurs when there has been an unusual increase in heat production, especially in deaths involving seizures or excessive bacterial activity.
Evolution of the Cooling Process
The cooling process begins with the feet, hands, and face, which become cold within 2 hours after death.
It then extends to the extremities, chest, and back.
Finally, the belly, armpits, and neck cool.
Deep abdominal organs retain heat for a long time, even up to 24 hours.
The body feels cool to the touch within 8 to 17 hours, more often between 10 to 12 hours after death.
Factors Affecting Cooling
Cause of Death: Chronic diseases and hemorrhage can lead to rapid cooling.