Post Mortem Changes.

 

Rigor mortis is the postmortem stiffening of the body’s muscles. It may or may not involve some degree of actual shortening of the muscles. In most cases, rigor mortis begins within 1-2 hours after death; it begins to pass after 24 hours

 

Livor mortis is the purple-red coloration that appears on dependent portions of the body other than areas exposed to pressure after the heart ceases to beat. It results from the settling of the blood under the force of gravity

 

Tardieu spots are petechiae and purpuric hemorrhages that develop in areas of dependency secondary to the rupture of degenerating vessels under the influence of increased pressure from gravity

Algor mortis is the process by which the body cools after death. Cooling takes place only if the ambient temperature is cooler than the body temperature at the time of death.

Tache noire is the dark, red-brown stripe that develops horizontally across the eyes when the eyelids are not closed after death. It is a drying artifact that may mimic trauma

 

Decomposition is the postmortem process of endogenous autolysis and putrefaction from external and primarily internal bacterial sources.

Maceration is an autolytic postmortem process that occurs in intrauterine deaths. It is caused by endogenous enzymes; putrefactive bacteria are not a factor.

Marbling may develop with the delineation of the vasculature as a result of the reaction of hydrogen sulfide produced by bacteria with hemoglobin from the lysis of erythrocytes, as shown below. Bloating of the body occurs as a result of bacterial gas production; in intemperate conditions, bloating occurs over a period of 2–3 days. Bloating causes distortion of both the body and face.

Degloving of the skin of the palms and soles typically occurs during decomposition, as well as in cases involving thermal exposure (ie, fires) and immersions,The epidermis commonly retains enough ridge detail to allow fingerprints to be obtained, which assists in the identification of the decedent.

 

Adipocere formation typically occurs in bodies submerged in water or in warm, humid environments. The tissues are converted into a waxy, pasty material as a result of the reaction of clostridial enzymes with tissue fatty acids.