Decomposition

Decomposition involves two processes: autolysis and putrefaction. Autolysis is the breakdown of cells and organs from an aseptic chemical process caused by intracellular enzymes. Since it is a chemical process, it is accelerated by heat, slowed by cold, and stopped by freezing or the inactivation of enzymes by heat. Organs rich in enzymes will undergo autolysis faster than organs with lesser amounts of enzyme. Thus, the pancreas autolyzes before the heart.

The second form of decomposition, which to most individuals is synonymous with decomposition, is putrefaction. This is due to bacteria and fermentation. After death, the bacterial flora of the gastrointestinal tract invades the vascular system, spreading through­ out the body, producing putrefaction. This is accelerated in septic individuals because bacteria have already spread throughout the body prior to death.

When we talk about decomposition, we usually mean putrefaction. The onset of putrefaction depends on two main factors: the environ­ment and the body. In hot climates, the most important of these two factors is environment. Most authorities would give the following sequence of events in decomposition of bodies. First there is greenish discoloration of the lower quadrants of the abdomen, the right more than the left, usually in the first 24-36 h. This is followed by greenish discoloration of the head, neck, and shoulders swelling of the face due to bacterial gas formation and "marbling." Marbling is produced by hemolysis of blood in vessels with reaction of hemoglobin and hydro­gen sulfide and development of greenish black coloration along the vessels. The body soon undergoes generalized bloating followed by vesicle formation, skin slippage, and hair slippage. By this time, the body is a pale green to green-black color.

From Forensic Pathology by Dominick J. Di Maio, MD and Vincent J. M. Di Maio, MD