Post-mortem decomposition showing varying degrees of putrefactive changes in the face, trunk and extremities. The image shows the contrast sometimes seen between one part of the body and another, as the right leg and lower left side of the trunk are only slightly affected. The face, neck and hands are swollen with gas.
Decomposition, or putrefaction, is a combination of two processes: autolysis and bacterial action. Autolysis is the breakdown of cells and organs through an aseptic chemical process caused by intracellular enzymes. Because it is a chemical process, it is accelerated by heat, slowed by cold, and stopped by freezing. Bacterial action results in the conversion of soft tissues in the body to liquids and gases. The chemicals produced as a result of putrefaction are cadaverine and putrescine, hydrogen sulfide and other sulfides, which generate a horrible smell.