5 Stages of Decomposition
Following death, the human body progresses through five basic stages of decomposition, fresh, bloat, active decay, advanced decay, dry/skeletal.
Terms in this set (5)
Begins immediately after death when the circulatory system stops functioning. The blood will settle with gravity creating lividity. After several hours the muscles will also begin to stiffen in a process known as rigor mortis. The body temperature will begin to acclimate to the environment. Cells will begin to break down and release enzymes during a process called autolysis which can cause blisters on the skin. The anaerobic organisms in the digestive tract will begin to multiply, producing acids and gases (the source of the bad odors).
The gases begin to build and will give the body a distended appearance. Gases and fluid will eventually escape through the natural orifices as the pressure builds. As the gastrointestinal bacteria multiply and can lead to a discoloration pattern seen in the skin. You may also see discoloration in the abdomen areas and on the skin overall as the process advances.
The body begins to lose much of it's fluids and mass (tissue) through purge and insect and/or vertebrate scavenging. During this phase you may see very large maggot masses and notice a considerable increase in foul odors.
Temperatures can either speed up (heat) or slow down (cold) how quickly a body reaches this phase. The body has very little body mass and soil staining of the surrounding soils is still evident. This soil staining (from body fluids) may actually kill some of the surrounding vegetation temporarily. Maggots will migrate away from the body to pupate and flies will cease laying eggs.
The timing of this stage varies widely by environment. If there is any skin left it will be leather-like and very tough. Mostly the body is reduced to bones and connective tissue. There is no biomass available for diverse insect colonization. Some beetles and adventitious insects may colonize a body for shelter or feeding on other insects and connective tissue. Over time the bones may "bleach" (turn white) with exposure to sunlight and eventually will begin to exhibit cracks after several years.