Putrefaction

Putrefaction is one stage in the decomposition of the body of a dead animal; it can be described as the decomposition of proteins, which results in the eventual breakdown of cohesion between tissues and liquification of most organs.

Description

The breakdown of proteins in a decomposing body is a spontaneously occurring process, though one which occurs at an increased rate as anaerobic microorganisms, already present in the animal's digestive tract when it was alive, consume and digest the proteins that comprise the body's cells. As cells and their proteins are digested, the body's tissues are left in a weakened state. Proteins are broken down into smaller components which are excreted by the bacteria. The excreted components, which include gases and amines like putrescine and cadaverine, are why a decomposing body has a putrid odor. The gases are initially constrained to the body cavities, but diffuse into other tissues and into the circulatory system. Once in the body's blood vessels, the gases can then spread to other parts of the body. The result is macroscopically visible bloating of the torso and then limbs. The increased internal pressure due to the increased volume of gas also helps to weaken and separate tissues. Eventually, some part of the body will rupture, releasing the gas. As the bacteria consume all available proteins, the process of decomposition progresses into the next stage: skeletonization.

The term decomposition is a generalized term for the overall process from the death of the individual until skeletonization of the body; putrefaction is only one stage of that process. Material that is subject to putrefaction is called putrescible.

Approximate timeline

2–3 days: Discoloration appears on the skin of the abdomen. The abdomen begins to swell, due to gas formation.

3–4 days: The discoloration spreads and discolored veins become visible.

5–6 days: The abdomen swells noticeably, and the skin blisters.

2 weeks: The abdomen is bloated; internal gas pressure nears maximum capacity.

3 weeks: Tissues have softened. Organs and cavities are bursting. The nails fall off.

4 weeks: Soft tissues begin to liquefy, and the face becomes unrecognizable.

The exact rate of putrefaction is dependent upon many factors, such as weather, exposure and location. Thus, refrigeration at a morgue or funeral home can retard the process, allowing for burial in three days or so following death without embalming. The rate increases dramatically in tropical climates.

Research

The University of Tennessee's Forensic Anthropology Facility is a body farm established in 1981 to study human putrefaction. Several others have been built in other locations since that time.

Other uses

In alchemy, putrefaction is the same as fermentation, whereby a substance is allowed to rot or decompose, undisturbed. In some cases, the commencement of the process is facilitated with a small sample of the desired material to act as a "seed".

See also

Cryopreservation

Maceration

Rancidification

Category:Alchemical processes Category:Food science