Putrefaction
Encyclopedia
Putrefaction is one of seven stages in the decomposition
of the body of a dead animal. It can be viewed, in broad terms, as the decomposition of protein
s, in a process that results in the eventual breakdown of cohesion between tissues and the liquefaction of most organs.
, already present in the animal's digestive tract when it was alive, consume and digest the proteins that comprise the creature's cells. As cells and their proteins are digested, the tissues of the body are left in a weakened state. Proteins are broken down into smaller components and these are excreted by the bacteria. The excreted components, which include gases and amine
s such as putrescine
and cadaverine
, give rise to the putrid odor associated with a decomposing body. The gases are initially constrained within the body cavities but diffuse though adjacent tissues and into the circulatory system
. Once within the blood vessels, the gases will then spread to other parts of the body. The result is macroscopically visible bloating of the torso and then the limbs. The increased internal pressure due to the increased volume of gas also helps to weaken and separate tissues. In the end 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 expression covering 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.
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.
'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.
, 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".
Decomposition
Decomposition is the process by which organic material is broken down into simpler forms of matter. The process is essential for recycling the finite matter that occupies physical space in the biome. Bodies of living organisms begin to decompose shortly after death...
of the body of a dead animal. It can be viewed, in broad terms, as the decomposition of protein
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
s, in a process that results in the eventual breakdown of cohesion between tissues and the liquefaction of most organs.
Description
In terms of thermodynamics, all organic tissue is a stored source of chemical energy and when not maintained by the constant biochemical efforts of the living organism it will break down into simpler products. The breakdown of proteins in a decomposing carcass is a spontaneous process but one that is accelerated as the anaerobic microorganismsAnaerobic organism
An anaerobic organism or anaerobe is any organism that does not require oxygen for growth. It could possibly react negatively and may even die if oxygen is present...
, already present in the animal's digestive tract when it was alive, consume and digest the proteins that comprise the creature's cells. As cells and their proteins are digested, the tissues of the body are left in a weakened state. Proteins are broken down into smaller components and these are excreted by the bacteria. The excreted components, which include gases and amine
Amine
Amines are organic compounds and functional groups that contain a basic nitrogen atom with a lone pair. Amines are derivatives of ammonia, wherein one or more hydrogen atoms have been replaced by a substituent such as an alkyl or aryl group. Important amines include amino acids, biogenic amines,...
s such as putrescine
Putrescine
Putrescine is a foul-smelling organic chemical compound NH24NH2 that is related to cadaverine; both are produced by the breakdown of amino acids in living and dead organisms and both are toxic in large doses...
and cadaverine
Cadaverine
Cadaverine is a foul-smelling compound produced by protein hydrolysis during putrefaction of animal tissue. Cadaverine is a toxic diamine with the formula NH25NH2, which is similar to putrescine...
, give rise to the putrid odor associated with a decomposing body. The gases are initially constrained within the body cavities but diffuse though adjacent tissues and into the circulatory system
Circulatory system
The circulatory system is an organ system that passes nutrients , gases, hormones, blood cells, etc...
. Once within the blood vessels, the gases will then spread to other parts of the body. The result is macroscopically visible bloating of the torso and then the limbs. The increased internal pressure due to the increased volume of gas also helps to weaken and separate tissues. In the end 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
Skeletonization (forensics)
In forensics, skeletonization refers to the complete decomposition of the non-bony tissues of a corpse, leading to a bare skeleton. In a temperate climate, it usually requires three weeks to several years for a body to completely decompose into a skeleton, depending on factors such as temperature,...
.
The term decomposition is a generalized expression covering 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 abdomenAbdomenIn vertebrates such as mammals the abdomen constitutes the part of the body between the thorax and pelvis. The region enclosed by the abdomen is termed the abdominal cavity...
. 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
Embalming
Embalming, in most modern cultures, is the art and science of temporarily preserving human remains to forestall decomposition and to make them suitable for public display at a funeral. The three goals of embalming are thus sanitization, presentation and preservation of a corpse to achieve this...
. The rate increases dramatically in tropical climates.
Research
The University of TennesseeUniversity of Tennessee
The University of Tennessee is a public land-grant university headquartered at Knoxville, Tennessee, United States...
's Forensic Anthropology Facility is a body farm
Body Farm
A body farm is a research facility where human decomposition can be studied in a variety of settings. The aim is to gain a better understanding of the decomposition process, permitting the development of techniques for extracting information from human remains...
established in 1981 to study human putrefaction. Several others have been built in other locations since that time.
Other uses
In alchemyAlchemy
Alchemy is an influential philosophical tradition whose early practitioners’ claims to profound powers were known from antiquity. The defining objectives of alchemy are varied; these include the creation of the fabled philosopher's stone possessing powers including the capability of turning base...
, putrefaction is the same as fermentation
Fermentation (biochemistry)
Fermentation is the process of extracting energy from the oxidation of organic compounds, such as carbohydrates, using an endogenous electron acceptor, which is usually an organic compound. In contrast, respiration is where electrons are donated to an exogenous electron acceptor, such as oxygen,...
, whereby a substance is allowed to rot
ROT
The aviation term ROT stands for rate one turn, also known as a standard rate turn. All aircraft must be able to perform a standard rate turn....
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
- CryopreservationCryopreservationCryopreservation is a process where cells or whole tissues are preserved by cooling to low sub-zero temperatures, such as 77 K or −196 °C . At these low temperatures, any biological activity, including the biochemical reactions that would lead to cell death, is effectively stopped...
- MacerationMaceration (bone)Maceration is a bone preparation technique whereby a clean skeleton is obtained from a vertebrate carcass by leaving it to decompose inside a closed container at near-constant temperature...
- RancidificationRancidificationRancidification is the chemical decomposition of fats, oils and other lipids . When these processes occur in food, undesirable odors and flavors can result. In some cases, however, the flavors can be desirable . In processed meats, these flavors are collectively known as "warmed over flavor"...