Cadaver

# Overview
A cadaver or corpse is a dead body. "Cadaver" is normally used as a more formal term for a body being used in medical training or research.

# Human decay
Different stages of decomposition can help determine how long a body has been dead.
The first stage is self digestion, also known as autolysis.  This happens when the cells break down the body into elements the cells can eat; this creates a liquid that gets between the layers of skin and makes the skin peel off. During this stage, flies (when present) start to lay eggs in the openings of the body: eyes, nostrils, mouth, ears, open wounds, and other orifices. Hatched larvae (maggots) subsequently get under the skin and start to eat the body.
The second stage of decomposition is bloating; bacteria in the gut begin to break down the tissues of the body, releasing gas that accumulates in the intestines, which becomes trapped due to the early collapse of the small intestine.  This bloating occurs largely in the abdomen, and sometimes in the mouth and genitals. The tongue may swell. This usually happens in about the second week of decomposition.  Gas accumulation and bloating will continue until the body is decomposed sufficiently for the gas to escape.
The third stage is putrefaction. It is the last and longest stage. Putrefaction is where the larger structures of the body break down, and tissues liquefy.  The digestive organs, the brain, and lungs are the first to disintegrate. Under normal conditions, the organs are unidentifiable after three weeks. The muscles can be eaten by bacteria or devoured by carnivorous animals.  Eventually, sometimes after several years, all that remains is the skeleton.

# Embalming
When a corpse is buried the body will still eventually decompose by the actions of anaerobic bacteria. In many countries, corpses buried in coffins are embalmed. An embalmer may clean and shave the face, fill the eye sockets with cotton to make them appear full, and suture the jaw together to keep it from hanging open. Embalming fluid is then pumped into the body via an artery (commonly carotid). This rehydrates the tissues and severely reduces the pace of decomposition.
Embalming is used to preserve the corpse temporarily, but may last for years.  In some societies, such as the United States, make-up is applied to the corpse to make the body presentable for public presentation.

# A brief history of cadavers
The methods of preserving cadavers, and their acquisition, have changed over the last 200 years. Criminals who were executed for their crimes were used as the first cadavers. The demand for cadavers increased when the number of criminals being executed decreased. Since corpses were in such high demand, some people decided to steal bodies from graves in order to keep the market supplied. From 1827 to 1828 in Scotland, murders were carried out, so that the bodies could be sold to medical schools for cash. These were known as the West Port murders. The Anatomy Act of 1832 was formed and passed because of the murders. Cadavers used to be used when they were fresh, but that did not always work out, and it was hard to keep them preserved. Preservation was needed in order to carry out classes and lessons about the human body. Glutaraldehyde was the first main chemical used for embalming and preserving the body. Glutaraldehyde leaves a yellow stain in the tissues, which can interfere with observation and research. Formaldehyde is the chemical that is used as the main embalming chemical now. It is a colorless solution that maintains the tissue in its life-like texture and can keep the body well preserved for up to six weeks.

# Abusive cadaver use
Human bodies and remains are being sold illegally all over the world without permission from deceased. At UCLA, Henry Reid and Ernest Nelson were found guilty of harvesting body parts and selling them to other companies from the Willed Body Program. In the case of Leigh Ajan, her mothers body was sent to the Tulane University for research on kidney and heart diseases. Not long after arriving at Tulane University, she was sent to a brokerage for bodies. This brokerage usually sells the bodies to the U.S. Army to be used for land mine tests. Along with the U.S. Army, body parts have been sold to other companies and people instead of being cremated or buried. In Annie Cheneys book she writes about bodies being sold from brokers to clients, such as scientists, pharmaceutical companies, and tissue banks. It is suspected that there are more cases of abuse gone undealt with or undiscovered, and more currently happening.

# Body snatching over the years
But cadavers have not always been treated with the same respect they are given today. Before modern science cadavers were stolen from graves,  relatives, and criminals to provide for science.
Herophilus, the father of anatomy, lived in 300 BC in Alexandria, Egypt. He was the first physician to dissect bodies. According to rumor, he dissected live criminals.
The tradition of dissecting criminals was carried up into the eighteenth and nineteenth century when anatomy schools became popular in England and Scotland. At that time, Christians believed in the literal raising from the dead. Because the souls of dissected bodies could not go to heaven, people rarely offered their bodies to science. The only cadavers available were criminals', and anatomists were portrayed as no better than an executioner.
Anatomy schools began to steal bodies from graves. "Grave robbers" were technically people who stole jewelry from the deceased, but stealing the dead body was not a crime. Some anatomy instructors encouraged this "body snatching". Students sometimes paid tuition in corpses or dug up bodies as late night pranks.
Some respected anatomy instructors dug up bodies themselves. The anatomist Thomas Sewell, who later became the personal physician for three U.S. presidents, was convicted in 1818 of digging up a corpse for dissection.
Anatomists would even dissect members of their own family. William Harvey, the man famous for discovering the circulatory system, was so dedicated he dissected his father and sister.
By 1828 anatomists were paying others to do the digging. At that time, London anatomy schools employed ten full time body snatchers and about two hundred part timer workers during the dissection season. This period ran from October to May, when the winter cold slowed down the decomposition of the bodies. A crew of six or seven could dig up about 312 bodies. The average body snatcher made about 1,000 dollars a year, ten times more than the average unskilled laborer of that time period, with summers off.
The poor were most vulnerable, because they could not afford coffins to keep the body snatchers out.
Disposing of the dissected body was difficult, and rumors have appeared about how the anatomist might have managed. They could have buried the cadavers out behind the school. Perhaps they gave the bodies to zoo keepers or fed the bodies to vultures kept specifically for this purpose. One colorful story has the anatomists making  soap and candles to give away as gifts.
Stories appeared of people murdering for the money they could make off cadaver sales. Two of the most famous are that of Burke and Hare, and that of Bishop, May, and Williams.
- Burke and Hare  Burke and Hare ran a boardinghouse. When one of their tenants died, they brought him to Alexander Monros anatomy rooms in Edinburgh where they were paid seven pounds for the body. Realizing the possible profit, they supposedly murdered sixteen people over the next nine months and sold their bodies to different anatomists. They were eventually caught. Burke was found guilty, hanged, and publicly dissected. Hare escaped England where he worked as a plasterers apprentice until they found out who he was and threw him in a lime pit. He was blinded and begged on the streets for the rest of his life.
- Bishop, May and Williams  These body snatchers also killed three boys, ages ten, eleven and fourteen years old. The anatomist that they sold the cadavers to was suspicious. To delay their departure the anatomist said he needed to break a fifty pound note. He sent for the police who arrested the men. In Bishop's confession he stated, I have followed the course of obtaining a lively hood as a body snatcher for twelve years, and have obtained and sold, I think from 500 to 1,000 bodies
By the 1890s body snatching was less common and by the 20th century it had all but disappeared. Embalming and preservation of cadavers became more advanced and education in medical schools improved. Students no longer had to quickly dissect bodies before they decomposed.  These dissections were orderly and complete. Improvements in medical school, including a graded curriculum, meant doctors were better educated. The medical profession received new esteem by diagnosing and healing more people. With that respect came a larger supply of cadavers, making body snatching almost non-existent.