Cadaver
A cadaver, often known as a corpse, is a dead human body. Cadavers are used by medical students, physicians and other scientists to study anatomy, identify disease sites, determine causes of death, and provide tissue to repair a defect in a living human being. Students in medical school study and dissect cadavers as a part of their education. Others who study cadavers include archaeologists and arts students. In addition, a cadaver may be used in the development and evaluation of surgical instruments.
The term cadaver is used in courts of law to refer to a dead body, as well as by recovery teams searching for bodies in natural disasters. The word comes from the Latin word cadere. Related terms include cadaverous and cadaveric spasm. A cadaver graft is the grafting of tissue from a dead body onto a living human to repair a defect or disfigurement. Cadavers can be observed for their stages of decomposition, helping to determine how long a body has been dead.
Cadavers have been used in art to depict the human body in paintings and drawings more accurately.
Human decay
Observation of the various stages of decomposition can help determine how long a body has been dead.Stages of decomposition
- The first stage is autolysis, more commonly known as self-digestion, during which the body's cells are destroyed through the action of their own digestive enzymes. However, these enzymes are released into the cells because of cessation of the active processes in the cells, not as an active process. In other words, though autolysis resembles the active process of digestion of nutrients by live cells, the dead cells are not actively digesting themselves as is often claimed in popular literature and as the synonym of autolysis – self-digestion – seems to imply. As a result of autolysis, liquid is created that seeps between the layers of skin and results in peeling of the skin. During this stage, flies begin to lay eggs in the openings of the body: eyes, nostrils, mouth, ears, open wounds, and other orifices. Hatched larvae of blowflies subsequently get under the skin and begin to consume 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 because of the early collapse of the small intestine. This bloating occurs largely in the abdomen, and sometimes in the mouth, tongue, and genitals. This usually happens around 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 final and longest stage. Putrefaction is where the larger structures of the body break down, and tissues liquefy. The digestive organs, brain, and lungs are the first to disintegrate. Under normal conditions, the organs are unidentifiable after three weeks. The muscles may be eaten by bacteria or devoured by animals. Eventually, sometimes after several years, all that remains is the skeleton. In acid-rich soils, the skeleton will eventually dissolve into its base chemicals.
History
The history of the use of cadavers is filled with controversy, scientific advancements, and new discoveries. Beginning in the 3rd century ancient Greece two physicians by the name of Herophilus of Chalcedon and Erasistratus of Ceos practiced the dissection of cadavers in Alexandria, and it was the dominant means of learning anatomy. After both of these men died, the popularity of anatomical dissection decreased until it was not used at all. It was not revived until the 12th century and it became increasingly popular in the 17th century and has been used ever since.File:Rembrandt - The Anatomy Lesson of Dr Nicolaes Tulp.jpg|thumb|The Anatomy Lesson of Dr. Nicolaes Tulp by Rembrandt shows an anatomy lesson taking place in Amsterdam in 1632.
Even though both Herophilus and Erasistratus had permission to use cadavers for dissection, there was still a large amount of taboo surrounding the use of cadavers for anatomical purposes, and these feelings continued for hundreds of years. From the time that anatomical dissection gained its roots in the 3rd century to around the 18th century, it was associated with dishonor, immorality, and unethical behavior. Many of these notions were because of religious beliefs and esthetic taboos, and were deeply entrenched in the beliefs of the public and the church. As mentioned above, the dissection of cadavers began to once again take hold around the 12th century. At this time dissection was still seen as dishonorable; however, it was not outright banned. Instead, the church put forth certain edicts for banning and allowing certain practices. One that was monumental for scientific advancement was issued by the Holy Roman emperor Frederick II in 1231. This decree stated that a human body would be dissected once every five years for anatomical studies, and that attendance was required for all who were training to or currently practicing medicine or surgery. This led to the first sanctioned human dissection since 300 B.C., which was performed publicly by Mondino de Liuzzi. This time period created a great deal of enthusiasm in what human dissection could do for science and attracted students from all over Europe to begin studying medicine.
In light of the new discoveries and advancements that were being made, religious moderation of dissection relaxed significantly; however, the public perception of it was still negative. Because of this perception, the only legal source of cadavers was the corpses of criminals who were executed, usually by hanging. Many of the offenders whose crimes “warranted” dissection and their families even considered dissection to be more terrifying and demeaning than the crime or death penalty itself. There were many fights and sometimes even riots when relatives and friends of the deceased and soon to be dissected tried to stop the delivery of corpses from the place of hanging to the anatomists. The government at the time took advantage of these qualms by using dissection as a threat against committing serious crimes. They even increased the number of crimes that were punished by hanging to over 200 offenses. Nevertheless, as dissection of cadavers became even more popular, anatomists were forced to find other ways to obtain cadavers.
As demand increased for cadavers from universities across the world, people began grave-robbing. These corpses were transported and put on sale for local anatomy professors to take back to their students. The public tended to look the other way when it came to grave-robbing because the affected was usually poor or a part of a marginalized society. There was more out-cry if the affluent or prominent members of society were affected, and this led to a riot in New York most commonly referred to as the Resurrection Riot of 1788. It all started when a doctor waved the arm of a cadaver at a young boy looking through the window, who then went home and told his father. Worrying that his recently deceased wife's grave had been robbed, he went to check on it and realized that it had been. This story spread and people accused local physicians and anatomists. The riot grew to 5,000 people and by the end medical students and doctors were beaten and six people were killed. This led to many legal adjustments such as the Anatomy Acts put forth by the U.S. government. These acts opened up other avenues to obtaining corpses for scientific purposes with Massachusetts being the first to do so. In 1830 and 1833, they allowed unclaimed bodies to be used for dissection. Laws in almost every state were subsequently passed and grave-robbing was essentially eradicated.
Although dissection became increasingly accepted throughout the years, it was still very much disapproved by the American public in the beginning of the 20th century. The disapproval mostly came from religious objections and dissection being associated with unclaimed bodies and therefore a mark of poverty. There were many people that attempted to display dissection in a positive light, for example 200 prominent New York physicians publicly said they would donate their bodies after their death. This and other efforts only helped in minor ways, and public opinion was much more affected by the exposure of the corrupt funeral industry. It was found that the cost of dying was incredibly high and a large amount of funeral homes were scamming people into paying more than they had to. These exposures did not necessarily remove stigma but created fear that a person and their families would be victimized by scheming funeral directors, therefore making people reconsider body donation.
In art
Since early history, the instances of inclusion and representation of corpses in art have been numerous; for instance, as in Neo-Assyrian sculpted reliefs of floating corpses on a river, and in Aristophanes's comedy The Frogs, to memento mori and cadaver monuments.The study and teaching of anatomy through the ages would not have been possible without sketches and detailed drawings of discoveries when working with human corpses. The artistic depiction of the placement of body parts plays a crucial role in studying anatomy and in assisting those working with the human body. These images serve as the only glance into the body that most will never witness in person.
Da Vinci collaborated with Andreas Vesalius who also worked with many young artists to illustrate Vesalius’ book "De Humani Corporis Fabrica" and this launched the use of labelling anatomical features to better describe them. It is believed that Vesalius used cadavers of executed criminals in his work due to the inability to secure bodies for this type of work and dissection. He also went to great measures to utilize a spirit of art appreciation in his drawings and also employed other artists to assist in these illustrations.
The study of the human body was not isolated to only medical doctors and students, as many artists reflected their expertise through masterful drawings and paintings. The detailed study of human and animal anatomy, as well as the dissection of corpses, was utilized by early Italian renaissance man Leonardo da Vinci in an effort to more accurately depict the human figure through his work. He studied the anatomy from an exterior perspective as an apprentice under Andrea del Verrocchio that started in 1466. During his apprenticeship, Leonardo mastered drawing detailed versions of anatomical structures such as muscles and tendons by 1472.
His approach to the depiction of the human body was much like that of the study of architecture, providing multiple views and three-dimensional perspectives of what he witnessed in person. One of the first examples of this is using the three dimensional perspectives to draw a skull in 1489. Further study under Verrocchio, some of Leonardo da Vinci's anatomical work was published in his book A Treatise on Painting. A few years later, in 1516, he partnered with professor and anatomist Marcantonio della Torre in Florence, Italy to take his study further. The two began to conduct dissections on human corpses at the Hospital of Santa Maria Nuova and later at hospitals in Milan and Rome. Through his study, da Vinci was perhaps the first to accurately draw the natural position of the human fetus in the womb, via cadaver of a late mother and her unborn child. It is speculated that he conducted approximately 30 dissections total. His work with cadavers allowed him to portray the first drawings of the umbilical cord, uterus, cervix and vagina and ultimately dispute beliefs that the uterus had multiple chambers in the case of multiple births. It is reported that between 1504 and 1507, he experimented with the brain of an ox by injecting a tube into the ventricular cavities, injecting hot wax, and scraping off the brain leaving a cast of the ventricles. Da Vinci's efforts proved to be very helpful in the study of the brain's ventricular system. Da Vinci gained an understanding of what was happening mechanically under the skin to better portray the body through art. For example, he removed the facial skin of the cadaver to more closely observe and draw the detailed muscles that move the lips to obtain a holistic understanding of that system. He also conducted a thorough study of the foot and ankle that continues to be consistent with current clinical theories and practice. His work with the shoulder also mirrors modern understanding of its movement and functions, utilizing a mechanical description likening it to ropes and pulleys. He also was one of the first to study neuroanatomy and made great advances regarding the understanding of the anatomy of the eye, optic nerves and the spine, but unfortunately his later discovered notes were disorganized and difficult to decipher due to his practice of reverse script writing.
For centuries artists have used their knowledge gleaned from the study of anatomy and the use of cadavers to better present a more accurate and lively representation of the human body in their artwork and mostly in paintings. It is thought that Michelangelo and/or Raphael may have also conducted dissections.