Cadaver
A cadaver or 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.[1]
Cadaver
The history of the use of cadavers is filled with controversy, scientific advancements, and new discoveries. It all started in 3rd century ancient Greece with two physicians by the name of Herophilus of Chalcedon and Erasistratus of Ceos.[5] They practiced the dissection of cadavers in Alexandria, and it was the dominant means of learning anatomy.[6] 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.[5]
Even though both Herophilus and Erasistratus had permission to use cadavers for dissection there was still a lot 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,[6] 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.[6] 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.[6] This led to the first sanctioned human dissection since 300 B.C., which was performed publicly by Mondino de Liuzzi.[6] 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.
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.[5] 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.[5] 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.[5] 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.[5] 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.[5] Laws in almost every state were subsequently passed and grave-robbing was essentially eradicated.
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 (c. 640 BCE), and in Aristophanes's comedy The Frogs (405 BCE), to memento mori and cadaver monuments.
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.[10] Further study under Verrocchio, some of Leonardo da Vinci's anatomical work was published in his book A Treatise on Painting.[11][self-published source?] 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.[12] It is speculated that he conducted approximately 30 dissections total.[13] 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.[12] 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 brains ventricular system.[14] Da Vinci gained an understanding of what was happening mechanically under the skin to better portray the body through art.[13] 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.[15] He also conducted a thorough study of the foot and ankle that continues to be consistent with current clinical theories and practice.[13] His work with the shoulder also mirrors modern understanding of its movement and functions, utilizing a mechanical description likening it to ropes and pulleys.[13] 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 (mirror writing).[16]
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.[8]
In the present day, cadavers are used within medicine and surgery to further knowledge on human gross anatomy.[22] Surgeons have dissected and examined cadavers before surgical procedures on living patients to identify any possible deviations within the surgical area of interest.[23] New types of surgical procedures can lead to numerous obstacles involved within the procedure which can be eliminated through prior knowledge from the dissection of a cadaver.[24]
Cadavers not only provide medical students and doctors knowledge about the different functions of the human body, but they also provide multiple causes of malfunction within the human body. Galen (250 AD), a Greek physician, was one of the first to associate events that occurred during a human's life with the internal ramifications found later after death. A simple autopsy of a cadaver can help determine origins of deadly diseases or disorders. Autopsies also can provide information on how certain drugs or procedures have been effective within the cadaver and how humans respond to certain injuries.[25]
Appendectomies, the removal of the appendix, are performed 28,000 times a year in the United States and are still practiced on human cadavers and not with technology simulations.[26] Gross anatomy, a common course in medical school studying the visual structures of the body, gives students the opportunity to have a hands-on learning environment. The need for cadavers has also grown outside of academic programs for research. Organizations like Science Care and the Anatomy Gifts Registry help send bodies where they are needed most.[26]
For a cadaver to be viable and ideal for anatomical study and dissection, the body must be refrigerated or the preservation process must begin within 24 hours of death.[27] This preservation may be accomplished by embalming using a mixture of embalming fluids, or with a relatively new method called plastination. Both methods have advantages and disadvantages in regards to preparing bodies for anatomical dissection in the educational setting.
Embalming practice has changed a great deal in the last few hundred years. Modern embalming for anatomical purposes no longer includes evisceration, as this disrupts the organs in ways that would be disadvantageous for the study of anatomy.[30] As with the mixtures of chemicals, embalmers practicing today can use different methods for introducing fluids into the cadaver. Fluid can be injected into the arterial system (typically through the carotid or femoral arteries), the main body cavities, under the skin, or the cadaver can be introduced to fluids at the outer surface of the skin via immersion.[31]
Formaldehyde is very widely used in the process of embalming. It is a fixative, and kills bacteria, fungus, and insects. It prevents decay by keeping decomposing microorganisms from surviving on and in the cadaver. It also cures the tissues it is used in so that they cannot serve as nutrients for these organisms. While formaldehyde is a good antiseptic, it has certain disadvantages as well. When used in embalming, it causes blood to clot and tissues to harden, it turns the skin gray, and its fumes are both malodorous and toxic if inhaled. However, its abilities to prevent decay and tan tissue without ruining its structural integrity have led to its continued widespread use to this day.[30] 041b061a72