Dissection (from Latin ' "to cut to pieces"; also called anatomization) is the dismembering of the body of a deceased animal or plant to study its anatomical structure. Autopsy is used in pathology and forensic medicine to determine the cause of death in humans. Less extensive dissection of plants and smaller animals preserved in a formaldehyde solution is typically carried out or demonstrated in biology and natural science classes in middle school and high school, while extensive dissections of cadavers of adults and children, both fresh and preserved are carried out by medical students in medical schools as a part of the teaching in subjects such as anatomy, pathology and forensic medicine. Consequently, dissection is typically conducted in a morgue or in an anatomy lab.
Dissection has been used for centuries to explore anatomy. Objections to the use of cadavers have led to the use of alternatives including virtual dissection of computer models.
In the field of surgery, the term "dissection" or "dissecting" means more specifically the practice of separating an anatomical structure (an organ, nerve or blood vessel) from its surrounding connective tissue in order to minimize unwanted damage during a surgical procedure.
Overview
Plant and animal bodies are dissected to analyze the structure and function of its components. Dissection is practised by students in courses of biology, botany, zoology, and veterinary science, and sometimes in arts studies. In medical schools, students dissect human cadavers to learn anatomy. Zoötomy is sometimes used to describe "dissection of an animal".
Human dissection
A key principle in the dissection of human cadavers (sometimes called androtomy) is the prevention of human disease to the dissector. Prevention of transmission includes the wearing of protective gear, ensuring the environment is clean, dissection technique and pre-dissection tests to specimens for the presence of HIV and hepatitis viruses.
thumb|Dissection tools. Left to right: [[scalpels with No. 20 and No. 12 blades, two forceps and scissors]]
Most dissection involves the careful isolation and removal of individual organs, called the Virchow technique. An alternative more cumbersome technique involves the removal of the entire organ body, called the Letulle technique. This technique allows a body to be sent to a funeral director without waiting for the sometimes time-consuming dissection of individual organs.
History
thumb|upright=1.2<!--width for small image detail-->|[[Galen (129 – c. 200 AD), Opera omnia, dissection of a pig. Engraving made in Venice, 1565]]
Classical antiquity
Human dissections were carried out by the Greek physicians Herophilus of Chalcedon and Erasistratus of Chios in the early part of the third century BC. Before then, animal dissection had been carried out systematically starting from the fifth century BC. During this period, the first exploration into full human anatomy was performed rather than a base knowledge gained from 'problem-solution' delving. While there was a deep taboo in Greek culture concerning human dissection, there was at the time a strong push by the Ptolemaic government to build Alexandria into a hub of scientific study. so anatomists relied on the cadavers of animals or made observations of human anatomy from injuries of the living. Galen, for example, dissected the Barbary macaque and other primates, assuming their anatomy was basically the same as that of humans, and supplemented these observations with knowledge of human anatomy which he acquired while tending to wounded gladiators.
Celsus wrote in On Medicine I Proem 23, "Herophilus and Erasistratus proceeded in by far the best way: they cut open living men - criminals they obtained out of prison from the kings and they observed, while their subjects still breathed, parts that nature had previously hidden, their position, color, shape, size, arrangement, hardness, softness, smoothness, points of contact, and finally the processes and recesses of each and whether any part is inserted into another or receives the part of another into itself."
Galen was another such writer who was familiar with the studies of Herophilus and Erasistratus.
India
thumb|upright|left|The Ayurvedic Man., c. 18th century
The ancient societies that were rooted in India left behind artwork on how to kill animals during a hunt. The images showing how to kill most effectively depending on the game being hunted relay an intimate knowledge of both external and internal anatomy as well as the relative importance of organs. According to that source, an autopsy should be performed in any case of untimely demise. Shari'ah law has applied to a greater or lesser extent within Muslim countries, Islamic physicians such as Ibn Zuhr (Avenzoar) (1091–1161) in Al-Andalus, Saladin's physician Ibn Jumay during the 12th century, Abd el-Latif in Egypt , and Ibn al-Nafis in Syria and Egypt in the 13th century may have practiced dissection, but it remains ambiguous whether or not human dissection was practiced. Ibn al-Nafis, a physician and Muslim jurist, suggested that the "precepts of Islamic law have discouraged us from the practice of dissection, along with whatever compassion is in our temperament", The book was an educational text of medicine and surgery which included detailed illustrations. and to a lesser extent into Chinese medicine.
Christian Europe
thumb|upright|left|A dissection in [[Realdo Colombo's De Re Anatomica, 1559]]
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Throughout the history of Christian Europe, the dissection of human cadavers for medical education has experienced various cycles of legalization and proscription in different countries. Dissection was rare during the Middle Ages, but it was practised, with evidence from at least as early as the 13th century. The practice of autopsy in Medieval Western Europe is "very poorly known" as few surgical texts or conserved human dissections have survived.
A modern Jesuit scholar has claimed that the Christian theology contributed significantly to the revival of human dissection and autopsy by providing a new socio-religious and cultural context in which the human cadaver was no longer seen as sacrosanct.<!-- we mention this, but discussing it would be for a religion'n'ethics article really -->
A non-existent edict of the 1163 Council of Tours and an early 14th-century decree of Pope Boniface VIII have mistakenly been identified as prohibiting dissection and autopsy; misunderstanding or extrapolation from these edicts may have contributed to reluctance to perform such procedures.