Dissection
Dissection | |
---|---|
Identifiers | |
MeSH | D004210 |
Anatomical terminology |
Dissection (from
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 to the practice of separating an anatomical structure (an
Overview
Plant and animal bodies are dissected to analyze the structure and function of its components. Dissection is practised by students in courses of
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[2] and pre-dissection tests to specimens for the presence of HIV and hepatitis viruses.[3] Specimens are dissected in morgues or anatomy labs. When provided, they are evaluated for use as a "fresh" or "prepared" specimen.[3] A "fresh" specimen may be dissected within some days, retaining the characteristics of a living specimen, for the purposes of training. A "prepared" specimen may be preserved in solutions such as formalin and pre-dissected by an experienced anatomist, sometimes with the help of a diener.[3] This preparation is sometimes called prosection.[4]
Most dissection involves the careful isolation and removal of individual organs, called the
Autopsy and necropsy
Dissection is used to help to determine the cause of death in
History
Classical antiquity
Human dissections were carried out by the
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
The ancient societies that were rooted in India left behind artwork on how to kill animals during a hunt.
Early in the history of India (2nd to 3rd century), the Arthashastra described the 4 ways that death can occur and their symptoms: drowning, hanging, strangling, or asphyxiation.[15] According to that source, an autopsy should be performed in any case of untimely demise.[15]
The practice of dissection flourished during the 7th and 8th century. It was under their rule that medical education was standardized. This created a need to better understand human anatomy, so as to have educated surgeons. Dissection was limited by the religious taboo on cutting the human body. This changed the approach taken to accomplish the goal. The process involved the loosening of the tissues in streams of water before the outer layers were sloughed off with soft implements to reach the musculature. To perfect the technique of slicing, the prospective students used gourds and squash. These techniques of dissection gave rise to an advanced understanding of the anatomy and the enabled them to complete procedures used today, such as rhinoplasty.[14]
During medieval times the anatomical teachings from India spread throughout the known world; however, the practice of dissection was stunted by Islam.[14] The practice of dissection at a university level was not seen again until 1827, when it was performed by the student Pandit Madhusudan Gupta.[14] Through the 1900s, the university teachers had to continually push against the social taboos of dissection, until around 1850 when the universities decided that it was more cost effective to train Indian doctors than bring them in from Britain.[14] Indian medical schools were, however, training female doctors well before those in England.[14]
The current state of dissection in India is deteriorating. The number of hours spent in dissection labs during medical school has decreased substantially over the last twenty years.[14] The future of anatomy education will probably be an elegant mix of traditional methods and integrative computer learning.[14] The use of dissection in early stages of medical training has been shown more effective in the retention of the intended information than their simulated counterparts.[14] However, there is use for the computer-generated experience as review in the later stages.[14] The combination of these methods is intended to strengthen the students' understanding and confidence of anatomy, a subject that is infamously difficult to master.[14] There is a growing need for anatomist—seeing as most anatomy labs are taught by graduates hoping to complete degrees in anatomy—to continue the long tradition of anatomy education.[14]
Islamic world
From the beginning of the
Tibet
Christian Europe
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,[26] with evidence from at least as early as the 13th century.[27][28][29] The practice of autopsy in Medieval Western Europe is "very poorly known" as few surgical texts or conserved human dissections have survived.[30] 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.[27]
An edict of the
Frederick II (1194–1250), the Holy Roman emperor, ruled that any that were studying to be a physician or a surgeon must attend a
The Italian Galeazzo di Santa Sofia made the first public dissection north of the Alps in Vienna in 1404.[33]
The Catholic Church is known to have ordered an autopsy on conjoined twins Joana and Melchiora Ballestero in Hispaniola in 1533 to determine whether they shared a soul. They found that there were two distinct hearts, and hence two souls, based on the ancient Greek philosopher Empedocles, who believed the soul resided in the heart.[35]
Human dissection was also practised by
Anatomization was sometimes ordered as a form of punishment, as, for example, in 1806 to James Halligan and Dominic Daley after their public hanging in Northampton, Massachusetts.[36]
In modern Europe, dissection is routinely practised in biological research and education, in medical schools, and to determine the cause of death in autopsy. It is generally considered a necessary part of learning and is thus accepted culturally. It sometimes attracts controversy, as when Odense Zoo decided to dissect lion cadavers in public before a "self-selected audience".[37][38]
Britain
In Britain, dissection remained entirely prohibited from the end of the Roman conquest and through the Middle Ages to the 16th century, when a series of royal edicts gave specific groups of physicians and surgeons some limited rights to dissect cadavers. The permission was quite limited: by the mid-18th century, the
By the 21st century, the availability of interactive computer programs and changing public sentiment led to renewed debate on the use of cadavers in medical education. The Peninsula College of Medicine and Dentistry in the UK, founded in 2000, became the first modern medical school to carry out its anatomy education without dissection.[40]
United States
In the United States, dissection of frogs became common in college biology classes from the 1920s, and were gradually introduced at earlier stages of education. By 1988, some 75 to 80 percent of American high school biology students were participating in a frog dissection, with a trend towards introduction in elementary schools. The frogs are most commonly from the genus Rana. Other popular animals for high-school dissection at the time of that survey were, among vertebrates, fetal pigs, perch, and cats; and among invertebrates, earthworms, grasshoppers, crayfish, and starfish.[41] About six million animals are dissected each year in United States high schools (2016), not counting medical training and research. Most of these are purchased already dead from slaughterhouses and farms.[42]
Dissection in U.S. high schools became prominent in 1987, when a California student, Jenifer Graham, sued to require her school to let her complete an alternative project. The court ruled that mandatory dissections were permissible, but that Graham could ask to dissect a frog that had died of natural causes rather than one that was killed for the purposes of dissection; the practical impossibility of procuring a frog that had died of natural causes in effect let Graham opt out of the required dissection. The suit gave publicity to anti-dissection advocates. Graham appeared in a 1987
In the United States, 17 states[b] along with Washington, D.C. have enacted dissection-choice laws or policies that allow students in primary and secondary education to opt out of dissection. Other states including Arizona, Hawaii, Minnesota, Texas, and Utah have more general policies on opting out on moral, religious, or ethical grounds.[47] To overcome these concerns, J. W. Mitchell High School in New Port Richey, Florida, in 2019 became the first US high school to use synthetic frogs for dissection in its science classes, instead of preserved real frogs.[48][49][50]
As for the dissection of cadavers in undergraduate and medical school, traditional dissection is supported by professors and students, with some opposition, limiting the availability of dissection. Upper-level students who have experienced this method along with their professors agree that "Studying human anatomy with colorful charts is one thing. Using a scalpel and an actual, recently-living person is an entirely different matter."[51]
Acquisition of cadavers
The way in which cadaveric specimens are obtained differs greatly according to country.[52] In the UK, donation of a cadaver is wholly voluntary. Involuntary donation plays a role in about 20 percent of specimens in the US and almost all specimens donated in some countries such as South Africa and Zimbabwe.[52] Countries that practice involuntary donation may make available the bodies of dead criminals or unclaimed or unidentified bodies for the purposes of dissection.[52] Such practices may lead to a greater proportion of the poor, homeless and social outcasts being involuntarily donated.[52] Cadavers donated in one jurisdiction may also be used for the purposes of dissection in another, whether across states in the US,[3] or imported from other countries, such as with Libya.[52] As an example of how a cadaver is donated voluntarily, a funeral home in conjunction with a voluntary donation program identifies a body who is part of the program. After broaching the subject with relatives in a diplomatic fashion, the body is then transported to a registered facility. The body is tested for the presence of HIV and hepatitis viruses. It is then evaluated for use as a "fresh" or "prepared" specimen.[3]
Disposal of specimens
Cadaveric specimens for dissection are, in general, disposed of by cremation. The deceased may then be interred at a local cemetery. If the family wishes, the ashes of the deceased are then returned to the family.[3] Many institutes have local policies to engage, support and celebrate the donors. This may include the setting up of local monuments at the cemetery.[3]
Use in education
Human cadavers are often used in medicine to teach anatomy or surgical instruction.[3][52] Cadavers are selected according to their anatomy and availability. They may be used as part of dissection courses involving a "fresh" specimen so as to be as realistic as possible—for example, when training surgeons.[3] Cadavers may also be pre-dissected by trained instructors. This form of dissection involves the preparation and preservation of specimens for a longer time period and is generally used for the teaching of anatomy.[3]
Alternatives
Some alternatives to dissection may present educational advantages over the use of animal cadavers, while eliminating perceived ethical issues.[53] These alternatives include computer programs, lectures, three dimensional models, films, and other forms of technology. Concern for animal welfare is often at the root of objections to animal dissection.[54] Studies show that some students reluctantly participate in animal dissection out of fear of real or perceived punishment or ostracism from their teachers and peers, and many do not speak up about their ethical objections.[55][56]
One alternative to the use of cadavers is computer technology. At
Advantages and disadvantages
Proponents of animal-free teaching methodologies argue that alternatives to animal dissection can benefit educators by increasing teaching efficiency and lowering instruction costs while affording teachers an enhanced potential for the customization and repeat-ability of teaching exercises. Those in favor of dissection alternatives point to studies which have shown that computer-based teaching methods "saved academic and nonacademic staff time … were considered to be less expensive and an effective and enjoyable mode of student learning [and] … contributed to a significant reduction in animal use" because there is no set-up or clean-up time, no obligatory safety lessons, and no monitoring of misbehavior with animal cadavers, scissors, and scalpels.[59][60][61]
With software and other non-animal methods, there is also no expensive disposal of equipment or hazardous material removal. Some programs also allow educators to customize lessons and include built-in test and quiz modules that can track student performance. Furthermore, animals (whether dead or alive) can be used only once, while non-animal resources can be used for many years—an added benefit that could result in significant cost savings for teachers, school districts, and state educational systems.[59]
Several peer-reviewed comparative studies examining information retention and performance of students who dissected animals and those who used an alternative instruction method have concluded that the educational outcomes of students who are taught basic and advanced biomedical concepts and skills using non-animal methods are equivalent or superior to those of their peers who use animal-based laboratories such as animal dissection.[62][63]
Some reports state that students' confidence, satisfaction, and ability to retrieve and communicate information was much higher for those who participated in alternative activities compared to dissection. Three separate studies at universities across the United States found that students who modeled body systems out of clay were significantly better at identifying the constituent parts of human anatomy than their classmates who performed animal dissection.[64][65][66]
Another study found that students preferred using clay modeling over animal dissection and performed just as well as their cohorts who dissected animals.[67]
In 2008, the National Association of Biology Teachers (NABT) affirmed its support for classroom animal dissection stating that they "Encourage the presence of live animals in the classroom with appropriate consideration to the age and maturity level of the students …NABT urges teachers to be aware that alternatives to dissection have their limitations. NABT supports the use of these materials as adjuncts to the educational process but not as exclusive replacements for the use of actual organisms."[68]
The National Science Teachers Association (NSTA) "supports including live animals as part of instruction in the K-12 science classroom because observing and working with animals firsthand can spark students' interest in science as well as a general respect for life while reinforcing key concepts" of biological sciences. NSTA also supports offering dissection alternatives to students who object to the practice.[69]
The NORINA database lists over 3,000 products which may be used as alternatives or supplements to animal use in education and training.[70] These include alternatives to dissection in schools. InterNICHE has a similar database and a loans system.[71]
Additional images
-
Dissection of a human cheek from Gray's Anatomy (1918)
-
Dissection of a spiny dogfish
-
Dissection of human axilla
-
Human abdomen and thorax
-
Cow brain prepared for dissection
-
Dissection in a secondary school GCSE class
-
Technique of dissection and glycerination in Bovine articulation (tarsus)
See also
- 1788 Doctors' riotin New York City
- Vivisection
- Forensics
- Andreas Vesalius, founder of modern anatomy
- Jean-Joseph Sue, 18th century surgeon and anatomist
Notes
- ^ "the pope did not forbid anatomical dissections but only the dissections performed with the purpose of preserving the bodies for distant burial"[27]
- ^ California, Connecticut, D.C., Florida, Illinois, Louisiana, Maine, Massachusetts, Michigan, New Hampshire, New Jersey, New Mexico, New York, Oregon, Pennsylvania, Rhode Island, Vermont, and Virginia all have statewide laws or department of education policies that allow students to opt out.
References
- S2CID 30909540.
- ^ ISBN 978-1-58829-841-6.
- ^ ISBN 9780199764624.
- ^ "prosect - definition of prosect in English from the Oxford dictionary". www.oxforddictionaries.com. Archived from the original on November 6, 2015. Retrieved 2016-05-10.
- ^ ISBN 9780323287807.
- ^ "Interactive Autopsy". Australian Museum. Retrieved 10 May 2016.
- PMID 1285450.
- ^ S2CID 237608991.
- ^ PMID 26417475.
- ISBN 978-0521177351.
Tragically, the prohibition of human dissection by Rome in 150 BC arrested this progress and few of their findings survived.
- ^ Nutton, Vivian, 'The Unknown Galen', (2002), p. 89
- ^ Von Staden, Heinrich, Herophilus (1989), p. 140
- ^ Lutgendorf, Philip, Hanuman's Tale: The Messages of a Divine Monkey (2007), p. 348
- ^ S2CID 25807230.
- ^ S2CID 29095914.
- ^ PMID 24661712.
- ^ PMID 7876530.
- ^ Ibn Zuhr and the Progress of Surgery, http://muslimheritage.com/article/ibn-zuhr-and-progress-surgery
- ^ Emilie Savage-Smith (1996), "Medicine", in Roshdi Rashed, ed., Encyclopedia of the History of Arabic Science, Vol. 3, pp. 903–962 [951–952]. Routledge, London and New York.
- S2CID 43154531.
- ^ Hajar A Hajar Albinali (2004). "Traditional Medicine Among Gulf Arabs, Part II: Blood-letting". Heart Views. 5 (2): 74–85.
- ^ PMID 23050167.
- ^ Wujastyk, Dominik (2001). The Roots of Ayurveda. Penguin Classics.
- ISBN 978-0471680017.
- ^ Svoboda, Robert E. (1996). Tao and Dharma: Chinese Medicine and Ayurveda. p. 89.
- ISBN 978-3-11-043697-6.
- ^ a b c P Prioreschi, 'Determinants of the revival of dissection of the human body in the Middle Ages', Medical Hypotheses (2001) 56(2), 229–234
- ^ "In the 13th century, the realisation that human anatomy could best be taught by dissection of the human body resulted in its legalisation of publicly dissecting criminals in some European countries between 1283 and 1365" - this was, however, still contrary to the edicts of the Church. Philip Cheung "Public Trust in Medical Research?" (2007), page 36
- ^ "Indeed, very early in the thirteenth century, a religious official, namely, Pope Innocent III (1198-1216), ordered the postmortem autopsy of a person whose death was suspicious". Toby Huff, The Rise Of Modern Science (2003), page 195
- PMID 24904674.)
{{cite journal}}
: CS1 maint: multiple names: authors list (link - ^ 'While during this period the Church did not forbid human dissections in general, certain edicts were directed at specific practices. These included the Ecclesia Abhorret a Sanguine in 1163 by the Council of Tours and Pope Boniface VIII's command to terminate the practice of dismemberment of slain crusaders' bodies and boiling the parts to enable defleshing for return of their bones. Such proclamations were commonly misunderstood as a ban on all dissection of either living persons or cadavers (Rogers & Waldron, 1986)[clarification needed], and progress in anatomical knowledge by human dissection did not thrive in that intellectual climate', Arthur Aufderheide, The Scientific Study of Mummies (2003), p. 5
- natural causes(disease) or whether there had been foul play, poisoning, or physical assault. Indeed, very early in the thirteenth century, a religious official, namely, Pope Innocent III (1198–1216), ordered the postmortem autopsy of a person whose death was suspicious", Toby Huff, The Rise Of Modern Science (2003), p. 195
- ISBN 978-3-211-48952-9.
- ^ See C. D. O'Malley Andreas Vesalius' Pilgrimage, Isis 45:2, 1954
- ^ Freedman, David H. (September 2012). "20 Things you didn't know about autopsies". Discovery. 9: 72.
- S2CID 57560527.
- ^ "Odense Zoo animal dissections: EAZA response". European Association of Zoos and Aquaria. Archived from the original on 13 May 2016. Retrieved 15 May 2016.
- ^ "Animals used for scientific purposes". European Union. Retrieved 15 May 2016.
- ^ Cheung, pp. 37–44
- ^ Cheung, pp. 33, 35
- ISBN 978-0-19-511908-4.
- ^ "Dissection". American Anti-Vivisection Society. 2016. Retrieved 16 February 2016.
- ^ Howard Rosenberg: Apple Computer's 'Frog' Ad Is Taken Off the Air. LA Times, November 10, 1987.
- ISBN 978-0-19-511908-4.
- ^ Orlans et al., pp. 209–211
- ^ Johnson, Dirk (May 29, 1997). "Frogs' Best Friends: Students Who Won't Dissect Them". New York Times. Retrieved 1 May 2010.
- ^ "Your Right Not to Dissect". PETA2.
- ^ Aaro, David (November 30, 2019). "Florida high school first in world to use synthetic frogs for dissection". Fox News. Retrieved November 30, 2019.
- ^ Elassar, Alaa (November 30, 2019). "A Florida high school is the first in the world to provide synthetic frogs for students to dissect". CNN. Retrieved November 30, 2019.
- ^ Lewis, Sophie (November 26, 2019). "Florida high school introduces synthetic frogs for science class dissection". CBS News. Retrieved November 30, 2019.
- ^ Jenner, Andrew (2012). "EMU News". EMU's Cadaver Dissection Gives Pre-Med Students Big Advantage. Retrieved 25 April 2016.
- ^ S2CID 22596215.
- S2CID 143465900. Retrieved 15 February 2016.
- .
- .
- .
- ^ White, Tracie (2011). "Body image: Computerized table lets students do virtual dissection". Stanford Medicine: News Center. Retrieved 20 February 2016.
- ^ Singer, Natasha (7 January 2012). "The Virtual Anatomy, Ready for Dissection". The New York Times. Retrieved 15 February 2016.
- ^ a b Dewhurt, D; Jenkinson, L (1995). "The impact of computer-based alternatives on the use of animals in undergraduate teaching: A pilot study". ATLA. 23 (4): 521–530.
- S2CID 85201408.
- Bibcode:2001PhDT........42Y.
- S2CID 5164145.
- PMID 17728975.
- S2CID 28694409.
- S2CID 28441790.
- PMID 21652509.
- S2CID 19112983.
- ^ "The Use of Animals in Biology Education". Position Statements: National Association of Biology Teachers. National Association of Biology Teachers. Archived from the original on 13 May 2015. Retrieved 3 February 2015.
- ^ "NSTA Position Statement: Responsible Use of Live Animals and Dissection in the Science Classroom". National Science Teachers Association. Retrieved 3 February 2015.
- ^ NORINA
- ^ InterNICHE
Further reading
- C. Celsus, On Medicine, I, Proem 23, 1935, translated by W. G. Spencer (Loeb Classics Library, 1992).
External links
- How to dissect a frog
- Dissection Alternatives
- Human Dissections
- Virtual Frog Dissection
- Alternatives To Animal Dissection in School Science Classes[permanent dead link]
- Research Project on Death and Dead Bodies, last conference: "Death and Dissection" July 2009, Berlin, Germany
- Evolutionary Biology Digital Dissection Collections Dissection photographs for study and teaching from the University at Buffalo
- The Free Dictionary