Dissection

Dissection

Overview

Dissection is usually the process of disassembling and observing something to determine its internal structure and as an aid to discerning the functions and relationships of its components.

In the past, anatomization
Anatomy
Anatomy is a branch of biology and medicine that is the consideration of the structure of living things. It is a general term that includes human anatomy, animal anatomy , and plant anatomy...

 of the body of a convicted person was sometimes ordered as part of the punishment. It happened in 1805 in Massachusetts to James Halligan and Dominic Daley
Dominic Daley
Dominic Daley was an Irishman who emigrated to America and lived and worked in Boston. He and James Halligan were arrested on November 12, 1805 and convicted for the murder of Marcus Lyon. They protested their innocence, Jean-Louis Lefebvre de Cheverus, a priest from Boston came, with great...

 after their public hanging
Hanging
Hanging is the lethal suspension of a person by a ligature. The Oxford English Dictionary states that hanging in this sense is "specifically to put to death by suspension by the neck", though it formerly also referred to crucifixion and death by impalement in which the body would remain...

.
Discussion
Ask a question about 'Dissection'
Start a new discussion about 'Dissection'
Answer questions from other users
Full Discussion Forum
 
Unanswered Questions
Encyclopedia

Dissection is usually the process of disassembling and observing something to determine its internal structure and as an aid to discerning the functions and relationships of its components.

In the past, anatomization
Anatomy
Anatomy is a branch of biology and medicine that is the consideration of the structure of living things. It is a general term that includes human anatomy, animal anatomy , and plant anatomy...

 of the body of a convicted person was sometimes ordered as part of the punishment. It happened in 1805 in Massachusetts to James Halligan and Dominic Daley
Dominic Daley
Dominic Daley was an Irishman who emigrated to America and lived and worked in Boston. He and James Halligan were arrested on November 12, 1805 and convicted for the murder of Marcus Lyon. They protested their innocence, Jean-Louis Lefebvre de Cheverus, a priest from Boston came, with great...

 after their public hanging
Hanging
Hanging is the lethal suspension of a person by a ligature. The Oxford English Dictionary states that hanging in this sense is "specifically to put to death by suspension by the neck", though it formerly also referred to crucifixion and death by impalement in which the body would remain...

. The bodies were taken to the local slaughterhouse. Their remains were denied a burial.

In biology


Dissection is usually applied to the examination of plants and animals. The term is also used in relation to mechanisms, computer programs, written materials, etc., as a synonym for terms such as reverse engineering
Reverse engineering
Reverse engineering is the process of discovering the technological principles of a device, object, or system through analysis of its structure, function, and operation...

 or literary deconstruction
Deconstruction
Deconstruction is a term introduced by French philosopher Jacques Derrida in his 1967 book Of Grammatology. Although he carefully avoided defining the term directly, he sought to apply Martin Heidegger's concept of Destruktion or Abbau, to textual reading...

. Dissection is usually performed by students in courses of biology
Biology
Biology is a natural science concerned with the study of life and living organisms, including their structure, function, growth, origin, evolution, distribution, and taxonomy. Biology is a vast subject containing many subdivisions, topics, and disciplines...

, botany
Botany
Botany, plant science, or plant biology is a branch of biology that involves the scientific study of plant life. Traditionally, botany also included the study of fungi, algae and viruses...

 and anatomy
Anatomy
Anatomy is a branch of biology and medicine that is the consideration of the structure of living things. It is a general term that includes human anatomy, animal anatomy , and plant anatomy...

 and in association with medical and arts
ARts
aRts, which stands for analog Real time synthesizer, is an audio framework that is no longer under development. It is best known for previously being used in KDE to simulate an analog synthesizer....

 studies.

Vivisection
Vivisection
Vivisection is defined as surgery conducted for experimental purposes on a living organism, typically animals with a central nervous system, to view living internal structure...

 refers to the dissection of a living animal, often for the purposes of physiological
Physiology
Physiology is the science of the function of living systems. This includes how organisms, organ systems, organs, cells, and bio-molecules carry out the chemical or physical functions that exist in a living system. The highest honor awarded in physiology is the Nobel Prize in Physiology or...

 investigation and nowadays always under heavy sedation. However, the term is no longer widely used, in part because more sophisticated techniques have superseded it for many applications. The term is now almost entirely used in a pejorative sense by those who oppose animal testing
Animal testing
Animal testing, also known as animal experimentation, animal research, and in vivo testing, is the use of non-human animals in experiments. Worldwide it is estimated that the number of vertebrate animals—from zebrafish to non-human primates—ranges from the tens of millions to more than 100 million...

 of any sort.

Dissection is often performed as a part of determining a cause of death in autopsy
Autopsy
An autopsy—also known as a post-mortem examination, necropsy , autopsia cadaverum, or obduction—is a highly specialized surgical procedure that consists of a thorough examination of a corpse to determine the cause and manner of death and to evaluate any disease or injury that may be present...

 (on humans) and necropsy (on animals) and is an intrinsic part of forensic medicine, such as would be practiced by a coroner
Coroner
A coroner is a government official who* Investigates human deaths* Determines cause of death* Issues death certificates* Maintains death records* Responds to deaths in mass disasters* Identifies unknown dead* Other functions depending on local laws...

.

History


Early systematic human dissections were carried out by the Greek physicians Herophilus of Chalcedon
Herophilos
Herophilos , sometimes Latinized Herophilus , was a Greek physician. Born in Chalcedon, he spent the majority of his life in Alexandria. He was the first scientist to systematically perform scientific dissections of human cadavers and is deemed to be the first anatomist. Herophilos recorded his...

 and Erasistratus of Chios in the early part of the third century BC. Before and after this time investigators appeared to largely limit themselves to non-human animals. Roman law
Roman law
Roman law is the legal system of ancient Rome, and the legal developments which occurred before the 7th century AD — when the Roman–Byzantine state adopted Greek as the language of government. The development of Roman law comprises more than a thousand years of jurisprudence — from the Twelve...

 forbade dissection and autopsy of the human body, so physicians such as Galen
Galen
Aelius Galenus or Claudius Galenus , better known as Galen of Pergamon , was a prominent Roman physician, surgeon and philosopher...

 were unable to work on cadavers. Galen for example dissected the Barbary Macaque
Barbary Macaque
The Barbary Macaque , or Common macaque, is a macaque with no tail. Found in the Atlas Mountains of Algeria and Morocco with a small population, of unknown origin, in Gibraltar, the Barbary Macaque is one of the best-known Old World monkey species. Besides humans, they are the only primates that...

 and other primates, assuming their anatomy was basically the same as that of humans.

It is not clear whether or not human dissections were also conducted by Arabic physicians
Islamic medicine
In the history of medicine, Islamic medicine, Arabic medicine or Arabian medicine refers to medicine developed in the Islamic Golden Age, and written in Arabic, the lingua franca of Islamic civilization....

. Islamic scholars
Ulema
Ulama , also spelt ulema, refers to the educated class of Muslim legal scholars engaged in the several fields of Islamic studies. They are best known as the arbiters of shari‘a law...

 such as Al-Ghazali
Al-Ghazali
Abu Hāmed Mohammad ibn Mohammad al-Ghazzālī , known as Algazel to the western medieval world, born and died in Tus, in the Khorasan province of Persia was a Persian Muslim theologian, jurist, philosopher, and mystic....

 expressed support for its practice Some of the Arabic physicians who may have performed dissections include Ibn Zuhr
Ibn Zuhr
Abū Merwān ’Abdal-Malik ibn Zuhr was a Muslim physician, surgeon and teacher in Al-Andalus.He was born at Seville...

 (Avenzoar) (1091–1161) in Al-Andalus
Al-Andalus
Al-Andalus was the Arabic name given to a nation and territorial region also commonly referred to as Moorish Iberia. The name describes parts of the Iberian Peninsula and Septimania governed by Muslims , at various times in the period between 711 and 1492, although the territorial boundaries...

, Saladin
Saladin
Ṣalāḥ ad-Dīn Yūsuf ibn Ayyūb , better known in the Western world as Saladin, was an Arabized Kurdish Muslim, who became the first Sultan of Egypt and Syria, and founded the Ayyubid dynasty. He led Muslim and Arab opposition to the Franks and other European Crusaders in the Levant...

's physician Ibn Jumay' during the 12th century, Abd-el-latif in Egypt
Egypt
Egypt , officially the Arab Republic of Egypt, Arabic: , is a country mainly in North Africa, with the Sinai Peninsula forming a land bridge in Southwest Asia. Egypt is thus a transcontinental country, and a major power in Africa, the Mediterranean Basin, the Middle East and the Muslim world...

 circa 1200, and Ibn al-Nafis in Syria
Syria
Syria , officially the Syrian Arab Republic , is a country in Western Asia, bordering Lebanon and the Mediterranean Sea to the West, Turkey to the north, Iraq to the east, Jordan to the south, and Israel to the southwest....

 and Egypt during the 13th century.

Unlike pagan Rome, Christian Europe did not exercise a universal prohibition of the dissection and autopsy of the human body and such examinations were carried out regularly from at least the 13th century. It has even been suggested 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
Cadaver
A cadaver is a dead human body.Cadaver may also refer to:* Cadaver tomb, tomb featuring an effigy in the form of a decomposing body* Cadaver , a video game* cadaver A command-line WebDAV client for Unix....

 was no longer seen as sacrosanct.
Throughout history, the dissection of human cadavers for medical education has experienced various cycles of legalization and proscription in different countries. An edict of the 1163 Council of Tours
Council of Tours
In the medieval Roman Catholic church there were several Councils of Tours, that city being an old seat of Christianity, and considered fairly centrally located in France. Athenius, Bishop of Rennes, took part in the First Council of Tours in AD 461...

, and an early 14th century decree of Pope Boniface VIII
Pope Boniface VIII
Pope Boniface VIII , born Benedetto Gaetani, was Pope of the Catholic Church from 1294 to 1303. Today, Boniface VIII is probably best remembered for his feuds with Dante, who placed him in the Eighth circle of Hell in his Divina Commedia, among the Simonists.- Biography :Gaetani was born in 1235 in...

 have mistakenly been identified as prohibiting dissection and autopsy, but no universal prohibition of dissection or autopsy was exercised during the Middle Ages. Rather, the era witnessed the revival of an interest in medical studies, and a renewal in human dissection and autopsy. Some European countries began legalizing the dissection of executed criminals for educational purposes in the late 13th and early 14th centuries, and Mondino de Liuzzi
Mondino de Liuzzi
Mondino de Luzzi, or de Liuzzi or de Lucci, , also known as Mundinus, was an Italian physician, anatomist, and professor of surgery who lived and worked in Bologna...

 carried out the first recorded public dissection around 1315. Vesalius
Vesalius
Andreas Vesalius was a Flemish anatomist, physician, and author of one of the most influential books on human anatomy, De humani corporis fabrica . Vesalius is often referred to as the founder of modern human anatomy. Vesalius is the Latinized form of Andries van Wesel...

 in the 16th century carried out numerous dissections in the process of performing some of the most extensive anatomical investigations up to his time, but was attacked frequently by other physicians for his disagreement with Galen's studies of human anatomy. For many years it was assumed that Vesalius's pilgrimage to Palestine was an escape from pressures of the Inquisition
Inquisition
The Inquisition, Inquisitio Haereticae Pravitatis , was the "fight against heretics" by several institutions within the justice-system of the Roman Catholic Church. It started in the 12th century, with the introduction of torture in the persecution of heresy...

 brought as a result of his work with cadavers. Today this is generally considered to be without foundation (see C.D. O'Malley Andreas Vesalius' Pilgrimage, Isis 45:2, 1954) and is dismissed by modern biographers.

In England, dissection remained entirely prohibited until 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 Royal College of Physicians
Royal College of Physicians
The Royal College of Physicians of London was founded in 1518 as the College of Physicians by royal charter of King Henry VIII in 1518 - the first medical institution in England to receive a royal charter...

 and Company of Barber-Surgeons were the only two groups permitted to carry out dissections, and had an annual quota of ten cadavers between them. As a result of pressure from anatomists, especially in the rapidly growing medical schools, the Murder Act 1752 allowed the bodies of executed murderers to be dissected for anatomical research and education. By the 19th century this supply of cadavers proved insufficient, however, due to both the continuing expansion of medical schools, and the creation of a number of private medical schools, which lacked legal access to cadavers. A thriving black market arose in cadavers and body parts, leading to the creation of an entire profession of body-snatcher, and even more extremely, the infamous 1827 and 1828 Burke and Hare murders, in which 17 people were murdered in order to sell their cadavers to anatomists. The resulting public outcry largely led to the passage of the Anatomy Act 1832
Anatomy Act 1832
The Anatomy Act 1832 was a United Kingdom Act of Parliament that gave freer license to doctors, teachers of anatomy, and bona fide medical students to dissect donated bodies...

, which greatly increased the legal supply of cadavers for dissection. (See also: History of anatomy in the 19th century
History of anatomy in the 19th century
The 19th century saw anatomists largely finalise and systematise the descriptive human anatomy of the previous century. The discipline also progressed to establish growing sources of knowledge in histology and developmental biology, not only of humans but also of animals.-Anatomical science:Though...

.)

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
Peninsula College of Medicine and Dentistry
Peninsula College of Medicine and Dentistry is a Medical and Dental school in England, run in partnership with the University of Exeter, the University of Plymouth and the...

 in the UK, founded in 2000, became the first modern medical school to carry out its anatomy education without dissection, though most medical schools continue to see experience with actual cadavers as preferable to entirely computer-based education.

Dissections of non-human animals have also been used for educational purposes, often in general science education where the use of human cadavers would not be justified. In the U.S., dissection of frogs became common in college biology classes from the 1920s, and gradually began to be introduced at earlier stages of education. By 1988, an estimated 75–80% of American high school biology students were participating in a frog dissection, with a trend towards introduction in elementary schools. The dissected frogs are most commonly from the Rana genus
Rana (genus)
Rana is a genus of frogs. Species include such archetypal pond frogs as the common frog of Europe, brown frogs, and the New and Old World true frogs, including the various species of leopard frogs and the American bullfrog. Members of this genus are found through much of Eurasia, North America,...

. Other popular animals for high-school dissection at the time of that survey were, among vertebrates, fetal pig
Fetal pig
Fetal pigs are unborn pigs used in elementary as well as advanced biology classes as objects for dissection. Pigs, as a mammalian species, provide a good specimen for the study of physiological systems and processes.-Use in biology labs:...

s, perch
Perch
Perch is a common name for fish of the genus Perca, freshwater gamefish belonging to the family Percidae. The perch, of which there are three species in different geographical areas, lend their name to a large order of vertebrates: the Perciformes, from the Greek perke meaning spotted, and the...

, and cat
Cat
The cat , also known as the domestic cat or housecat to distinguish it from other felids and felines, is a small, usually furry, domesticated, carnivorous mammal that is valued by humans for its companionship and for its ability to hunt vermin and household pests...

s; and among invertebrates, earthworm
Earthworm
Earthworm is the common name for the largest members of Oligochaeta in the phylum Annelida. In classical systems they were placed in the order Opisthopora, on the basis of the male pores opening posterior to the female pores, even though the internal male segments are anterior to the female...

s, grasshopper
Grasshopper
The grasshopper is an insect of the suborder Caelifera in the order Orthoptera. To distinguish it from bush crickets or katydids, it is sometimes referred to as the short-horned grasshopper...

s, crayfish
Crayfish
Crayfish, crawfish, or crawdads – members of the superfamilies Astacoidea and Parastacoidea – are freshwater crustaceans resembling small lobsters, to which they are related...

, and starfish.

Controversy over 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 alternate 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 also gave considerable publicity to anti-dissection advocates: Graham appeared in a 1987 Apple Computer
Apple Computer
Apple Inc. is an American multinational corporation that designs and markets consumer electronics, computer software, and personal computers. The company's best-known hardware products include the Macintosh line of computers, the iPod, the iPhone and the iPad...

 commercial for the virtual-dissection software Operation Frog. The state of California passed a Student's Rights Bill in 1988 requiring that objecting students be allowed to complete alternative projects. The trend towards students opting out of dissection increased through the 1990s.

Tools used



The following are tools commonly used in biological dissection.
  • Scalpel
    Scalpel
    A scalpel, or lancet, is a small and extremely sharp bladed instrument used for surgery, anatomical dissection, and various arts and crafts . Scalpels may be single-use disposable or re-usable. Re-usable scalpels can have attached, resharpenable blades or, more commonly, non-attached, replaceable...

  • Scissors
    Scissors
    Scissors are hand-operated cutting instruments. They consist of a pair of metal blades pivoted so that the sharpened edges slide against each other when the handles opposite to the pivot are closed. Scissors are used for cutting various thin materials, such as paper, cardboard, metal foil, thin...

     (dissecting scissors)
  • Thumb Forceps
    Forceps
    Forceps or forcipes are a handheld, hinged instrument used for grasping and holding objects. Forceps are used when fingers are too large to grasp small objects or when many objects need to be held at one time while the hands are used to perform a task. The term 'forceps' is used almost exclusively...

     or Fine point splinter
  • Mall probe and seeker
  • Surgical Spatula
    Spatula
    The term spatula is used to refer to various small implements with a broad, flat, flexible blade used to mix, spread and lift materials including foods, drugs, plaster and paints...

  • Magnifying glass
    Magnifying glass
    A magnifying glass is a convex lens that is used to produce a magnified image of an object. The lens is usually mounted in a frame with a handle ....

  • Chain & Hooks (surgical)
  • Razor
    Razor
    A razor is a bladed tool primarily used in the removal of unwanted body hair through the act of shaving. Kinds of razors include straight razors, disposable razors and electric razors....

  • Blow Pipe (surgical)
  • Prong (surgical)
  • Teasing needles
  • Pipette
    Pipette
    A pipette is a laboratory tool used to transport a measured volume of liquid.-Use and variations:Pipettes are commonly used in molecular biology, analytical chemistry as well as medical tests...

     or Medicine dropper
  • Ruler
    Ruler
    A ruler, sometimes called a rule or line gauge, is an instrument used in geometry, technical drawing, printing and engineering/building to measure distances and/or to rule straight lines...

     or caliper
    Caliper
    A caliper is a device used to measure the distance between two opposing sides of an object. A caliper can be as simple as a compass with inward or outward-facing points...

  • T pin
    Pin
    A pin is a device used for fastening objects or material together.Pin may also refer to:* Award pin, a small piece of metal or plastic with a pin attached given as an award for some achievement...

    s
  • Dissecting Pan

External links