decapitation

thumb|Beheadings in an illumination from Jean Froissart|Froissart's Chronicles from the beginning of the 15th century – the execution of Guillaume Sans and his secretary in [[Bordeaux on the orders of Thomas Felton]] thumb|Perseus using the severed head of [[Medusa to turn King Polydectes to stone]] thumb|Depiction of an Ethiopian Empire|Ethiopian emperor executing people, 18th century Decapitation is the total separation of the head from the body. This injury is fatal to humans and all vertebrate animals, since it deprives the brain of oxygenated blood by way of severing the jugular vein and common carotid artery, while all other organs are deprived of the involuntary functions that are needed for the body to function. The term beheading refers to the act of deliberately decapitating a person, either as a means of murder or as an execution; it may be performed with an axe, sword, or knife, or by mechanical means such as a guillotine. An executioner who carries out executions by beheading is sometimes called a headsman. Accidental decapitation can be the result of an explosion, a car or industrial accident, improperly administered execution by hanging or other violent injury. The national laws of Saudi Arabia and Yemen permit beheading. Under Sharia, which exclusively applies to Muslims, beheading is also a legal punishment in Zamfara State, Nigeria. Cases of decapitation by suicidal hanging, suicide by train decapitation and by guillotine have been documented.

Less commonly, decapitation can also refer to the removal of the head from a body that is already dead. This might be done to take the head as a trophy, as a secondary stage of an execution by hanging, for public display, to make the deceased more difficult to identify, for cryonics, or for other, more esoteric reasons.