Decapitation is quickly fatal to humans and most animals as brain death occurs within minutes without circulating oxygenated blood. However, some animals and insects such as cockroaches can survive decapitation, and die not because of it, but because of starvation.
The British officer John Masters recorded in his autobiography that Pathan women in the North-West Frontier Province (1901–1955) of British India (now modern day Pakistan) during the Anglo-Afghan Wars would behead and castrate non Muslim soldiers who were captured, like British and Sikhs.
In Japan, decapaiation was historically performed as the second step in seppuku (ritual suicide by disembowelment). After the victim had sliced his own abdomen open, another warrior would strike his head off from behind with a katana to hasten death and to reduce the suffering. The blow was expected to be precise enough to leave intact a small strip of skin at the front of the neck—to spare invited and honored guests the indelicacy of witnessing a severed head rolling about, or towards them; such an event would have been considered inelegant and in bad taste.
The type of "beheading" practiced by Al Qaeda and similar groups differs from traditional judicial beheading. Traditional beheading is done quickly, with a massive steel blade, which cuts through the neck from the back, first severing the spinal column, then cutting the four large blood vessels, the trachea, and the esophagus. Unconsciousness is nearly instantaneous, and brain death occurs shortly thereafter. Terrorist-style beheading is reversed: using a rather small knife, first the killer cuts the throat, severing the carotid arteries and jugular veins, the trachea, and the esophagus, causing the victim to bleed out within a minute; then the spine is slowly severed by an instrument that is not really massive enough for the job (acceptable substitutes would include a machete, a butcher's cleaver, or a more traditional sword or axe). The first half of this procedure follows the method for Islamic ritual slaughter of food animals. The second half follows no clear precedent.
http://en.wikipedia.org/wiki/Decapitation
The British officer John Masters recorded in his autobiography that Pathan women in the North-West Frontier Province (1901–1955) of British India (now modern day Pakistan) during the Anglo-Afghan Wars would behead and castrate non Muslim soldiers who were captured, like British and Sikhs.
In Japan, decapaiation was historically performed as the second step in seppuku (ritual suicide by disembowelment). After the victim had sliced his own abdomen open, another warrior would strike his head off from behind with a katana to hasten death and to reduce the suffering. The blow was expected to be precise enough to leave intact a small strip of skin at the front of the neck—to spare invited and honored guests the indelicacy of witnessing a severed head rolling about, or towards them; such an event would have been considered inelegant and in bad taste.
The type of "beheading" practiced by Al Qaeda and similar groups differs from traditional judicial beheading. Traditional beheading is done quickly, with a massive steel blade, which cuts through the neck from the back, first severing the spinal column, then cutting the four large blood vessels, the trachea, and the esophagus. Unconsciousness is nearly instantaneous, and brain death occurs shortly thereafter. Terrorist-style beheading is reversed: using a rather small knife, first the killer cuts the throat, severing the carotid arteries and jugular veins, the trachea, and the esophagus, causing the victim to bleed out within a minute; then the spine is slowly severed by an instrument that is not really massive enough for the job (acceptable substitutes would include a machete, a butcher's cleaver, or a more traditional sword or axe). The first half of this procedure follows the method for Islamic ritual slaughter of food animals. The second half follows no clear precedent.
http://en.wikipedia.org/wiki/Decapitation