Editing Decapitation (section)

== Physiological aspects ==

===Physiology of death by decapitation===
Decapitation is quickly fatal to [[humans]] and most [[animals]]. Unconsciousness occurs within seconds without circulating oxygenated blood ([[brain ischemia]]).<ref>{{cite journal|last=Turner|first=Matthew D.|title=The Most Gentle of Lethal Methods: The Question of Retained Consciousness Following Decapitation.|journal=Cureus|volume=15|issue=1|date=2023|pages=e33830 |doi=10.7759/cureus.33830 |doi-access=free |pmid=36819446 |pmc=9930870 }}</ref> Cell death and irreversible [[brain damage]] occurs after 3–6 minutes with no oxygen, due to [[excitotoxicity]]. Some anecdotes suggest more extended persistence of human consciousness after decapitation,<ref>Gabriel Beaurieux, writing in 1905, quoted in {{cite book |last=Kershaw |first=Alister |title=A History of the Guillotine |year=1958 |publisher=John Calder |isbn=978-1-56619-153-1}}, cited by {{cite web |url=http://thechirurgeonsapprentice.com/2012/08/13/losing-ones-head-a-frustrating-search-for-the-truth-about-decapitation/ |title=Losing One's Head: A Frustrating Search for the 'Truth' about Decapitation |work=The Chirurgeon's Apprentice |access-date=8 April 2014 |archive-url=https://web.archive.org/web/20140409013245/http://thechirurgeonsapprentice.com/2012/08/13/losing-ones-head-a-frustrating-search-for-the-truth-about-decapitation/ |archive-date=9 April 2014 }}</ref> but most doctors consider this unlikely and consider such accounts to be misapprehensions of reflexive twitching rather than deliberate movement, since deprivation of oxygen must cause nearly immediate coma and death ("[Consciousness is] probably lost within 2–3 seconds, due to a rapid fall of intracranial [[perfusion]] of blood").<ref>{{cite journal |last1=Hillman |first1=Harold |date=27 October 1983 |title=An Unnatural Way to Die |journal=New Scientist |pages=276–278 }} Cited in {{cite web |url=http://science.howstuffworks.com/life/inside-the-mind/human-brain/10-brain-myths6.htm |title=Top 10 Myths About the Brain |author=Shanna Freeman |work=How Stuff Works |page=5: Your Brain Stays Active After You Get Decapitated |access-date=8 April 2014 |date=17 September 2008 |archive-date=6 April 2014 |archive-url=https://web.archive.org/web/20140406215054/http://science.howstuffworks.com/life/inside-the-mind/human-brain/10-brain-myths6.htm |url-status=live }}</ref>

A laboratory study testing for humane methods of euthanasia in awake animals used EEG monitoring to measure the time duration following decapitation for rats to become fully unconscious, unable to perceive distress and pain. It was estimated that this point was reached within 3–4 seconds, correlating closely with results found in other studies on rodents (2.7 seconds, and 3–6 seconds).<ref>{{cite journal |last1=van Rijn |first1=Clementina M. |title=Decapitation in Rats: Latency to Unconsciousness and the 'Wave of Death' |journal=PLOS ONE |date=27 January 2011 |volume=6 |issue=1 |pages=e16514 |doi=10.1371/journal.pone.0016514 |pmid=21304584 |pmc=3029360 |bibcode=2011PLoSO...616514R |doi-access=free }}</ref><ref>{{cite journal |last1=Derr |first1=Robert F. |title=Pain perception in decapitated rat brain |journal=Life Sciences |date=29 August 1991 |volume=49 |issue=19 |pages=1399–1402 |doi=10.1016/0024-3205(91)90391-n|pmid=1943446 }}</ref><ref>{{cite journal |last1=Holson |first1=R. Robert |title=Euthanasia by decapitation: Evidence that this technique produces prompt, painless unconsciousness in laboratory rodents |journal=Neurotoxicology and Teratology |date=6 January 1992 |volume=14 |issue=4 |pages=253–257 |doi=10.1016/0892-0362(92)90004-t|pmid=1522830 |bibcode=1992NTxT...14..253H }}</ref> The same study also suggested that the massive wave which can be recorded by EEG monitoring approximately one minute after decapitation ultimately reflects brain death. Other studies indicate that electrical activity in the brain has been demonstrated to persist for 13 to 14 seconds following decapitation (although it is disputed as to whether such activity implies that pain is perceived),<ref>{{cite journal |last1=Hawkins |first1=Penny |title=A Good Death? Report of the Second Newcastle Meeting on Laboratory Animal Euthanasia |journal=Animals |date=23 August 2016 |volume=6 |issue=50 |page=50 |pmc=5035945 |pmid=27563926 |doi=10.3390/ani6090050 |doi-access=free }}</ref> and a 2010 study reported that decapitation of rats generated responses in EEG indices over a period of 10 seconds that have been linked to [[nociception]] across a number of different species of animals, including rats.<ref>{{cite journal |last1=Kongara |first1=Kavitha |s2cid=24006386 |title=Electroencephalographic evaluation of decapitation of the anesthetized rat |journal=Laboratory Animals |date=January 2014 |volume=48 |issue=1 |pages=15–19 |url=https://www.researchgate.net/publication/259456691 |doi=10.1177/0023677213502016 |pmid=24367032 |access-date=18 March 2019 |archive-date=8 June 2024 |archive-url=https://web.archive.org/web/20240608031120/https://www.researchgate.net/publication/259456691_Electroencephalographic_evaluation_of_decapitation_of_the_anesthetized_rat |url-status=live }}</ref>

Some animals (such as [[cockroach]]es) can survive decapitation and die not because of the loss of the head directly, but rather because of [[starvation]].<ref>{{cite web |url=http://www.scientificamerican.com/article.cfm?id=fact-or-fiction-cockroach-can-live-without-head |title=Fact or Fiction?: A Cockroach Can Live without Its Head |first=Charles |last=Choi |website=[[Scientific American]] |access-date=25 February 2017 |archive-date=27 December 2013 |archive-url=https://web.archive.org/web/20131227211121/http://www.scientificamerican.com/article.cfm?id=fact-or-fiction-cockroach-can-live-without-head |url-status=live }}</ref> A number of other animals, including [[snake]]s, and [[turtle]]s, have also been known to survive for some time after being decapitated, as they have slower metabolisms and their [[nervous system]]s can continue to function at some capacity for a limited time even after connection to the brain is lost, responding to any nearby stimulus.<ref>{{cite web |last1=Leahy |first1=Stephen |title=Decapitated Snake Head Nearly Kills Man – Here's How |url=https://news.nationalgeographic.com/2018/06/texas-man-bit-decapitated-rattlesnake-venom-animals/ |archive-url=https://web.archive.org/web/20180607193042/https://news.nationalgeographic.com/2018/06/texas-man-bit-decapitated-rattlesnake-venom-animals/ |archive-date=7 June 2018 |website=[[National Geographic]] |access-date=7 August 2018 |date=7 June 2018}}</ref><ref>{{cite news |title=AL man battles headless rattlesnake |url=http://www.wsfa.com/story/38376061/video-alabama-man-battles-headless-rattlesnake |work=WSFA 12 News |access-date=7 August 2018 |date=7 June 2018 |archive-date=8 June 2024 |archive-url=https://web.archive.org/web/20240608031050/https://www.wsfa.com/story/38376061/video-alabama-man-battles-headless-rattlesnake/ |url-status=live }}</ref> In addition, the bodies of [[Mike the Headless Chicken|chicken]]s and turtles may continue to move temporarily after decapitation.<ref>{{cite web |last1=Sjøgren |first1=Kristian |title=Why do headless chickens run? |url=http://sciencenordic.com/why-do-headless-chickens-run |website=ScienceNordic |access-date=7 August 2018 |date=13 February 2014 |archive-date=7 August 2018 |archive-url=https://web.archive.org/web/20180807063645/http://sciencenordic.com/why-do-headless-chickens-run |url-status=live }}</ref>

Although [[head transplant]]ation by the reattachment of blood vessels has seen some very limited success in animals,<ref>{{cite book|last=Roach |first=Mary |year=2004 |title=Stiff: The Curious Lives of Human Cadavers |publisher=[[W. W. Norton & Company]] |isbn=978-0-393-32482-2 |page=208 |title-link=Stiff: The Curious Lives of Human Cadavers}}</ref> a fully functional reattachment of a severed human head (including repair of the [[spinal cord]], muscles, and other critically important tissues) is not likely.{{citation needed|date=April 2025}}