Fight-or-flight response, response to an acute threat to survival that is marked by physical changes, including nervous and endocrine changes, that prepare a ...Fight-or-flightresponseArticleMediaAdditionalInfoHomeScienceBiologyFight-or-flightresponsephysiologyPrintCiteverifiedCiteWhileeveryefforthasbeenmadetofollowcitationstylerules,theremaybesomediscrepancies.Pleaserefertotheappropriatestylemanualorothersourcesifyouhaveanyquestions.SelectCitationStyleMLAAPAChicagoManualofStyleCopyCitationShareShareSharetosocialmediaFacebookTwitterURLhttps://www.britannica.com/science/fight-or-flight-responseMoreGiveFeedbackExternalWebsitesFeedbackCorrections?Updates?Omissions?Letusknowifyouhavesuggestionstoimprovethisarticle(requireslogin).FeedbackTypeSelectatype(Required)FactualCorrectionSpelling/GrammarCorrectionLinkCorrectionAdditionalInformationOtherYourFeedbackSubmitFeedbackThankyouforyourfeedbackOureditorswillreviewwhatyou’vesubmittedanddeterminewhethertorevisethearticle.JoinBritannica'sPublishingPartnerProgramandourcommunityofexpertstogainaglobalaudienceforyourwork!ExternalWebsitesLearn.Genetics-GeneticScienceLearningCenter-TheFightorFlightResponseVerywellMind-HowtheFightorFlightResponseWorksWRITTENBYTheEditorsofEncyclopaediaBritannicaEncyclopaediaBritannica'seditorsoverseesubjectareasinwhichtheyhaveextensiveknowledge,whetherfromyearsofexperiencegainedbyworkingonthatcontentorviastudyforanadvanceddegree....SeeArticleHistoryAlternativeTitle:defensereactionFight-or-flightresponse,responsetoanacutethreattosurvivalthatismarkedbyphysicalchanges,includingnervousandendocrinechanges,thatprepareahumanorananimaltoreactortoretreat.Thefunctionsofthisresponsewerefirstdescribedintheearly1900sbyAmericanneurologistandphysiologistWalterBradfordCannon.autonomicnervoussystemSchematicrepresentationoftheautonomicnervoussystem,showingdistributionofsympatheticandparasympatheticnervestothehead,trunk,andlimbs.EncyclopædiaBritannica,Inc.Discoverhowthevariouspartsofthebrainplayakeyroleincontrollingthe