The fight-or-flight response is a physiological reaction that occurs in response to a perceived harmful event, attack, or threat to survival. It was first described by ...Fight-or-flightresponseFromWikipedia,thefreeencyclopediaJumptonavigationJumptosearchPhysiologicalreactiontoaperceivedthreatorharmfuleventForotheruses,seeFightorFlight.DogandcatshowingacutestressresponsesThefight-or-flightresponse(alsocalledhyperarousalortheacutestressresponse)isaphysiologicalreactionthatoccursinresponsetoaperceivedharmfulevent,attack,orthreattosurvival.[1]ItwasfirstdescribedbyWalterBradfordCannon.[a][2]Histheorystatesthatanimalsreacttothreatswithageneraldischargeofthesympatheticnervoussystem,preparingtheanimalforfightingorfleeing.[3]Morespecifically,theadrenalmedullaproducesahormonalcascadethatresultsinthesecretionofcatecholamines,especiallynorepinephrineandepinephrine.[4]Thehormonesestrogen,testosterone,andcortisol,aswellastheneurotransmittersdopamineandserotonin,alsoaffecthoworganismsreacttostress.[5]Thehormoneosteocalcinmightalsoplayapart.[6][7]Thisresponseisrecognisedasthefirststageofthegeneraladaptationsyndromethatregulatesstressresponsesamongvertebratesandotherorganisms.[8]Contents1Physiology1.1Autonomicnervoussystem1.1.1Sympatheticnervoussystem1.1.2Parasympatheticnervoussystem1.2Reaction1.3Functionofphysiologicalchanges2Emotionalcomponents2.1Emotionregulation2.2Emotionalreactivity3Cognitivecomponents3.1Contentspecificity3.2Perceptionofcontrol3.3Socialinformationprocessing4Otheranimals4.1Evolutionaryperspective4.2Examples4.3Varietiesofresponses5Seealso6Notes7References8Furtherreading9ExternallinksPhysiology[edit]Autonomicnervoussystem[edit]Seealso:AutonomicnervoussystemTheautonomicnervoussystemisacontrolsystemthatactslargelyunconsciouslyandregulatesheartrate,digestion,respiratoryrate,pupillaryresponse,urination,andsexualarousal.Thissystemistheprimarymechanismincontrolofthefight-or-flightresponseanditsroleismediatedbytwodifferentcomponents:thesympatheticnervoussystemandthepara