Classification
Thefirstlinkofthereflexarcistheperipheraldevicesurroundingthesensoryneuron.Itcomesfromtheoutsideworldorinsidethebodyandisthestimulusfeltbythereceptors,whichtransformsintolifeprocess.Accordingtothedistributionandfunctionofreceptors,itcanbedividedintothreecategories,namelyexternalreceptors,proprioceptorsandinternalreceptors.
Externalreceptorsaredistributedintheskin,mucousmembranes,visualorgansandhearingorgans,andfeelthestimulifromtheexternalenvironment,suchaspain,temperature,touch,pressure,light,soundandotherstimuli.
Theproprioceptorsarestimulatedbymuscles,tendons,joints,ligaments,andfasciatoproducepostureandmovementsensation.Thesensationsofexternalreceptorsandproprioceptorscomefromthebody,andaresometimescollectivelyreferredtoassomatosensory.
Theinternalreceptorsreceivevariousstimuli(mechanical,chemical,osmotic,etc.)oftheinternalorgansandbloodvessels,andarealsodividedintotwotypes:oneisthegeneralvisceralreceptorsthatacceptthegeneralsensationofinternalorgansandbloodvessels;theotherisSpecialvisceralreceptorsthatacceptsmellandtaste.
Reflexarc
Allactivitiesofthenervoussystemarerealizedbyreflection,thatis,thebodyrespondsappropriatelytointernalandexternalenvironmentalstimuliinatimelymanner.Reflexisdividedintotwotypes:unconditionedreflexandconditionedreflex.Theentirestructurethatperformsreflectioniscalledareflectionarc.Thereflexarcincludesfiveparts:receptors,sensoryneurons(afferentneurons),nervecenters(interneurons),efferentneurons(motorneurons)andeffectors.Thegreaterthenumberofneuronsformingthereflexarc,themorecomplexandcompletethesynapsesandtheadjustedinformationthatpassthrough.Theinterneurons(referredtoasoneormorebetweentheafferentneuronandtheefferentneuron)Aneuron)isveryimportant.Itcanstoreallkindsofinformationandreactaftermanytimesofanalysisandsynthesis.Thethinkingactivityofthehumancerebralcortexmaybetheextremelycomplexreflexactivityofalargenumberofinterneurons.