Exam Notes On Physiology And Anatomy; Hypothalamus

HypothalamusIntroduction:Itisadiencephalicstructure.Itinjustsituatedbelowthalamusintheventralpartgdiencephalon..Itinformedbygroupsynuclei,scatteredinthewallsandfloorgthirdventricle.Itextendsfromopticchiasmatomamillanybody.NucleigHypothalamus:ThreegroupsinAnteriororpreopticgroup(asMiddleortuberalgroup(3)PosteriorormammillarygroupFunctionsgHypothalamus:Itinimportantforhomeostasis.Itregulatesmanyvitalfunctionsgthebodylikeendocrinefunctions,hunger,thirst,emotions,sexualfunctionsetc.Secretiongposteriorpituitaryhormones.ControlgAnteriorpituitary.ControlgAdrenalCortesebyACTHControlgAdrenalmedullabyemotionalstimuli.RegulationgAutonomicNervousSystem.RegulationogHeartRate.RegulationgBloodPressure--cisHeatlosscenterinpreopticnucleusRegulationgBodytemperature-IgAnt.hypothalamus\-disHeatgaincenterinposteriorRegulationgHunger&foodintake.hypothalamusisfeedingcenternucleus-ciiisatietycenterRegulationywaterbalance.cisThirstmechanismdisADHmechanismRegulationgsleepandWa ke f u l n e s sRoleinbehaviourandemotionalchanges.RegulationgsexualfunctionRoleinresponsetosmell.RoleinCircadianrhythm.MechanismgRegulationgfoodIntake:Feedingcenterandsatietycenterghypothalamusareresponsibleforregulationgappetiteandfoodintake.Thesecentersanregulatedby:IaiGlucostaticmechanism(b,Lipostalicmechanismcc,Peptidemechanism(d)HormonalmechanismcelThermostaticmechanism.(a)Glucoslak.cm#chamism:foodintakeIncin-stimulationgsatietycenterInhibitionybloodglucosefeedingcenter^/stoppagegfoodintakeflatter3hrs)Increaseinc-ActivationgNomoneyDecbloodappetitefeedingcenterinhibitiongglucosefeeding&satietycenter(b,Lipotm:Vo l u m eg-leptinreleasedEnterslepkAdiposetissuefbyadiposetissuehypothalamusinhibitsthefeedingcenterIstoppageLossYManyleptinreceptorsanLepRb9foodintakeAppetitepresentinmanynucleig-hypothalamus-cosPeplidetlechanismGhrelinsecretedinstimulatedfeedingcenterInc.appetitestomach&foodintake.(Duringfasting)Peptideswhichincreasesthefoodintake:whichdecreasesca)Ghrelinfoodintake:(biNeuropepledYca)Leptin(biPeptideYY(d,HormonalMechanism-:Inhibitfoodintake(i,somatostatinCixiPancreaticpolypeptideciisOxytocinl"cholecystkinin.ciii,Glucagon(e,ThermostalictlechanismTe m pisinverselyproportionaltobodytemp.Infever.foodintakeY,Exactcausenotknownbutitinsuggestedthatthepreopticthermoreceptorsmayactviafeedingcenter.MechanismgRegulationglalaterBalance:CIIThirsts:**(ItsADHMechanism:ECFIgntcnasedOsmolalityECFqandstellate,Suptraopkicnucleus(stimulated)IAotreleased-CausesRetentiongwaterviafacultativeReabsor-plionAppliedPhysiologyLesionghypothalamusoccursduetotumors,encephalitisandischemia.osymptomsdetectedan:(isDisturbanceinCarbohydrate&Fatmetabolism.ciiiDisturbanceinsleepduetolesioninmamiHarybody.ciii,DisturbanceinANS(inEmotionalmanifestations.canDisturbanceinsexualfunctionsduetolesioninmidhypothat-aimus.Onegmoreabovefeaturescanbecomeprominentandresultsinanygthem:cisDiabetesinsipidusciiiDystrophicadiposogenitale'sciii,KallmannSyndrome(inLaurence-Moon-Biedlsyndrome-callNarcolepsy.cutcataplexy.MedNotes(mednotes.in)