ENDOCRINEPHYSIOLOGY内分泌生理 DepartmentofPhysiology MedicalSchool SoochowUniversity Suzhou215007 ChinaE mail wangguoqing Tel 0512 62096158 13506212030 ENDOCRINEGLANDS BASICPRINCIPLESANDORGANIZATION DefinitionoftheEndocrineSystemEndocrineandnervoussystemscoordinatecomplexbodyfunctions Classicdistinctionbetweenthesetwoisthattheendocrinesystemcommunicatestodistanttissuesthroughblood carriedchemicalswhilethenervoussystemcommunicatestoadjacenttissuebylocalchemicalrelease neurotransmitter 神经递质 Organsoftheendocrinesystemincludeadrenal gonads hypothalamus pancreas parathyroid pituitary thyroid aswellasothers suchastheheart kidney andgastrointestinaltract Distinctionbetweenthesetwocommunicationsystems NervoussystemandEndocrinesystem Nervesintheposteriorpituitaryreleaseoxytocin 催产素 andantidiuretichormone 抗利尿激素 whichactonthebreastandkidneys respectively Nervesreleaseepinephrinefromtheadrenalmedulla whichactsontheheart skeletalmuscle andtheliver Nervesofthehypothalamussecretechemicals releasinghormones thatactontheanteriorpituitarytocausehormonerelease Therefore thedefinitionoftheendocrinesystemshouldalsoincludesuchneuroendocrinesystems Generaldefinitionforhormone Classicdefinition ByStarlingandBayliss Thehormonesarechemicalsubstancesproducedbyspecializedtissuesandsecretedintoblood inwhichtheyarecarriedtotargetorgansandtriggersspecificbiologicalfunctions Limitsofclassicdefinition SpecializedtissuesforhormonesynthesisBloodforhormonedistributionAseparatetargetorganBroaderdefinitionAhormoneisachemicalnon nutrient intercellularmessengerthatiseffectiveatmicromolarconcentrationsorless highefficiency LivingthingsthatcansecretehomonesMulticelluar Animal Plant InsectandSomefungi ConcentrationPeptidalhormoneinanimalblood10 12 10 10M Steroidhormoneinanimalblood10 10 10 8M EndocrinecellandTargetCell tissueandorgan PowerfulBiologicalEffectsMetabolicandPhysiologicaleffect Afurtherunderstandingonhormones TABLEENDOCRINEGLANDS HORMONESSECRETED ANDTISSUEEFFECTENDOCRINEGLANDHORMONESSECRETEDTISSUEEFFECTHypothalamusCorticotropin releasinghormone CRH StimulatesACTHsecretionDopamineInhibitsprolactinsecretionGonadotropin releasinghormone GnRH StimulatesLHandFSHsecretionGrowth hormonereleasinghormone GHRH StimulatesGHsecretionSomatostatinInhibitsGHsecretionThyrotropin releasinghormone TRH StimulatesTSHandprolactinsecretionAnteriorAdrenocorticotropichormone ACTH Stimulatessynthesis secretionpituitaryofcortisol androgensandaldosteroneFollicle stimulatinghormone FSH Stimulatesspermmaturation developmentofovarianfolliclesGrowthhormone GH StimulatesproteinsynthesisandgrowthLuteinizinghormone LH Stimulatestestosterone estrogen progesteronesynthesis stimulatesovulationMelanocyte stimulatinghormone MSH StimulatesmelaninsynthesisProlactinStimulatesmilkproductionThyroid stimulatinghormone TSH Stimulatesthyroidhormonesynthesis secretionPosteriorOxytocinStimulatesmilkejectionandPituitaryuterinecontractionAntidiuretichormone ADH StimulatesrenalwaterreabsorptionThyroidTriiodothyronine T3 andStimulatesgrowth oxygenthyroxine T4 consumption heatproduction metabolism nervoussystemdevelopmentContinuednext TABLEENDOCRINEGLANDS HORMONESSECRETED ANDTISSUEEFFECT continued ENDOCRINEGLANDHORMONESSECRETEDTISSUEEFFECTThyroidCalcitoninDecreasesbloodCaconcentrationParathyroidParathyroidhormone PTH IncreasesbloodCaconcentrationAdrenalcortexCortisolIncreasesglucosesynthesis mediates stress responseAldosteroneIncreasesrenalreabsorptionofNa secretionofK andH AndrogensSimilartotestosteronebutweakerAdrenalmedullaEpinephrineStimulatesfatandcarbohydratemetabolismPancreasInsulinDecreasesbloodglucoselevels anaboliceffectsonlipidandproteinmetabolismGlucagonIncreasesbloodglucoselevelsTestesTestosteroneStimulatesspermatogenesisandsecondarysexcharacteristicsOvariesEstradiolStimulatesgrowth developmentoffemalereproductivesystemandbreasts follicularphaseofmenstrualcycle prolactinsecretion andmaintainspregnancyProgesteroneLutealphaseofmenstrualcycleandmaintainspregnancyCorpusluteumEstradiolandprogesteroneSeeabovePlacentaHumanchorionicgonadotropin hCG Stimulatesestrogen progesteronesynthesisbycorpusluteumHumanplacentallactogen hPL ActslikeGHandprolactinduringpregnancyEstriolActslikeestradiolProgesteroneSeeaboveThistableliststhemajorendocrineorgans thehormoneseachorgansecretes andthemajortissueeffectofthehormone ENDOCRINESYSTEM ChemicalNatureofHormones Classicdefinitionofahormoneisachemicalproducedbyanorganinasmallamountthatisreleasedintothebloodstreamtoactoncellsinadistanttissue Thisdefinitionneedstobeexpandedtoincludechemicalsthathaveparacrineandautocrinefunctions Hormonesaredividedintofourgroupsbasedonchemicalstructure 1 amines 胺类 comefromtheaminoacidtyrosine 2 peptides 肽类 lessthan20aminoacids 3 smallproteins 小蛋白 morethan20aminoacids 4 steroids 类固醇 comefromcholesterol Definitionofthehormones Telecrinesignals Neurocrinesignals Definitionofthehormones TABLEMAJORHORMONESGROUPEDBYCHEMICALSTRUCTUREAMINESPEPTIDESPROTEINSSTEROIDSDopamineAntidiureticAdrenocorticotropicAldosteronehormone ADH Hormone