生物ch45hormones and the enrine systembody分泌到循环系统调节体内信息的化学信号

Ch45HormonesandtheEndocrineOverview:TheBody’sLong-DistanceAnimalhormonesarechemicalsignalsthataresecretedintothecirculatorysystemandcommunicateregulatorymessageswithintheHormonesreachallpartsofthebody,butonlytargetcellshavereceptorsforthathormoneInsectmetamorphosis变形isregulatedbyTwosystemscoordinatecommunicationthroughoutthebody:theendocrinesystemandTheendocrinesystemsecreteshormonesthatcoordinateslowerbutlonger-actingresponsesincludingreproduction,development,energymetabolismgrowthandbehavior内分泌较慢，调Thenervoussystemconveyshigh-speedelectricalsignalsalongspecializedcellscalledneuronsthesesignalsregulateothercells神经系FigureFigureConcept45.1:Hormonesandothersignalingmoleculesbindtotargetreceptors,triggeringspecificresponsepathways Endocrinesignalingisjustoneofseveralwaysthatinformationistransmittedbetweenanimal IntercellularThewaysthatsignalaretransmittedbetweenanimalcellsareclassifiedbytwocriteria按两个标准分类ThetypeofsecretingcellTheroutetakenbythesignalinreachingitstarget到达靶点的路径EndocrineHormonessecretedintoextracellularfluidsbyendocrinecellsreachtheirtargetsviatheEndocrinesignalingmaintainshomeostasis体内mediatesresponsestostimuli对刺激的反应regulatesgrowthdevelopment发育TypesofSecretedSignalingSecretedchemicalsignalsPheromonesEndocrinesignals(hormonesaresecretedintoextracellularfluidsandtravelviathebloodstream激素分泌到胞外，由血液递送全身Endocrineglands内分泌腺areductlessandsecretehormonesdirectlyintosurroundingfluidHormonesmediateresponsestoenvironmentalstimuliandregulategrowth,development,andParacrineandAutocrineLocalregulatorsaremoleculesthatactovershortdistances,reachingtargetcellssolelyby(如TGF-b；Wnt；Notch;EGF…)Inparacrinesignaling,thetargetcellslienearInautocrinesignalingthetargetcellisalsothesecretingcell自分泌信号，调节分泌细胞自身Figure EndocrineParacrineAutocrineSynapticandNeuroendocrineInsynapticsignaling,neuronsformspecializedjunctionswithtargetcells,calledsynapsesAtsynapses,neuronssecretemoleculescalledneurotransmittersthatdiffuseshortdistancesandbindtoreceptorsontargetcells.Neurotransmittersyaroleinsensation,memory,cognition,and Inneuroendocrinesignaling,specializedneurosecretorycellssecretemoleculescalledneurohormonesthattraveltotargetcellsviatheFigure

Synaptic

Exocrineglandshaveductsandsecretesubstancesontobodysurfacesorintobodycavitiesforexampletearducts)外分泌腺体有SignalingbyMembersofthesameanimalspeciessometimescommunicatewithpheromones,chemicalsthatarereleasedintotheenvironmentandusedtocommunicatewithotherindividualsinthespecies Pheromonesservemanyfunctions,includingmarkingtrailsleadingtofood通往食物的踪迹awiderangeoffunctionsthatincludedefiningterritories领地warningofpredators警戒,andattractingpotentialmates吸引配偶FigureEndocrineTissuesandInsometissues,endocrinecellsaregroupedtogetherinductlessorganscalledendocrineglands内分泌细胞组成无管道的 Endocrineglandssecretehormonesdirectlyintosurroundingfluid直接分泌到胞外Thesecontrastwithexocrineglandswhichhaveductsandwhichsecretesubstancesontobodysurfacesorintocavities和外分泌腺不同Figure45.4 Majorendocrineglands:Hypothalamus下丘脑PinealglandPituitaryglandThyroidglandParathyroidglands(behindthyroid甲状旁腺(atopkidneysOvaries(female)

endocrinecells:Heart心脏Liver肝脏Stomach胃KidneysChemicalClassesofThreemajorclassesofmoleculesfunctionashormonesinvertebratesPolypeptides(proteinsandAminesderivedfromaminoacids来源于氨基酸SteroidhormonesLipid-solublehormones(steroidhormonespasseasilythroughcellmembranes,whilewater-solublehormones(polypeptidesandaminesdonot脂溶性的激素可以轻易穿过细胞膜Thesolubilityofahormonecorrelateswiththelocationofreceptorsinsideoronthesurfaceoftargetcells可溶性的激素和细胞表面受体结合Figure

0.8Insulin胰岛 Waterandlipidsolublehormonesdifferintheirpathsthroughabody体内传递途径不同Water-solublehormonesaresecretedbyexocytosis,travel lyinthebloodstreamandbindtocell-surfacereceptors水溶性的直接胞外Lipid-solublehormonesdiffuseacrosscellmembranes,travelinthebloodstreamboundtotransportproteins,anddiffusethroughthemembraneoftargetcells脂溶性的扩散出细胞膜，HormoneReceptorLocation:ScientificInthe1960s,researchersstudiedtheaccumulationofradioactivesteroidhormonesinrattissueThesehormonesaccumulatedonlyintargetcellsthatwereresponsivetothehormonesTheseexperimentsledtothehypothesisthatreceptorsforthesteroidhormonesarelocatedinsidethetargetcellsFurtherstudieshaveconfirmedthatreceptorsforlipid-solublehormonessuchassteroidsarelocatedinsidecellsResearchershypothesizedthatreceptorsforwater-solublehormoneswouldbelocatedonthecellsurfaceTheyinjectedawater-solublehormoneintothetissuesofThehormonetriggeredaresponseonlywhenitwasallowedtobindtocellsurfacereceptorsThisconfirmedthatwater-solublereceptorswereonthecellsurface

Signal

Signal

PathwayforWater-SolubleBindingofahormonetoitsreceptorinitiatesasignaltransductionpathwayleadingtoresponsesinthecyto sm,enzymeactivation,orachangeingeneexpression激素和受体结合Signalingbyanyofthesehormonesinvolvesthreekeyevents:信号转导步骤ReceptionSignaltransductionResponseAnimation:Water-SolubleRight-clickslide/ Thehormoneepinephrinehasmultipleeffectsinmediatingthebody’sresponsetoshort-termstress肾上腺素对短期压力有多种反应Epinephrinebindstoreceptorsonthe membraneoflivercells和肝的受体结合Thistriggersthereleaseofmessengermoleculesthatactivateenzymesandresultinthereleaseofglucoseintothebloodstream刺激G

Gprotein-coupled

G

Gprotein-coupled

InhibitionofPromotionof

PathwayforLipid-SolubleTheresponsetoalipid-solublehormoneisusuallyachangeingeneexpression脂溶通常直接导致Steroids,thyroidhormones,andthehormonalformofvitaminDentertargetcellsandbindtoproteinreceptorsinthecyto smornucleus固醇，甲状腺激素等进入靶细Protein-receptorcomplexesthenactastranscriptionfactorsinthenucleus,regulatingtranscriptionofspecificgenes蛋白和受体复合体进入细胞核，作为转录因子调节特Animation:Lipid-SolubleRight-clickslide/

for

MultipleEffectsofThesamehormonemayhavedifferenteffectsontargetcellsthathave同一激素在不同靶细胞作用DifferentreceptorsforthehormoneDifferentsignaltransductionpathwaysFigure

Samereceptorsbutdifferentintracellularproteins(notshown)

andglucoseisreleasedfromcell.

(a)Livercell (b)Skeletalmusclebloodvessel

(c)IntestinalbloodSignalingbyLocalLocalregulatorsaresecretedmoleculesthatlinkneighbouringcellsordirectlyregulatethesecretingcell局部调节素调节附近细胞或者分泌TypesoflocalCytokines细胞因子andgrowthfactors生长因Nitricoxide(NO) Growthfactors生长因子proteinspolypeptidesthatstimulatecellExample:nervegrowthfactor(NGF)affectscertainembryoniccells,develo bloodcells,andotherkindsofcellsNitricoxideThoughagas,NOisanimportantlocalWhensecretedbyneurons,itactsasaWhensecretedbywhitebloodcells,itkillsbacteriaandcancercells由白细胞分泌则可以Andwhensecretedbyendothelialcells,itdilatesthewallsofbloodvessels由血管内皮Viagra modifiedfattyacidsPGssecretedbythe centastimulateuterinecontractionsduringchildbirth.胎盘分泌 OtherPGs yaroleininfl tion炎症反Intheimmunesystem,prostaglandinspromotefeverand tionandintensifythesensationofProstaglandinshelpregulateaggregationofets,anearlystepinformationofbloodclotsRoleinbloodflowtothelungs控制血流进入ProstaglandinE、prostaglandinCoordinationofNeuroendocrineandEndocrineSignalingTheendocrineandnervoussystemsgenerallyactcoordina ytocontrolreproductionandForexampleinlarvaeofbutterfliesandmoths,thesignalsthatdirectmoltingoriginateinthebrain蝴蝶和蛾子幼虫蜕皮信号来源于脑部Ininsects,moltinganddevelopmentarecontrolledbyacombinationofhormonesAbrainhormone(PTTH前胸腺促泌素)stimulatesreleaseofecdysteroid蜕皮激素fromtheprothoracicglands前胸腺retentionoflarvalcharacteristicsEcdysone蜕promotesmoltinginthepresenceofjuvenilehormone)anddevelopment(intheabsenceofjuvenilehormone)ofadultcharacteristics

Corporaallata咽侧体

Concept45.2:Feedbackregulationandantagonistichormonepairsarecommoninendocrinesystems反馈调控和拮抗激素HormonesareassembledintoregulatorySimpleHormoneHormonesarereleasedfromanendocrinecell,travelthroughthebloodstream,andin ctwithspecificreceptorswithinatargetcelltocauseaphysiologicalresponse激素由内分泌细胞分泌，Forexamplethereleaseofacidiccontentsofthestomachintotheduodenumstimulatesendocrinecellstheretosecretesecretin肠促胰液素胃的酸Thiscausestargetcellsinthepancreasaglandbehindthestomach,toraisethepHintheduodenum导致胰腺中靶细胞升高十二指肠的pHFigure

LowpH

Scellsofduodenumsecretethehormonesecretin().

BicarbonateInasimpleneuroendocrinepathway,thestimulusisreceivedbyasensoryneuronwhichstimulatesaneurosecretorycell简单的神经内分泌通路:感觉Theneurosecretorycellsecretesaneurohormone,whichentersthebloodstreamandtravelstotargetcells神经分泌细胞分泌神经Figure

PositivePositiveBlood

Posteriorpituitarysecretestheoxytocin( SmoothmuscleinMilkAnegativefeedback负反loopinhibitsaresponsebyreducingtheinitialstimulusthuspreventingexcessivepathwayactivityPositivefeedback正反馈rein sastimulustoproduceanevengreaterresponseForexample,inm lsoxytocincausesthereleaseofmilk,causinggreatersucklingbyoffspringwhichstimulatesthereleaseofmoreoxytocin催产素InsulinandGlucagon:ControlofBloodInsulin胰岛素(decreasesbloodglucose)andglucagon(increasesbloodglucose)areantagonistichormonesthathelpmaintainglucosehomeostasisThepancreashasclustersofendocrinecellscalledpancreaticisletswithalphacellsthatproduceglucagonandbetacellsthatproduceFigureBodycellstakeupmore

Betacellsofintothelevel

Livertakesupglucoseandstoresitas

Bloodglucoselevelrises(forinstance,aftereatingacarbohydrate-richmeal).Bloodglucoselevellevelrises.

Bloodglucoselevel ameal).Liverbreaksandreleasesglucoseintotheblood.

Alphacellsofpancreasreleaseglucagonintotheblood.TargetTissuesforInsulinandInsulinreducesbloodglucoselevelsPromotingthecellularuptakeofglucose提 Slowingglycogenbreakdownintheliver减Promotingfatstoragenotbreakdown增强GlucagonincreasesbloodglucoselevelsStimulatingconversionofglycogentoglucoseintheliver增加糖原分解Stimulatingbreakdownoffatandproteinintoglucose增加脂肪和蛋白分解成葡萄糖DiabetesDiabetesmellitus isperhapsthebest-knownendocrinedisorderItiscausedbyadeficiencyofinsulinoradecreasedresponsetoinsulinintargettissuesItismarkedbyelevatedbloodglucoselevels血TypeIdiabetesmellitus(insulin-dependent)isanautoimmunedisorderinwhichtheimmunesystemdestroyspancreaticbetacellsI型糖尿TypeIIdiabetesmellitus(non-insulin-dependent)involvesinsulindeficiencyorreducedresponseoftargetcellsduetochangeininsulinreceptorsII型 Concept45.3:ThehypothalamusandpituitaryarecentraltoendocrineregulationEndocrinepathwaysaresubjecttoregulationbythenervoussystem,includingthebrainCoordinationofEndocrineandNervousSystemsinVertebratesThehypothalamus下丘receivesinformationfromthenervoussystemandinitiatesresponsesthroughtheendocrinesystemAttachedtothehypothalamusisthepituitaryglandcomposedoftheposteriorpituitary垂体后叶andanteriorpituitary垂体前叶Theposteriorpituitary垂体后叶storesandsecreteshormonesthataremadeinthe Theanteriorpituitarymakesandreleaseshormonesunderregulationofthehypothalamus在下丘脑控制下分泌激素Adenohypophysis腺垂体Figure

glandSpinalcord

Thalamus丘脑Hypothalamus下丘脑gland垂体

ThetwohormonesreleasedfromtheposteriorpituitaryactdirectlyonnonendocrinetissuesOxytocin催产素inducesuterinecontractionsandregulatesmilksecretionbythem ryglandsSucklingsendsamessagetothehypothalamusviathenervoussystemtoreleaseoxytocin,whichfurtherstimulatesthemilkglandsThisisanexampleofpositivefeedback,wherethestimulusleadstoanevengreaterresponsewaterreabsorptioninthekidneysregulatesphysiologyandbehaviorFigure

cellsofthe

uterinemusclesAnteriorPituitaryHormoneproductionintheanteriorpituitaryiscontrolledbyreleasingandinhibitinghormonesfromthehypothalamus前叶激素被下丘脑的分泌或者抑制激素调节Forexample,prolactin-releasinghormone催乳素释放激素fromthehypothalamusstimulatestheanteriorpituitarytosecreteprolactin(PRL)催乳素,whichhasaroleinmilkproductionForexampletheproductionofthyrotropinreleasinghormone促甲状腺激素释放激素(TRH)inthehypothalamusstimulatessecretionofthethyroidstimulatinghormone甲狀腺刺激素(TSH)fromtheanteriorpituitaryFigureFSH促 NontropiceffectsNontropicandtropicGH生长激素 releasingand

cellsofthePortaloftheanterior FSHand

otherTableTableThyroidRegulation:AHormoneCascadeAhormonecanstimulatethereleaseofaseriesofotherhormones,thelastofwhichactivatesanonendocrinetargetcellthisiscalledahormonecascadepathway激素路Thereleaseofthyroidhormoneresultsfromahormonecascadepathwayinvolvingthehypothalamus,anteriorpituitary,andthyroidgland甲状腺激素分泌受包括下丘脑， Hormonecascadepathwaystypicallyinvolvenegativefeedback激素级 Figure

SensoryNeurosecretorycellBloodEndocrinecell

hormone Anteriorpituitarysecreteshormone(TSH,alsoknownasthyrotropinThyroidglandsecretesthyroidhormone(T3andT4).BodyFigure

SensoryneuronNeurosecretoryReleasingBloodAnterior

hormone(TRH Anteriorpituitarysecreteshormone(TSH,alsoknownasthyrotropin).Figure

NegativeNegativeEndocrine

hormone(TSH,alsoknownasthyrotropin).Thyroidglandsecretesthyroidhormone(T3andT4BodytissuesDisordersofThyroidFunctionandHypothyroidism甲状腺功能减退,toolittlethyroidfunctioncanproducesymptomssuchWeightgain,lethargy,coldproductionofthyroidhormone,canleadtoHightemperature,sweating,weightloss,irritabilityandhighbloodpressureMalnutritioncanalterthyroidfunction Gravesdisease毒性弥漫性甲状腺肿aformofhyperthyroidismcausedbyautoimmunity,istypifiedbyprotrudingeyes自身免疫导致的一种ThyroidhormonereferstoapairofTriiodothyronin(T3),withthreeiodineThyroxine(T4)withfouriodineInsufficientdietaryiodineleadstoanenlargedthyroidglandcalledagoiter碘摄取不足可能导FigureLowleveliodine

HighleveliodineEvolutionofHormoneOverthecourseofevolutionthefunctionofagivenhormonemaydivergebetweenspeciesForexample,thyroidhormoneysaroleinmetabolismacrossmanylineages,butinhastakenonauniquefunctionstimulatingtheresorptionofthetadpoletailduringmetamorphosis青蛙的甲状腺素促进变形Prolactin催乳激素alsohasabroadrangeofactivitiesinvertebratesFigureAdultregulatesskincolorinamphibians,fish,andreptilesbycontrollingpigmentdistributioninmelanocytes调节黑色素分布调节体色Inm ls,MSH ysadditionalrolesinhungerandmetabolisminadditiontoTropicandNontropicAtropichormoneregulatesthefunctionofendocrinecellsorglands促激素调节内分泌细ThreeprimarilytropichormonesFollicle-stimulatinghormone(FSH)促 Luteinizinghormone(LH) Growthhormone(GH)issecretedbytheanteriorpituitaryglandandhastropicandItpromotesgrowthdirectlyandhasdiverseItstimulatesproductionofgrowthfactorsAnexcessofGHcancausegigantism巨人症,whilealackofGHcancausedwarfism侏儒症Concept45.4:Endocrineglandsrespondtodiversestimuliinregulatinghomeostasis,development,andbehaviorEndocrinesignalingregulateshomeostasis,development,andbehavior内分泌信号调节体ParathyroidHormoneandVitaminD:ControlofBloodCalciumTwoantagonistichormonesregulatethehomeostasisofcalcium(Ca2+inthebloodof ls两种拮抗激素调节体内钙离子平衡Parathyroidhormone(PTH)甲状旁腺素isreleasedbytheparathyroidglands甲状旁腺分Calcitonin降钙isreleasedbythethyroidgland甲状腺分泌的降钙素uptakein

vitamin Stimulatesuptakeinlevel

Ca2releasefrombones

Ca2levelBloodCa2level(about10mg/100mL)PTHincreasesthelevelofbloodItreleasesCa2+fromboneandstimulatesreabsorptionofCa2+inthekidneys从骨骼中释Italsohasanindirecteffect,stimulatingthekidneystoactivatevitaminD,whichpromotesintestinaluptakeofCa2+fromfood非直接作用：CalcitonindecreasesthelevelofbloodItstimulatesCa2+depositioninbonesandsecretionbykidneys降钙素增强钙在骨骼的沉积，AdrenalHormones肾上腺激素ResponsetoStressTheadrenalglandsareadjacenttotheEachadrenalglandactuallyconsistsoftwoglands:theadrenalmedulla(innerportion)肾上腺髓andadrenalcortex(outerportion肾上腺Theadrenalmedullasecretesepinephrine(adrenaline)andnorepinephrine(noradrenaline)Thesehormonesaremembersofaclassofcompoundscalledcatecholamines属于儿茶酚Theyaresecretedinresponsetostress-activatedimpulsesfromthenervoussystem属于机体对压Theymediatevariousfight-or-flightresponsesEpinephrineandTriggerthereleaseofglucoseandfattyacidsintotheblood葡萄糖和脂肪释放到血液Increaseoxygendeliverytobodycells增强氧气Directbloodtowardheart,brain,andskeletalmusclesandawayfromskindigestivesystem,andkidneys将血液供向心，脑，骨骼肌而减少皮ThereleaseofepinephrineandnorepinephrineoccursinresponsetoinvoluntarynervesignalsFigureandtheadrenalmedulla

andtheadrenalcortexSpinalcord

BloodvesselAdrenalmedullaandnorepinephrine.

Nerve

AdrenalcortexcorticoidsandEffectsofepinephrineandGlycogenbrokendowntoglucose;increasedbloodglucoseIncreasedbloodChangeinbloodflowpatterns,leadingtoexcretory,andreproductivesystemactivity

EffectsofRetentionofsodiumionsandwaterbyIncreasedbloodvolumeandblood

EffectsofProteinsandfatsdownandconvertedtoglucose,leadingtoPartialsuppressionofimmunesystemFigure(a)Short-termstressresponseandtheadrenal

Spinal(cross

Adrenalmedullasecretesepinephrineandnorepinephrine.

NerveEffectsofepinephrineandGlycogenbrokendowntoglucose;increasedbloodglucoseIncreasedbloodIncreasedbreathingIncreasedmetabolicChangeinbloodflowpatterns,leadingtoincreasedalertnessanddecreaseddigestive,excretory,andreproductivesystemactivity

SteroidHormonesfromtheAdrenalTheadrenalcortexreleasesafamilyofsteroidscalledcorticosteroidsinresponsetostress肾Thesehormonesaretriggeredbyahormonecascadepathwayviathehypothalamusandanteriorpituitary(ACTH被下丘脑前叶促肾上腺Humansproducetwotypesofcorticosteroids:glucocorticoids糖皮质激素andmineralocorticoids盐皮质激素Figure(b)Long-termstressresponseandtheadrenal

BloodvesselAdrenalcortexcorticoidsand

EffectsofRetentionofsodiumionsandwaterbyIncreasedblood