生物ch45hormones and the enrine systembody分泌到循環(huán)系統(tǒng)調(diào)節(jié)體內(nèi)信息的化學(xué)信號

Ch45HormonesandtheEndocrineOverview:TheBody’sLong-DistanceAnimalhormonesarechemicalsignalsthataresecretedintothecirculatorysystemandcommunicateregulatorymessageswithintheHormonesreachallpartsofthebody,butonlytargetcellshavereceptorsforthathormoneInsectmetamorphosis變形isregulatedbyTwosystemscoordinatecommunicationthroughoutthebody:theendocrinesystemandTheendocrinesystemsecreteshormonesthatcoordinateslowerbutlonger-actingresponsesincludingreproduction,development,energymetabolismgrowthandbehavior內(nèi)分泌較慢，調(diào)Thenervoussystemconveyshigh-speedelectricalsignalsalongspecializedcellscalledneuronsthesesignalsregulateothercells神經(jīng)系FigureFigureConcept45.1:Hormonesandothersignalingmoleculesbindtotargetreceptors,triggeringspecificresponsepathways Endocrinesignalingisjustoneofseveralwaysthatinformationistransmittedbetweenanimal IntercellularThewaysthatsignalaretransmittedbetweenanimalcellsareclassifiedbytwocriteria按兩個標(biāo)準(zhǔn)分類ThetypeofsecretingcellTheroutetakenbythesignalinreachingitstarget到達(dá)靶點的路徑EndocrineHormonessecretedintoextracellularfluidsbyendocrinecellsreachtheirtargetsviatheEndocrinesignalingmaintainshomeostasis體內(nèi)mediatesresponsestostimuli對刺激的反應(yīng)regulatesgrowthdevelopment發(fā)育TypesofSecretedSignalingSecretedchemicalsignalsPheromonesEndocrinesignals(hormonesaresecretedintoextracellularfluidsandtravelviathebloodstream激素分泌到胞外，由血液遞送全身Endocrineglands內(nèi)分泌腺areductlessandsecretehormonesdirectlyintosurroundingfluidHormonesmediateresponsestoenvironmentalstimuliandregulategrowth,development,andParacrineandAutocrineLocalregulatorsaremoleculesthatactovershortdistances,reachingtargetcellssolelyby(如TGF-b；Wnt；Notch;EGF…)Inparacrinesignaling,thetargetcellslienearInautocrinesignalingthetargetcellisalsothesecretingcell自分泌信號，調(diào)節(jié)分泌細(xì)胞自身Figure EndocrineParacrineAutocrineSynapticandNeuroendocrineInsynapticsignaling,neuronsformspecializedjunctionswithtargetcells,calledsynapsesAtsynapses,neuronssecretemoleculescalledneurotransmittersthatdiffuseshortdistancesandbindtoreceptorsontargetcells.Neurotransmittersyaroleinsensation,memory,cognition,and Inneuroendocrinesignaling,specializedneurosecretorycellssecretemoleculescalledneurohormonesthattraveltotargetcellsviatheFigure

Synaptic

Exocrineglandshaveductsandsecretesubstancesontobodysurfacesorintobodycavitiesforexampletearducts)外分泌腺體有SignalingbyMembersofthesameanimalspeciessometimescommunicatewithpheromones,chemicalsthatarereleasedintotheenvironmentandusedtocommunicatewithotherindividualsinthespecies Pheromonesservemanyfunctions,includingmarkingtrailsleadingtofood通往食物的蹤跡awiderangeoffunctionsthatincludedefiningterritories領(lǐng)地warningofpredators警戒,andattractingpotentialmates吸引配偶FigureEndocrineTissuesandInsometissues,endocrinecellsaregroupedtogetherinductlessorganscalledendocrineglands內(nèi)分泌細(xì)胞組成無管道的 Endocrineglandssecretehormonesdirectlyintosurroundingfluid直接分泌到胞外Thesecontrastwithexocrineglandswhichhaveductsandwhichsecretesubstancesontobodysurfacesorintocavities和外分泌腺不同F(xiàn)igure45.4 Majorendocrineglands:Hypothalamus下丘腦PinealglandPituitaryglandThyroidglandParathyroidglands(behindthyroid甲狀旁腺(atopkidneysOvaries(female)

endocrinecells:Heart心臟Liver肝臟Stomach胃KidneysChemicalClassesofThreemajorclassesofmoleculesfunctionashormonesinvertebratesPolypeptides(proteinsandAminesderivedfromaminoacids來源于氨基酸SteroidhormonesLipid-solublehormones(steroidhormonespasseasilythroughcellmembranes,whilewater-solublehormones(polypeptidesandaminesdonot脂溶性的激素可以輕易穿過細(xì)胞膜Thesolubilityofahormonecorrelateswiththelocationofreceptorsinsideoronthesurfaceoftargetcells可溶性的激素和細(xì)胞表面受體結(jié)合Figure

0.8Insulin胰島 Waterandlipidsolublehormonesdifferintheirpathsthroughabody體內(nèi)傳遞途徑不同Water-solublehormonesaresecretedbyexocytosis,travel lyinthebloodstreamandbindtocell-surfacereceptors水溶性的直接胞外Lipid-solublehormonesdiffuseacrosscellmembranes,travelinthebloodstreamboundtotransportproteins,anddiffusethroughthemembraneoftargetcells脂溶性的擴(kuò)散出細(xì)胞膜，HormoneReceptorLocation:ScientificInthe1960s,researchersstudiedtheaccumulationofradioactivesteroidhormonesinrattissueThesehormonesaccumulatedonlyintargetcellsthatwereresponsivetothehormonesTheseexperimentsledtothehypothesisthatreceptorsforthesteroidhormonesarelocatedinsidethetargetcellsFurtherstudieshaveconfirmedthatreceptorsforlipid-solublehormonessuchassteroidsarelocatedinsidecellsResearchershypothesizedthatreceptorsforwater-solublehormoneswouldbelocatedonthecellsurfaceTheyinjectedawater-solublehormoneintothetissuesofThehormonetriggeredaresponseonlywhenitwasallowedtobindtocellsurfacereceptorsThisconfirmedthatwater-solublereceptorswereonthecellsurface

Signal

Signal

PathwayforWater-SolubleBindingofahormonetoitsreceptorinitiatesasignaltransductionpathwayleadingtoresponsesinthecyto sm,enzymeactivation,orachangeingeneexpression激素和受體結(jié)合Signalingbyanyofthesehormonesinvolvesthreekeyevents:信號轉(zhuǎn)導(dǎo)步驟ReceptionSignaltransductionResponseAnimation:Water-SolubleRight-clickslide/ Thehormoneepinephrinehasmultipleeffectsinmediatingthebody’sresponsetoshort-termstress腎上腺素對短期壓力有多種反應(yīng)Epinephrinebindstoreceptorsonthe membraneoflivercells和肝的受體結(jié)合Thistriggersthereleaseofmessengermoleculesthatactivateenzymesandresultinthereleaseofglucoseintothebloodstream刺激G

Gprotein-coupled

G

Gprotein-coupled

InhibitionofPromotionof

PathwayforLipid-SolubleTheresponsetoalipid-solublehormoneisusuallyachangeingeneexpression脂溶通常直接導(dǎo)致Steroids,thyroidhormones,andthehormonalformofvitaminDentertargetcellsandbindtoproteinreceptorsinthecyto smornucleus固醇，甲狀腺激素等進(jìn)入靶細(xì)Protein-receptorcomplexesthenactastranscriptionfactorsinthenucleus,regulatingtranscriptionofspecificgenes蛋白和受體復(fù)合體進(jìn)入細(xì)胞核，作為轉(zhuǎn)錄因子調(diào)節(jié)特Animation:Lipid-SolubleRight-clickslide/

for

MultipleEffectsofThesamehormonemayhavedifferenteffectsontargetcellsthathave同一激素在不同靶細(xì)胞作用DifferentreceptorsforthehormoneDifferentsignaltransductionpathwaysFigure

Samereceptorsbutdifferentintracellularproteins(notshown)

andglucoseisreleasedfromcell.

(a)Livercell (b)Skeletalmusclebloodvessel

(c)IntestinalbloodSignalingbyLocalLocalregulatorsaresecretedmoleculesthatlinkneighbouringcellsordirectlyregulatethesecretingcell局部調(diào)節(jié)素調(diào)節(jié)附近細(xì)胞或者分泌TypesoflocalCytokines細(xì)胞因子andgrowthfactors生長因Nitricoxide(NO) Growthfactors生長因子proteinspolypeptidesthatstimulatecellExample:nervegrowthfactor(NGF)affectscertainembryoniccells,develo bloodcells,andotherkindsofcellsNitricoxideThoughagas,NOisanimportantlocalWhensecretedbyneurons,itactsasaWhensecretedbywhitebloodcells,itkillsbacteriaandcancercells由白細(xì)胞分泌則可以Andwhensecretedbyendothelialcells,itdilatesthewallsofbloodvessels由血管內(nèi)皮Viagra modifiedfattyacidsPGssecretedbythe centastimulateuterinecontractionsduringchildbirth.胎盤分泌 OtherPGs yaroleininfl tion炎癥反Intheimmunesystem,prostaglandinspromotefeverand tionandintensifythesensationofProstaglandinshelpregulateaggregationofets,anearlystepinformationofbloodclotsRoleinbloodflowtothelungs控制血流進(jìn)入ProstaglandinE、prostaglandinCoordinationofNeuroendocrineandEndocrineSignalingTheendocrineandnervoussystemsgenerallyactcoordina ytocontrolreproductionandForexampleinlarvaeofbutterfliesandmoths,thesignalsthatdirectmoltingoriginateinthebrain蝴蝶和蛾子幼蟲蛻皮信號來源于腦部Ininsects,moltinganddevelopmentarecontrolledbyacombinationofhormonesAbrainhormone(PTTH前胸腺促泌素)stimulatesreleaseofecdysteroid蛻皮激素fromtheprothoracicglands前胸腺retentionoflarvalcharacteristicsEcdysone蛻promotesmoltinginthepresenceofjuvenilehormone)anddevelopment(intheabsenceofjuvenilehormone)ofadultcharacteristics

Corporaallata咽側(cè)體

Concept45.2:Feedbackregulationandantagonistichormonepairsarecommoninendocrinesystems反饋調(diào)控和拮抗激素HormonesareassembledintoregulatorySimpleHormoneHormonesarereleasedfromanendocrinecell,travelthroughthebloodstream,andin ctwithspecificreceptorswithinatargetcelltocauseaphysiologicalresponse激素由內(nèi)分泌細(xì)胞分泌，F(xiàn)orexamplethereleaseofacidiccontentsofthestomachintotheduodenumstimulatesendocrinecellstheretosecretesecretin腸促胰液素胃的酸Thiscausestargetcellsinthepancreasaglandbehindthestomach,toraisethepHintheduodenum導(dǎo)致胰腺中靶細(xì)胞升高十二指腸的pHFigure

LowpH

Scellsofduodenumsecretethehormonesecretin().

BicarbonateInasimpleneuroendocrinepathway,thestimulusisreceivedbyasensoryneuronwhichstimulatesaneurosecretorycell簡單的神經(jīng)內(nèi)分泌通路:感覺Theneurosecretorycellsecretesaneurohormone,whichentersthebloodstreamandtravelstotargetcells神經(jīng)分泌細(xì)胞分泌神經(jīng)Figure

PositivePositiveBlood

Posteriorpituitarysecretestheoxytocin( SmoothmuscleinMilkAnegativefeedback負(fù)反loopinhibitsaresponsebyreducingtheinitialstimulusthuspreventingexcessivepathwayactivityPositivefeedback正反饋rein sastimulustoproduceanevengreaterresponseForexample,inm lsoxytocincausesthereleaseofmilk,causinggreatersucklingbyoffspringwhichstimulatesthereleaseofmoreoxytocin催產(chǎn)素InsulinandGlucagon:ControlofBloodInsulin胰島素(decreasesbloodglucose)andglucagon(increasesbloodglucose)areantagonistichormonesthathelpmaintainglucosehomeostasisThepancreashasclustersofendocrinecellscalledpancreaticisletswithalphacellsthatproduceglucagonandbetacellsthatproduceFigureBodycellstakeupmore

Betacellsofintothelevel

Livertakesupglucoseandstoresitas

Bloodglucoselevelrises(forinstance,aftereatingacarbohydrate-richmeal).Bloodglucoselevellevelrises.

Bloodglucoselevel ameal).Liverbreaksandreleasesglucoseintotheblood.

Alphacellsofpancreasreleaseglucagonintotheblood.TargetTissuesforInsulinandInsulinreducesbloodglucoselevelsPromotingthecellularuptakeofglucose提 Slowingglycogenbreakdownintheliver減Promotingfatstoragenotbreakdown增強(qiáng)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垂體后葉andanteriorpituitary垂體前葉Theposteriorpituitary垂體后葉storesandsecreteshormonesthataremadeinthe Theanteriorpituitarymakesandreleaseshormonesunderregulationofthehypothalamus在下丘腦控制下分泌激素Adenohypophysis腺垂體Figure

glandSpinalcord

Thalamus丘腦Hypothalamus下丘腦gland垂體

ThetwohormonesreleasedfromtheposteriorpituitaryactdirectlyonnonendocrinetissuesOxytocin催產(chǎn)素inducesuterinecontractionsandregulatesmilksecretionbythem ryglandsSucklingsendsamessagetothehypothalamusviathenervoussystemtoreleaseoxytocin,whichfurtherstimulatesthemilkglandsThisisanexampleofpositivefeedback,wherethestimulusleadstoanevengreaterresponsewaterreabsorptioninthekidneysregulatesphysiologyandbehaviorFigure

cellsofthe

uterinemusclesAnteriorPituitaryHormoneproductionintheanteriorpituitaryiscontrolledbyreleasingandinhibitinghormonesfromthehypothalamus前葉激素被下丘腦的分泌或者抑制激素調(diào)節(jié)Forexample,prolactin-releasinghormone催乳素釋放激素fromthehypothalamusstimulatestheanteriorpituitarytosecreteprolactin(PRL)催乳素,whichhasaroleinmilkproductionForexampletheproductionofthyrotropinreleasinghormone促甲狀腺激素釋放激素(TRH)inthehypothalamusstimulatessecretionofthethyroidstimulatinghormone甲狀腺刺激素(TSH)fromtheanteriorpituitaryFigureFSH促 NontropiceffectsNontropicandtropicGH生長激素 releasingand

cellsofthePortaloftheanterior FSHand

otherTableTableThyroidRegulation:AHormoneCascadeAhormonecanstimulatethereleaseofaseriesofotherhormones,thelastofwhichactivatesanonendocrinetargetcellthisiscalledahormonecascadepathway激素路Thereleaseofthyroidhormoneresultsfromahormonecascadepathwayinvolvingthehypothalamus,anteriorpituitary,andthyroidgland甲狀腺激素分泌受包括下丘腦， Hormonecascadepathwaystypicallyinvolvenegativefeedback激素級 Figure

SensoryNeurosecretorycellBloodEndocrinecell

hormone Anteriorpituitarysecreteshormone(TSH,alsoknownasthyrotropinThyroidglandsecretesthyroidhormone(T3andT4).BodyFigure

SensoryneuronNeurosecretoryReleasingBloodAnterior

hormone(TRH Anteriorpituitarysecreteshormone(TSH,alsoknownasthyrotropin).Figure

NegativeNegativeEndocrine

hormone(TSH,alsoknownasthyrotropin).Thyroidglandsecretesthyroidhormone(T3andT4BodytissuesDisordersofThyroidFunctionandHypothyroidism甲狀腺功能減退,toolittlethyroidfunctioncanproducesymptomssuchWeightgain,lethargy,coldproductionofthyroidhormone,canleadtoHightemperature,sweating,weightloss,irritabilityandhighbloodpressureMalnutritioncanalterthyroidfunction Gravesdisease毒性彌漫性甲狀腺腫aformofhyperthyroidismcausedbyautoimmunity,istypifiedbyprotrudingeyes自身免疫導(dǎo)致的一種ThyroidhormonereferstoapairofTriiodothyronin(T3),withthreeiodineThyroxine(T4)withfouriodineInsufficientdietaryiodineleadstoanenlargedthyroidglandcalledagoiter碘攝取不足可能導(dǎo)FigureLowleveliodine

HighleveliodineEvolutionofHormoneOverthecourseofevolutionthefunctionofagivenhormonemaydivergebetweenspeciesForexample,thyroidhormoneysaroleinmetabolismacrossmanylineages,butinhastakenonauniquefunctionstimulatingtheresorptionofthetadpoletailduringmetamorphosis青蛙的甲狀腺素促進(jìn)變形Prolactin催乳激素alsohasabroadrangeofactivitiesinvertebratesFigureAdultregulatesskincolorinamphibians,fish,andreptilesbycontrollingpigmentdistributioninmelanocytes調(diào)節(jié)黑色素分布調(diào)節(jié)體色I(xiàn)nm ls,MSH ysadditionalrolesinhungerandmetabolisminadditiontoTropicandNontropicAtropichormoneregulatesthefunctionofendocrinecellsorglands促激素調(diào)節(jié)內(nèi)分泌細(xì)ThreeprimarilytropichormonesFollicle-stimulatinghormone(FSH)促 Luteinizinghormone(LH) Growthhormone(GH)issecretedbytheanteriorpituitaryglandandhastropicandItpromotesgrowthdirectlyandhasdiverseItstimulatesproductionofgrowthfactorsAnexcessofGHcancausegigantism巨人癥,whilealackofGHcancausedwarfism侏儒癥Concept45.4:Endocrineglandsrespondtodiversestimuliinregulatinghomeostasis,development,andbehaviorEndocrinesignalingregulateshomeostasis,development,andbehavior內(nèi)分泌信號調(diào)節(jié)體ParathyroidHormoneandVitaminD:ControlofBloodCalciumTwoantagonistichormonesregulatethehomeostasisofcalcium(Ca2+inthebloodof ls兩種拮抗激素調(diào)節(jié)體內(nèi)鈣離子平衡Parathyroidhormone(PTH)甲狀旁腺素isreleasedbytheparathyroidglands甲狀旁腺分Calcitonin降鈣isreleasedbythethyroidgland甲狀腺分泌的降鈣素uptakein

vitamin Stimulatesuptakeinlevel

Ca2releasefrombones

Ca2levelBloodCa2level(about10mg/100mL)PTHincreasesthelevelofbloodItreleasesCa2+fromboneandstimulatesreabsorptionofCa2+inthekidneys從骨骼中釋Italsohasanindirecteffect,stimulatingthekidneystoactivatevitaminD,whichpromotesintestinaluptakeofCa2+fromfood非直接作用：CalcitonindecreasesthelevelofbloodItstimulatesCa2+depositioninbonesandsecretionbykidneys降鈣素增強(qiáng)鈣在骨骼的沉積，AdrenalHormones腎上腺激素ResponsetoStressTheadrenalglandsareadjacenttotheEachadrenalglandactuallyconsistsoftwoglands:theadrenalmedulla(innerportion)腎上腺髓andadrenalcortex(outerportion腎上腺Theadrenalmedullasecretesepinephrine(adrenaline)andnorepinephrine(noradrenaline)Thesehormonesaremembersofaclassofcompoundscalledcatecholamines屬于兒茶酚Theyaresecretedinresponsetostress-activatedimpulsesfromthenervoussystem屬于機(jī)體對壓Theymediatevariousfight-or-flightresponsesEpinephrineandTriggerthereleaseofglucoseandfattyacidsintotheblood葡萄糖和脂肪釋放到血液Increaseoxygendeliverytobodycells增強(qiáng)氧氣Directbloodtowardheart,brain,andskeletalmusclesandawayfromskindigestivesystem,andkidneys將血液供向心，腦，骨骼肌而減少皮ThereleaseofepinephrineandnorepinephrineoccursinresponsetoinvoluntarynervesignalsFigureandtheadrenalmedulla

andtheadrenalcortexSpinalcord

BloodvesselAdrenalmedullaandnorepinephrine.

Nerve

AdrenalcortexcorticoidsandEffectsofepinephrineandGlycogenbrokendowntoglucose;increasedbloodglucoseIncreasedbloodChangeinbloodflowpatterns,leadingtoexcretory,andreproductivesystemactivity

EffectsofRetentionofsodiumionsandwaterbyIncreasedbloodvolumeandblood

EffectsofProteinsandfatsdownandconvertedtoglucose,leadingtoPartialsuppressionofimmunesystemFigure(a)Short-termstressresponseandtheadrenal

Spinal(cross

Adrenalmedullasecretesepinephrineandnorepinephrine.

NerveEffectsofepinephrineandGlycogenbrokendowntoglucose;increasedbloodglucoseIncreasedbloodIncreasedbreathingIncreasedmetabolicChangeinbloodflowpatterns,leadingtoincreasedalertnessanddecreaseddigestive,excretory,andreproductivesystemactivity

SteroidHormonesfromtheAdrenalTheadrenalcortexreleasesafamilyofsteroidscalledcorticosteroidsinresponsetostress腎Thesehormonesaretriggeredbyahormonecascadepathwayviathehypothalamusandanteriorpituitary(ACTH被下丘腦前葉促腎上腺Humansproducetwotypesofcorticosteroids:glucocorticoids糖皮質(zhì)激素andmineralocorticoids鹽皮質(zhì)激素Figure(b)Long-termstressresponseandtheadrenal

BloodvesselAdrenalcortexcorticoidsand

EffectsofRetentionofsodiumionsandwaterbyIncreasedblood