LE 43-8Antigen-bindingsiteDisulfidebridgeLightchainVVCCCCVVAntigen-binding siteVariable regionsConstant regionsTransmembraneregionAntigen-binding siteCVCVPlasmamembraneT cellβ chainα chainDisulfide bridgeCytoplasm of T cellA T cell receptor consists of one αchain and one β chain linked by adisulfide bridge.A B cell receptor consists of two identical heavychains and two identical light chains linked byseveral disulfide bridges.Heavy chainsCytoplasm of B cellB cellLE 43-9Antigen-presentingcellAntigenfragmentClass II MHCmoleculeT cellreceptorHelper T cellAntigenfragmentClass I MHCmoleculeT cellreceptorCytotoxic T cellInfected cellMicrobeLE 43-17MacrophageClass II MHCmoleculeBacteriumPeptideantigenCD4TCRHelper T cellActivatedhelper T cellCytokinesClone of memoryB cellsEndoplasmicreticulum ofplasma cellClone of plasma cellsSecreted antibodymoleculesB cell+LE 43-14_3First exposure to antigenAntigens engulfed anddisplayed by dendritic cellsActivateHumoral immune responseCell-mediated immune responseHelperT cellActive andmemoryhelperT cellsGives rise toAntigens displayedby infected cellsActivateCytotoxicT cellMemorycytotoxicT cellsGives rise toSecretedcytokinesactivateActivecytotoxicT cellsDefend against infected cells, cancercells, and transplanted tissuesActivateGives rise toSecrete antibodies that defend againstpathogens and toxins in extracellular fluidPlasmacellsMemoryB cellsB cellsIntact antigensLE 44-8Nitrogenous basesNucleic acidsAmino acidsProteins—NH2Amino groupsMost aquaticanimals,including mostbony fishesMammals, mostamphibians,sharks, some bonyfishesMany reptiles(includingbirds), insects,land snailsAmmonia Urea Uric acidLE 44-13Excretory organs and major associated blood vesselsRenalmedullaRenalcortexRenalpelvisSection of kidney from a ratKidney structureUreterKidneyGlomerulusBowman’s capsuleProximal tubulePeritubular capillariesAfferentarteriolefrom renalarteryEfferentarteriole from glomerulusDistaltubuleCollectingductSEM20 µmBranch ofrenal veinFiltrate and blood flowVasarectaDescendinglimbAscendinglimbLoopofHenleRenalmedullaNephronTorenalpelvisRenalcortexCollectingductJuxta-medullarynephronCorticalnephronPosterior vena cavaRenal artery and veinAortaUreterUrinary bladderUrethraLE 44-14FiltrateH2OSalts (NaCl and others)HCO3–H+UreaGlucose; amino acidsSome drugsKeyActive transportPassive transportINNERMEDULLAOUTERMEDULLANaClH2OCORTEXDescending limbof loop ofHenleProximal tubuleNaClNutrientsHCO3–H+K+NH3H2ODistal tubuleNaClHCO3–H+K+H2OThick segmentof ascendinglimbNaClNaClThin segmentof ascendinglimbCollectingductUreaH2OLE 44-15_3INNERMEDULLAOUTERMEDULLACORTEXOsmolarity ofinterstitialfluid(mosm/L)NaClUreaH2OActivetransportPassivetransport300300300100100400200H2OH2OH2OH2OH2OH2O6004009007001200300400H2O60012001200600900300400NaClNaClNaClNaClNaClNaClUreaH2OUreaH2OH2OH2OH2OH2OLE 45-3SECRETORYCELLHormonemoleculeSignal receptorVIABLOODVIABLOODTARGETCELLTARGETCELLSignaltransductionpathwayORCytoplasmicresponseDNANUCLEUSNuclearresponseReceptor in plasma membrane Receptor in cell nucleusDNANUCLEUSmRNASynthesis ofspecific proteinsSignaltransductionand responseSignalreceptorHormonemoleculeSECRETORYCELLLE 45-4Different receptorsdifferent cell responsesEpinephrineα receptorEpinephrineβ receptorEpinephrineβ receptorVesselconstrictsVesseldilatesIntestinal bloodvesselSkeletal muscleblood vesselLiver cellDifferent intracellular proteins different cell responsesGlycogendepositsGlycogenbreaks downand glucoseis releasedfrom cellLE 45-12Beta cells ofpancreasrelease insulininto the blood.InsulinLiver takesup glucoseand stores itas glycogen.STIMULUS:Rising blood glucoselevel (for instance, aftereating a carbohydrate-rich meal)Blood glucose leveldeclines to set point;stimulus for insulinrelease diminishes.Homeostasis:Blood glucose level(about 90 mg/100 mL)STIMULUS:Dropping blood glucoselevel (for instance, afterskipping a meal)Blood glucose levelrises to set point;stimulus for glucagonrelease diminishes.Liver breaksdown glycogenand releasesglucose into theblood.Body cellstake up moreglucose.Alpha cells of pancreasrelease glucagon into the blood.GlucagonLE 44-16aOsmoreceptorsin hypothalamusHypothalamusADHPituitaryglandIncreasedpermeabilityDistaltubuleThirstDrinking reducesblood osmolarityto set pointCollecting ductH2O reab-sorption helpsprevent furtherosmolarityincreaseHomeostasis:Blood osmolaritySTIMULUSThe release of ADH istriggered when osmo-receptor cells in thehypothalamus detect anincrease in the osmolarityof the bloodLE 45-11STIMULUS:Rising bloodCa2+ levelThyroid glandreleasescalcitonin.CalcitoninStimulatesCa2+ depositionin bonesReducesCa2+ uptakein kidneysBlood Ca2+level declinesto set pointHomoeostasis:Blood Ca2+ level(about 10 mg/100 mL)STIMULUS:Falling bloodCa2+ levelBlood Ca2+level risesto set pointStimulatesCa2+ releasefrom bonesPTHParathyroidglandStimulates Ca2+ uptake in kidneysActivevitamin DIncreasesCa2+ uptakein intestinesLE 46-11Primary germ cellin embryoMitoticdivisionPrimaryoocyteOvaryOogoniumDifferentiationOogoniumin ovaryPrimaryoocytewithinfollicleGrowingfollicleSecondaryoocyteCompletion of meiosis Iand onset of meiosis IIOvulationFirst polar bodyMature follicleEntry of spermtriggerscompletionof meiosis IISecond polar bodyOvumRupturedfollicleOvulatedsecondary oocyteCorpus luteumDegen-erating corpus luteumLE 46-12SpermatogoniumPrimary spermatocyte(in prophase of meiosis I)Mitotic division, producinglarge numbers of spermatogoniaMeiosis I completedDifferentiation and onset of meiosis ISecondary spermatocyteMeiosis IIEarlyspermatidsSpermatids(at two stages ofdifferentiation)DifferentiationSperm cellsNeckHeadMidpieceTailPlasma membraneMitochondriaAcrosome NucleusSertoli cellnucleusLumen ofSeminiferous tubuleCross sectionof seminiferoustubuleTestisEpididymisSeminiferous tubuleLE 46-13HypothalamusAnterior pituitaryControl by hypothalamusPituitary gonadotropinsin bloodFSH LHFSHLHGnRHInhibited by combination ofestrogen and progesteroneInhibited by low levels ofestrogenStimulated by high levels of estrogenLH surge triggersovulationFSH and LH stimulatefollicle to growMaturefollicleGrowing follicleOvarian cycleCorpusluteumDegeneratingcorpus luteumFollicular phaseOvulation Luteal phaseProgesterone andestrogen secretedby corpus luteumEstrogen secretedby growing follicle inincreasing amountsProgesterone and estro-gen promote thickeningof endometriumPeak causesLH surgeOvarian hormonesin bloodEstrogen levelvery lowProgesteroneEstrogenEndometriumUterine (menstrual) cycleMenstrual
View Full Document
Unlocking...