BILD 2: Multicellular LifeLECTURE #17Website: http://www.biology.ucsd.edu/classes/bild2.WI11.1Instructor: Darwin K. Berg ([email protected])ANNOUNCEMENTS:1) Second midterm: Wed, Feb 16. Material: up through today’slecture (Lec #17.2) Exam room: Here, WLH 2001.3) Review Session: Tues, Feb 15, 6-9 pm in Pacific Hall 3500. Building Access Code for the review: 701181(Note: Exam room & time for those with special accommodations:3502 Pacific Hall, 10-11:30 am Wed, Feb, 16)Posteriorvena cavaRenal arteryand veinUrinarybladderUreterAortaUrethra(a) Excretory organs and major associated blood vessels(b) Kidney structureSection of kidneyfrom a rat4 mmKidneyUreterRenalmedullaRenalcortexRenalpelvisFig. 44-14a,b: The Mammalian Excretory SystemCorticalnephronJuxtamedullarynephronCollectingduct(c) Nephron typesTorenalpelvisRenalmedullaRenalcortex10 mAfferent arteriolefrom renal arteryEfferentarteriole fromglomerulusSEMBranch ofrenal veinDescendinglimbAscendinglimbLoop ofHenle(d) Filtrate and blood flowVasarectaCollectingductDistaltubulePeritubular capillariesProximal tubuleBowman’s capsuleGlomerulusFig. 44-14c,d: The Mammalian Excretory SystemKeyActivetransportPassivetransportINNERMEDULLAOUTERMEDULLAH2OCORTEXFiltrateLoop ofHenleH2OK+HCO3–H+NH3Proximal tubuleNaCl NutrientsDistal tubuleK+H+HCO3–H2OH2ONaClNaClNaClNaClUreaCollectingductNaClFig. 44-15: The Nephron and Collecting Duct: Regional Functions of theTransport EpitheliumFiltrate:H2OSalts (NaCl & others)HCO3-H+Ureaglucose, amino acids,some drugsFig. 44-16: How the human kidney concentrates urine: the two-solute modelKeyActivetransportPassivetransportINNERMEDULLAOUTERMEDULLACORTEXH2O300300300H2OH2OH2O400600900H2OH2O1,200H2O300Osmolarity ofinterstitialfluid(mOsm/L)4006009001,200100NaCl100NaClNaClNaClNaClNaClNaCl2004007001,200300400600H2OH2OH2OH2OH2OH2OH2ONaClNaClUreaUreaUreaFig. 44-19: Regulation of Fluid Retention by Anti-Diuretic HormoneThirstDrinking reducesblood osmolarityto set point.Osmoreceptors inhypothalamus triggerrelease of ADH.IncreasedpermeabilityPituitaryglandADHHypothalamusDistaltubuleH2O reab-sorption helpsprevent furtherosmolarityincrease.STIMULUS:Increase in bloodosmolarityCollecting ductHomeostasis:Blood osmolarity(300 mOsm/L)(a)Exocytosis(b)AquaporinwaterchannelsH2OH2OStoragevesicleSecond messengersignaling moleculecAMPINTERSTITIALFLUIDADHreceptorADHCOLLECTINGDUCTLUMENCOLLECTINGDUCT CELLFig. 44-21: Regulationof Blood Volume andPressure by the Renin-Angiotensin-Aldosteronesystem (RAAS)ReninDistaltubuleJuxtaglomerularapparatus (JGA)STIMULUS:Low blood volumeor blood pressureHomeostasis:Blood pressure,volumeLiverAngiotensinogenAngiotensin IACEAngiotensin IIAdrenal glandAldosteroneArterioleconstrictionIncreased Na+and H2O reab-sorption indistal
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