The Urinary SystemIntro to the Urinary SystemKidneysStructure of KidneyBlood Supply to KidneysStructure of NephronsNephrons and Collecting DuctsUrine FormationGlomerular FiltrationTubular ReabsorptionTubular SecretionCharacteristics of UrineUrineAbnormal Urinary ConstituentsUretersKidney StonesUrinary BladderSlide 18UrethraMicturition - VoidingRegulation of H2O intake and outputReabsorption of Water and ElectrolytesUrinary DiseasesPolycystic KidneysThe EndThe Urinary SystemThe Urinary SystemChapter 15Chapter 15Intro to the Urinary SystemIntro to the Urinary SystemHomeostatic organs – purity, consistency Homeostatic organs – purity, consistency of internal fluidsof internal fluidsFilter gallons of fluids from bloodstream – Filter gallons of fluids from bloodstream – remove waste return nutrientsremove waste return nutrientsRegulate blood volume, chemical makeup Regulate blood volume, chemical makeup and balanceand balancePart of Urinary SystemPart of Urinary SystemKidneysKidneysWhere located? Where located? Receive some protection Receive some protection from ribsfrom ribsRt slightly lower, crowded Rt slightly lower, crowded by liverby liverRenal Hilum – ureters, Renal Hilum – ureters, renal blood vessels, nervesrenal blood vessels, nervesFibrous Capsule – Fibrous Capsule – encloses kidney, glistenencloses kidney, glistenPerirenal Fat Capsule – Perirenal Fat Capsule – surrounds, protectssurrounds, protectsRenal Fascia Capsule – Renal Fascia Capsule – anchors to muscleanchors to muscleFigure 15.1aStructure of KidneyStructure of Kidney3 Regions3 RegionsRenal Cortex – outer Renal Cortex – outer layerlayerRenal Medulla – Renal Medulla – middlemiddleRenal pyramids – apex Renal pyramids – apex and baseand baseStripped appearanceStripped appearanceRenal columns – sep. Renal columns – sep. pyramidspyramidsRenal PelvisRenal PelvisContinuous with ureterContinuous with ureterCalyces – enclose tip of Calyces – enclose tip of pyramid, collect urinepyramid, collect urineFigure 15.2a–bBlood Supply to KidneysBlood Supply to KidneysCleanse blood and adjust componentsCleanse blood and adjust componentsVascular or not?Vascular or not?¼ of total blood supply through kidneys ¼ of total blood supply through kidneys every minuteevery minuteStructure of NephronsStructure of Nephrons1+ mill in each kidney1+ mill in each kidneyFunctional unit of kidney, form Functional unit of kidney, form urineurine2 Main Structures2 Main StructuresGlomerulus – knot of capillariesGlomerulus – knot of capillariesRenal Tube – glomerular or Renal Tube – glomerular or Bowman’s CapsuleBowman’s CapsuleProximal Convoluted Tubule (PCT)Proximal Convoluted Tubule (PCT)Very Dense MicrovilliVery Dense MicrovilliLoop of HenleLoop of HenleDistal Convoluted Tubule (DCT)Distal Convoluted Tubule (DCT)Collecting DuctCollecting DuctFigure 15.3aNephrons and Collecting DuctsNephrons and Collecting Ducts2 Types of nephrons2 Types of nephronsCortical Nephrons – Cortical Nephrons – located in cortexlocated in cortexJuxtamedullary nephrons Juxtamedullary nephrons – cortex-medullary – cortex-medullary junctionjunctionCollecting Ducts – Collecting Ducts – receive urine from many receive urine from many nephrons, down through nephrons, down through medullary pyramid, medullary pyramid, deliver to calycesdeliver to calycesFigure 15.3bUrine FormationUrine Formation3 Processes3 ProcessesGlomerular FiltrationGlomerular FiltrationTubular ReabsorptionTubular ReabsorptionTubular SecretionTubular SecretionFigure 15.4Glomerular FiltrationGlomerular FiltrationNonselective, passive Nonselective, passive processprocessFluid from blood passes into Fluid from blood passes into glomerular capsule of renal glomerular capsule of renal tubuletubuleCalled filtrate – blood Called filtrate – blood plasma w/o blood proteinsplasma w/o blood proteinsBlood cells and proteins too Blood cells and proteins too large, when found in urine large, when found in urine indication problem with indication problem with glomerular filtrationglomerular filtrationIf blood pressure normal, If blood pressure normal, filtrate made, in blood filtrate made, in blood pressure drops, no pressure drops, no movement out of bloodmovement out of bloodFigure 15.5Tubular ReabsorptionTubular ReabsorptionIn addition to waste, nutrients In addition to waste, nutrients also in filtratealso in filtrateHH22O, glucose, a.a., ionsO, glucose, a.a., ionsReclaim from filtrateReclaim from filtratePCT – tubule cells are PCT – tubule cells are “transporters”, take up from “transporters”, take up from filtrate and pass out into filtrate and pass out into extracellular space -> extracellular space -> peritubular capillary bloodperitubular capillary bloodSome passive, some use Some passive, some use carriers, are no carriers for carriers, are no carriers for substances body doesn’t needsubstances body doesn’t needNitrogenous Waste Products – Nitrogenous Waste Products – high concentrations in urine – high concentrations in urine – urea, uric acid, creatinineurea, uric acid, creatinineIons absorbed or not depends Ions absorbed or not depends on bloodon bloodFigure 15.5Tubular SecretionTubular SecretionH+ and K+ ionsH+ and K+ ionsCreatinineCreatinineMovement from blood Movement from blood to filtrateto filtrateAdditional means for Additional means for controlling blood pHcontrolling blood pHCharacteristics of UrineCharacteristics of UrineFiltrate vs. Urine – Are they different?Filtrate vs. Urine – Are they different?150-180 L of filtrate in 24hrs, only 1.0-1.8 L of 150-180 L of filtrate in 24hrs, only 1.0-1.8 L of urineurineFiltrate – Everything that blood plasma, Filtrate – Everything that blood plasma, except blood proteinsexcept blood proteinsUrine – Urine – by time filtrate reaches collecting ducts, lost by time filtrate reaches collecting ducts, lost most of H2O, and nutrients. Mostly most of H2O, and nutrients. Mostly nitrogenous wastes and unneeded substancesnitrogenous wastes and unneeded substancesUrineUrineYellow color – urochrome, pigment form destroyed Hb, Yellow color – urochrome, pigment form destroyed Hb, pale vs. darker, dietpale vs. darker, dietSterile when formedSterile when formedpH is slightly acidic pH=6.0pH is slightly acidic pH=6.0Diet can change, protein, wheat, or vegetarianDiet can change, protein, wheat, or