组织学与胚胎学14 泌尿系统(中英)

UrinarySystemKidney肾Ureter输尿管Urinarybladder膀胱Kidney肾A.Introduction:1.Generalstructure:

Eachkidneyhasaconcaveborder,thehilum,wherebloodvesselsandureterexitandcommunicatethekidney.Therenalpelvis,theexpandedupperendoftheureter,branchesandrebranchesintomajorcalycesandminorcalyces.2.Capsule被膜:

CTcontainingrichfatcells.

3.Cortex:皮质Mainlylocatesatperipherywiththerenalcolumn肾柱,thepillar-shapedcortexthatexistsbetweenpyramid-likemedulla.4.Medulla髓质:Centrallylocated10~18pyramid-likestructuresknownasrenalpyramids

（肾椎体）,whosebasesradiallysendoutthe

medullaryrays髓放线thatseparatethecortexintocorticallabyrinth

（皮质迷路）.肾叶：

每个肾锥体及与其相连的皮质肾小叶：

每个髓放线及其周围的皮质迷路5.Kidneycontainsnumerousuriniferoustubules泌尿小管,whicharecomposedofnephrons肾单位andcollectingtubules集合管.6.Nephron肾单位:Thestructuralandfunctionalunitofkidney.renalcorpuscle肾小体:renalglomerulus+glomeruluscapsuleb.renaltubule肾小管:

proximalconvolutedtubules(C)+Henle’sloop+distalconvolutedtubules(C).7.Functionsofkidney:

Clearanceofmetabolismwastesinbloodstream;

RegulationofminerallevelandpHvalueinbody.Nephron（肾单位）Renalcorpuscle（肾小体）Renaltubule（肾小管）Proximaltubule～convolutedtubule～straighttubuleThinsegmentDistaltubule～straighttubule～convolutedtubuleMedullaryloop肾单位nephron肾小体（Renalcorpuscle

）

血管球肾小囊肾小管（Renaltubule

）近端小管～曲部～直部细段远端小管～直部～曲部髓袢Corticalnephron（皮质~）85%，shortloopformationofurineJuxtamedullarynephron（髓旁~）15%，longloopConcentrateurine1.

Renalcorpuscle

（肾小体）

:

Theplacewherethebloodisfilteredtoformpre-urine.Hasvascularpole血管极,wheretheafferentarteriole入球微Aentersandthinnerefferentarteriole出球微Aleavesrenalcorpuscle,andurinarypole尿极,wheretheproximalconvolutedtubuleleavesthecorpuscle.renalglomerulus(血管球):

anastomizingfenestratedCaps

有孔毛细血管withoutdiaphragm.permeability↑,havecontinuousbasementmembrane

？Mesangium(血管系膜，球内系膜）

Intraglomerularmesangialcell球内系膜细胞LM：smallanddarknucleus，undistinguishedfromothercellsEM：Processes：mayprotrudebetweenendotheliumandbasementmembrane。abundantorganelles：rER、Golgi、lysosome、phagocytoticvesicles、microtubule、microfilamentmesangialmatrix系膜基质Function：1、synthesizebasementmembraneandmesangialmatrix合成基膜和基质2、phagocytosis吞噬基膜上的沉淀物，维持通透性3、participateinrenovationofthebasementmembrane参与基膜更新4、cellcontraction→controlbloodstreamofglomus控制血管球血流量。b.glomeruluscapsule肾小囊(Bowman'scapsule):parietallayer壁层:

linedbysimplesquamousepithelium.capsularspace肾小囊腔thespacesbetweenthe2layers.viscerallayer脏层:composedof

podocytes(足细胞）包绕在血管球毛细血管外面LM：undistinguishedwithothercellsEM：body→severalprimaryprocesses初级突起→

numeroussecondaryprocesses次级突起;Filtrationslits(裂孔）:spacesbetweensecondaryprocesses,25nm。Slitmembrane(裂孔膜):4～6nmPodocyte

Glomerularbasementmembrane血管球基膜thickerthangeneralbasementmembrane，about330nm。3layers，middlelayerthickandcompact，othersthinandloose。IVcollagen、laminin

（层粘连蛋白）、proteoglycan阻止血浆带负电荷的物质通过，防止血浆蛋白滤出。透射电镜

whichisabout0.1μmthick.Permeableforsubstanceswhosemoleculeweightarelessthan70kDa.fluidthatpassedfiltrationmembraneintocapsularspacenamedpro-urine原尿（180L/d;125ml/m).Filtrationmembrane

滤过膜blood-urine

barrierfiltrationbarrier:composedofendothelia,basementmembraneand

slitmembrane裂孔膜,通过滤过膜流到肾小囊腔的液体称原尿（180L/d;125ml/min)。滤过膜受损：蛋白质通过→蛋白尿红细胞通过→血尿Renaltubule肾小管单层上皮性小管，近端接肾小囊，远端接集合管，有重吸收原尿中大部分成分和排泄的作用，分：近端小管proximaltubule

细段thinsegment

远端小管distaltubuleproximalconvolutedtubule（近曲小管）

LM：LocatedincorticallabyrinthsorrenalcolumnsSmallandirregularlumen;large,cuboidalcellswithundistinguishedboundariesAcidophilicBrushborder刷状缘

Basalstriations纵纹

EM：microvilli微绒毛

（brushborderunderLM）abundantplasmamembraneinfolding质膜内褶

（光镜下纵纹）andmitochondrialateralextensions侧突

cellmembranedepressed→smallvesiclesandtubuleslysosome、phagocytoticvesicles。Locatedinmedullaryrayandrenalpyramid,thestructuresimilartoproximalconvolutedtubule.EM：lower，microvilli、lateralextensionsandplasmamembraneinfolding↓↓Functionofproximaltubule：Reabsorb：85%H2O、nearlytotalglucose葡萄糖、aminoacid氨基酸；aswellas65%Na+and50%urea尿素。Secrete:H+、ammonia氨、creatinine(肌酐)andhippuricacid(马尿酸)etal。2）.proximalstaighttubule（近直小管）LM：locatedinmedullaryrayandrenalpyramidthin;simplesquamousepithelium。

weakacidophilic3)Thinsegment细段EM：fewmicrovilli、plasmamembraneinfolding，organells。Function：有利于水和离子通过4）Distalstaighttubule（远直小管）LM：Locatedinmedullaryrayandrenalpyramidsimplecuboidalepithelium,distinguishedcellboundaries；pale-stainedplasma；nobrushborderBasalstriationsEM：plasmamembraneinfoldingsandmitochondria基部质膜上有丰富的Na＋、K＋-ATP酶，能主动向间质转运Na＋，细胞膜还可能有一种呈凝状不通透水的酸性糖蛋白，致使水不能通过，因此造成从肾锥体底至肾乳头的间质内的渗透压逐步增高，有利于集合小系对水的重吸收。5）convolutedtubule（远曲小管）Locatedincorticallabyrinths，similartodistalstraighttubule,afewBasalstriations远曲小管是离子交换的重要部位，细胞有吸收水、Na＋和排出K＋、H＋、NH3等作用，对维持体液的酸碱平衡起重要作用。Adjustbyaldosterone醛固酮

andantidiureticH抗利尿激素使尿液浓缩，尿量减少

Functionofdistaltubule:ContinuereabsorbH2OandNa+Secrete:K+、H+andammoniaetal，tomaintainacid－baseandelectrolureequilibrationofbodyfluid近曲小管与远曲小管光镜结构的区别远曲小管近曲小管胞质嗜酸性弱、色淡强、色深细胞分界清楚不清楚管壁与管腔壁薄、细胞小，腔大而规则壁厚、细胞大，腔小而不规则刷状缘无明显基底纵纹不清楚清楚Arched～→straight～→papillarySimplecuboidal→columnar,pale-stainedplasma,distinguishedcellboundaries,neuclousroundandcentral-locatedReabsorbH2OandNa+，SecreteK+，NH3，

adjustbyaldosterone醛固酮

andantidiureticH抗利尿激素.C.Collectingtubuleandduct集合小管:

Juxtaglomerularapparatus球旁复合体:

Locateatvascularpoles.有球旁细胞、球外系膜细胞和致密斑排成三角形，入球微动脉和出球微动脉构成三角形的两边，致密斑构成底边，球外系膜细胞位于三角区的中心。juxtaglomerularcell球旁细胞LM:Afferentarteriole入球微动脉

Smoothmusclecells↓EM:rib、rERGolgiSecreteGFunction:

renin

肾素。angiotensinogen血管紧张素原

angiotensinIangiotensinIIbloodvesselcontractbloodpressure↑aldosterone醛固酮↑bloodvolum↑,bloodpressure↑reninEpithelium–likecell:large,cuboidal,basophilicMaculadensa致密斑Location:distaltubule,nearthevassularpoleLM：high,narrow,closenucleus→topEM：base→smallprocessdiscontinuousbasementmembrane。Function：Na+receptor离子感受器

感受远端小管内滤液的Na＋浓度变化。当滤液内Na＋浓度降低时，致密斑细胞将“信息”传递给球旁细胞，促进球旁细胞分泌肾素，增强远端小管储Na＋排K＋作用。

3.Extraglomerularcells:球外系膜细胞LocatebetweenmaculadensaandBowman’scapsule.Havegapjunctionswithmesangialcellsandjuxtaglomerularcells.可能传递信息.4.peripolarcell

极周细胞肾小囊壁层转折为脏层处细胞内含膜包颗粒释放入肾小囊腔，调节肾小管的重吸收和分泌功能肾的血液循环血液循环的主要通路

肾A

肾V叶间A

直小V

叶间V弓形A

球后毛细血管网

弓形V小叶间A

直小A

小叶间V

入球微A

球后毛细血管网肾小球毛细血管网

出球微A特点：肾动脉起源于腹主动脉，血流量大，4-5分钟滤过一遍。两次形成毛细血管网，球后毛细血管网胶体渗透压高，有利于肾小管