《泌尿生殖发生》课件.ppt

泌尿系统和生殖系统的发生,DEVELOPMENTOFUROGENITALSYSTEM,Keypoints1.Developmentofkidneyandureter;2.Septationofcloaca;3.Developmentofbladderandurethra;4.Malformationoftheurinarysystem;5.Developmentofgonads;6.Developmentofgenitalducts;7.Malformationofthegenitalsystem.,掌握的内容1肾和输尿管的发生；2泄殖腔的分隔及膀胱和尿道的发生；3多囊肾和脐尿瘘的形成。4原始生殖细胞的发生和迁移；5睾丸和卵巢的发生；6生殖管道的演变；7隐睾和先天性腹股沟疝的形成。,起源第三周间介中胚层(mesoderm)头侧生肾节（nephrotome）前肾腹、尾侧生肾索(nephrogeniccord)尿生殖生殖嵴(urogenitalridge)内：生殖腺嵴gonadalridge外：中肾嵴(mesonephricridge)中肾,Inthethirdweektheintermediatemesodermformsnephrotomesinthecervicalpartandnephrogeniccordsintheremainpart.Nephrogeniccordsincludemesonephricridgeandgonadalridge.,原基生肾节前肾（nephrotome）生肾索中肾、后肾(nephrogeniccord),肾的原基,一、泌尿系统的发生,（一）肾和输尿管的发生1前肾（pronephros）4周初，在第714体节外的生肾节内发生,由前肾小管(pronephrictubule)+前肾管(pronephricduct)组成。第4周末,前肾退化。,PronephrosComefromnephrotomesStructureafewpairsofpronephrictubulesapairofpronephricductsRegressesbytheendofweek4ofdevelopmentandarenotfuncitonalinhumans.,2中肾(mesonephros)4周末，1428体节外的生肾索中肾嵴内80对中肾小管(mesonephrictubule)+1对中肾管（mesonephricduct，Wolffianduct）,中肾小管呈S形内侧：肾小囊血管球肾小体外侧：通入中肾管,第10周，大部分中肾小管消失；中肾管保留，与泄殖腔接通。,Mesonephros,ComefrommesonephricridgesStructuremesonephrictubulesandmesonephricduct(wolffianduct)Itispartiallytransitoryandisfunctionalforashortperiod.,原基中肾管末端输尿管芽(uretericbud)生肾索尾段生后肾原基（组织）(metanephrogenicblastema),3后肾(metanephros)和输尿管的发生,输尿管芽（uretericbud）反复分支，形成输尿管、肾盂、肾盏、乳头管和集合管。,外周部分分化形成肾的被膜内侧部分形成肾小管和肾小囊近端小管头端凹陷形成肾小囊，与背主动脉分支形成的毛细血管形成肾小体；远端小管和集合管接通。,生后肾组织(metanephrogenictissue),Metanephrosbegintoformatweek5andisfunctionalinthefetusataboutweek10ofdevelopment.,人类的永久肾为后肾，形成后由盆腔内移至腰部。,前肾、中肾、后肾发生示意图,后肾发生示意图,后肾发生示意图,后肾发生示意图,后肾发生示意图,uretericbudandmetanephrogenictissueuretericbud:ureter,Renalpelvis,calyx,andcollectingtubulesetal.metanephrogenictissue：thecapsulesofthekidney,renalcapsulesandrenaltubules.renalcorpuscle:renalcapsuleandglomerulusTheendofdistaltubulecontactswithcollectingtubule,twotubulessooncommunicate.,Matenephros,（二）膀胱和尿道的发生1泄殖腔的分隔后肠末端的膨大部分称泄殖腔(cloaca)，人胚第7周，后肠与尿囊间的间充质增生，形成尿直肠隔(urorectalseptum)，尿直肠隔向下沿伸与泄殖腔膜会合，将泄殖腔分为背腹两部分：背侧：原始直肠(primaryrectum)分化为直肠和肛管上段腹侧：尿生殖窦(urogenitalsinus)分化为膀胱、尿道和阴道前庭,泄殖腔的分隔,CloacaCloacaisformedbydilationofterminalpartofhindgutwhichconnectswithallantoisandisclosedbythecloacalmembrane.Theurorectalseptumdividescloacaintourogenitalsinusandprimaryrectum.,2尿生殖窦(urogenitalsinus)的分化上段膀胱大部。膀胱三角来源于中肾管，尿囊根部参与膀胱形成。中段女性尿道大部份男性尿道的前列腺部和膜部。下部女性尿道小部份和阴道前庭男性尿道的海绵体部。,尿生殖窦的分化,（三）先天畸形多囊肾、异位肾、马蹄肾、肾缺如、双输尿管、脐尿瘘、膀胱外翻等,(1)多囊肾(polycystickidney)肾含许多囊泡，可引起肾功能衰竭集合小管发育异常或与肾单位未接通,(2)异位肾(ectopickidney)肾未正常上升，常见停留于盆腔。,(3)马蹄肾(horseshoekidney)两肾未上升，尾端融合，位置低。易发生尿路梗阻或感染。,异位肾,马蹄肾,马蹄肾,(5)双输尿管(doubleureter)输尿管芽过早分支（完全或部分）两条输尿管，或输尿管分叉。,(4)肾缺如(renalagenesis)输尿管芽未发生或未能诱导后肾发生，单侧多见。,双输尿管及输尿管分叉,(6)脐尿瘘(urachalfistula)尿囊（脐尿管）未闭锁尿液可从脐漏出,脐尿瘘,二、生殖系统的发生,原基：间介中胚层分期：未分化期性分化期性分化的决定自然倾向女性两次干预男性生殖腺睾丸生殖管道和外生殖器男性,睾丸决定因子(YSRY蛋白),雄激素,“不一样,就是不一样”,（一）原始生殖细胞的发生和迁移第1921天，卵黄囊壁的内胚层发生原始生殖细胞（primodialgermcell)。第25天原始生殖细胞沿背侧肠系膜向生殖腺嵴迁移。第6周原始生殖细胞进入初级性索。第7周生殖腺可分辨出睾丸或卵巢。,原始生殖细胞的发生和迁移,（二）生殖腺的发生1未分化性腺的发生生殖腺嵴表面上皮初级性索(primarysexcord),2决定性别分化的因素未分化生殖腺称性腺(gonad),性腺的分化取决于原始生殖细胞是否含有Y染色体。原始生殖细胞核的Y染色体短壁上有性别决定区（sexdeterminingregionoftheY,SRY)，其产物为睾丸决定因子（testis-determiningfactor,TDF)。在TDF的作用下，生殖腺分化为睾丸。若无TDF表达，则性腺就会自然地分化为卵巢。,初级性索生精小管索生精小管、直精小管和睾丸网表面上皮下的间充质白膜生精小管之间的间充质睾丸间质,3睾丸的发生第78周,10周初级性索退化次级性索（secondarysexcord)或称皮质索(corticalcord)孤立的细胞团卵泡细胞原始生殖细胞卵原细胞原始卵炮,4卵巢的发生,第5个月,卵原细胞分化为初级卵母细胞。,5睾丸和卵巢下降第78个月睾丸到达阴囊第3个月卵巢到达盆腔,（三）生殖管道的发生,性未分化期中肾管（Wolffianduct）中肾旁管(Mllerduct)中肾旁(paramesonephricduct)管尾端突入尿生殖窦的后壁形成窦结节,2.性分化期,男性中肾管发育成附睾管、输精管和射精管。中肾小管形成睾丸输出小管.中肾旁管退化,B.女性中肾旁管发育成输卵管和子宫。窦结节阴道板阴道中肾管退化,子宫和阴道的形成示意图,3.生殖管道发生的决定因素雄激素使中肾管发育；支持细胞分泌抗中肾旁管激素。无雄激素和抗中肾旁管激素,中肾旁管发育。,TheparamesonephricductsThecephalicportionbecomestheuterinetubes.Thefusedportion,theuterovaginalcanal,becomestheuterusandtheupper1/3ofthevagina.,Themesonephricductsdevelopintotheepididymis,theductusdeferens,ejaculatoryduct,andtheseminalvesicles.Theductusefferentescomefrommesonephrictubules.,头端:1个生殖结节(genitaltubercle)两侧:1对尿生殖褶(urogenitalfold)-尿道沟-尿生殖膜1对阴唇阴囊隆起(labio-scrotalswelling),(1)未分化期(原基),四、外生殖器的发生,(2)性别分化男性(A)女性(无A)生殖结节阴茎阴蒂尿生殖褶尿道海绵体部小阴唇尿生殖沟阴道前庭阴唇阴囊隆起阴囊大阴唇,外生殖器的性别分化,（五）先天畸形,先天性腹股沟疝（Inguinalhernia）,隐睾（Cryptorchidism）,子宫、阴道畸形模式图A.双子宫双阴道B.双子宫单阴道C.中隔子宫D.双角子宫E.阴道闭锁,两性畸形(hermaphroditism),假两性畸形生殖腺为睾丸（男）或卵巢（女）外生殖器更像相对性别,真两性畸形有两性性腺外生殖器呈间性罕见,真两性畸形,男性假两性畸形:雄激素分泌不足,女性假两性畸形:雄激素分泌过多(肾上腺生殖综合征),男性假两性畸形，外生殖器像女性,女性假两性畸形，体格和外生殖器像男性,雄激素不敏感综合征(androgeninsensitivitysyndrome)染色体为44+XY睾丸常在腹股沟部，无精子发生体细胞缺乏雄激素受体,雄激素不敏感综合征,外生殖器呈女性，有女性第二性征，但无输卵管、子宫。,OUTLINEFunctionallytheurogenitalsystemcanbedividedintotwoentirelydifferentcomponents:theurinarysystemandthegenitalsystem.Embryologicallyandanatomically,however,theyareintimatelyinterwoven.Bothsystemsdevelopfromintermediatemesodermalongtheposteriorwalloftheabdominalcavity,andinitiallytheexcretoryductsofbothsystementeracommoncavity,thecloaca.,Thekidneysareformedinthreetypes:thepronephros,mesonephros,andmetanephros.Thepronephrosisrepresentedbyafewpronephrictubulesandpronephricductsintheneck.Thepronephrossoondegenerate.However,thepronephricductspersistandutilizedbythenextsetofkidneys.Themesonephroswhichforminthethoracicandlumbarregions,islargeandcharacterizedbyexcretoryunits(nephrons)anditsowncollectingduct,themesonephricorwolffianduct.Inhumanitmayonlyfunctionbriefly,mostofthesystemdisappears.Inmale,theductsandapartoftubulesofthemesonephrosformtheconductingductsforspermfromthetestestotheurethra.Infemale,theseductsandtubulesregress.,Themetanephrosorpermanentkidneysappearinthefifthweek.Themetanephrosdevelopfromtwosources：uretericbud(anoutgrowthofthemesonephricduct)andmetanephrogenictissue.Metanephrogenictissueformsrenalcapsulesandrenaltubules.Andthecollectingsystemoriginatesfromtheuretericbud.Thisbudalsogivesrisetotheureter,renalpelvis,calyces.Connectionbetweenrenaltubuleandthecollectingtubuleisimportantfornormaldevelopment.,Thegenitalsystemconsistsofgonadsorprimitivesexglands,genitalducts,andexternalgenitalia.Allthreecomponentsgothroughanindifferentiationstageinwhichtheymaydevelopintoeitheramaleorafemale.Sexdifferentiationisacomplexprocessthatinvolvesmanygenes.ThekeytosexualdimorphismistheYchromosome,whichcontainstheSRY(sex-determiningregiononY)geneonitsshortarm.TheSRYproteinisthetestis-determiningfactor;underitsinfluencemaledevelopmentoccurs;initsabsencefemaledevelopmentisestablished.,Thetestis-determi