I Development ofUrinary System1. Development of Kidney and UreterMthreestages:Pronephrostransitory structureMesonephrosMetanephros→definitive kidney
1. Development of Kidney and Ureter ⅠDevelopment of Urinary System three stages: Pronephros Mesonephros Metanephros transitory structure definitive kidney
1.1Pronephros (forekidney):Nephromere → pronephric tubules and duct -pronephros → degenerates.VestigalpronephricsyslemMesonephrictubulesMesonephricsystemMesonephricductUreteric budMetanephricsystem
1.1 Pronephros (forekidney): Nephromere → pronephric tubules and duct → pronephros → degenerates
1.2Mesonephros:1) mesonephric ridge → mesonephric ductVestigalpronephricsystemMesonephrictubulesMesonephricsystemIntestinalloop-MesonephrosMesonephricductGonad--MesonephricductUreteric budMetanephricsystem
1.2 Mesonephros: 1) mesonephric ridge → mesonephric duct
2)Mesonephrictubules→mostdisappear1.Neuraltube5.Intestinaltube9.Mesonephric duct (Wolffianduct)10.Mesonephrictubule11.Urogenital ridge
1.Neural tube 5.Intestinal tube 9.Mesonephric duct (Wolffian duct) 10.Mesonephric tubule 11.Urogenital ridge 2) Mesonephric tubules → most disappear
1.3metanephros:definitivekidney1)Primordia: ureteric bud and metanephricblastemaHindgutMesonephrictissueAllantois-MesonephricductUrorectalseptumUretericCloaca-budMetanephricblastema
1.3 metanephros: definitive kidney 1) Primordia: ureteric bud and metanephric blastema