Show pageOld revisionsBacklinksBack to top This page is read only. You can view the source, but not change it. Ask your administrator if you think this is wrong. ====== DEVELOPMENT OF UROGENITAL SYSTEM ====== * Intermediate Mesoderm extends on each side of primitive dorsal aorta * bulging on posterior abdominal wall lateral to dorsal mesentery * आद्य मूत्रजनांग कटक ( urogenital ridge ) * Lateral Nephrogenic Cord * extends from cervical to thoracic segments , each segment called nephrotome * rest of unsegmented column , known as nephrogenic cord * development and dissapearnace ( ONTOGENY REPEATS PHYLOGENY ) * firstly propnephros ( upper cervical and thoracic segments ) * pronephros dissapears except its duct * from Solid cellular cord of cells * acquires a lumen called as nephrocele * evagination from dorsal wall * grows laterally and then caudal backwards * downturned ends join to form single primary excretory or pronephric duct * bends in to urorectal septum * opens in to ventral part of cloaca * other end is present close to peritoneal funnel * external glomerulus of capillaries project in to dorsal wall of coelom * internal glomerulus * metabolic wastes are liberated through these * 7-8 segmentally arranged pronephric tubules * Secondly mesonephros ( thoraco-lumbar direction ) * cephalic part of mesonephros dissapears * caudal part shifts alleigance to genital system * in males it forms the duct system of testes * in females it forms part of broad ligament * 70-80 Mesonephric tubules appear serially * laterally opens in to pronephric duct * mesonephric duct or wolffian duct * medial end does not communicate with coelomic cavity * internal glomerulus by a dilated blind end * mesonephric tubules become S-shaped * medial secretory part lined by columnar cells * lateral collecting part lined by cuboidal cells * each segment contains one mesonephric tubule and one glomerulus * tracing caudally each contains 3 or more tubules * each tubule is connected to numerous glomeruli * proximal mesonephric tubules start disappearing around 5 th week * ureteric bud develops from the mesonephric duct * its distal end dilates and invades nephrogenic cord * it shifts from dorsomedial to dorsolateral side * cap like investment called metanephric blastema * distal dilated end divides in to cranial and caudal parts * future major calyxes * the main duct connecting ureteric bud and mesonephric duct to cloaca is called * common excretory duct * around 8 th week 26 tubules and a single duct persist * Thirdly metanephric blastema ( lumbo-sacral region ) * retained as the permanent kidney * * मध्य जननांग कटक ( Medial Genital Ridge ) * Cloaca * आद्य मूत्रजनन गुहा (Primitive urogenital sinus) * vesico-urethral canal * urinary bladder * primitive urethra * निश्चित मूत्रजनांग गुहा ( Definitive urogenital sinus ) * pelvic part * phallic part {{::anatomy:urogenital-develop.png}} {{::anatomy:urogenital-develop-2.png}} {{::anatomy:urogenital-develop-3.png}} en/development-of-urogenital-system.txt Last modified: 2023/06/21 10:13by 127.0.0.1