Embryology of the Genital Organs Per Brodal Institutt for medisinske basalfag Universitetet i Oslo 9th Semester 2008
The Mesonephric Duct Cloaca Mesonephros Metanephros Mesonephric duct Ureter bud 34 days (~ 5 weeks) 6 mm CR-length Mesonephric excretory tubules 2 P. Brodal
Early Gonadal Development Primordial germ cells Yolk sac Gonadal ridge Coelomic cavity Mesonephric duct Mesonephric ridge 3 P. Brodal
Early Development of The Internal Genitals 4 P. Brodal Neural tube Dorsal aorta Notochord Dorsal mesentery Coelomic cavity Mesonephric duct Mesonephric tubules Gonadal (genital) ridge
The Gonadal Ridge 4 week embryo Langman Gonadal ridge Primitive sex cords Proliferating coelomic epithelium Mesonephric duct 6 week embryo 5 P. Brodal
Further Development - Male Tunica Albuginea Testis cords 6 P. Brodal
Undifferentiated stage (6 w) Mesonephric tubules Gonadal anlage Mesonephric duct (Wolff’s duct) ♂ Paramesonephric duct (Müller’s duct) ♀ Urogenital sinus (from the cloaca) Primordia of accessory glands 7 P. Brodal Netter
Male and Female Gonadal Development The mesonephric duct The paramesonephric duct Medullary sex cords 8 P. Brodal MaleFemale
The Female Genital Tract – Further Development 9 P. Brodal
Malformations of the Uterus 10 P. Brodal
Development of the Urogenital Sinus Allantois Cloaca Rectum Future bladder Definitive urogenital sinus Defective partitioning of the cloaca results in anomalies of anorectal, urinary or genital structures; e.g rectourethral fistula or rectovaginal fistula 11 P. Brodal
Further development 12 P. Brodal Netter
External Genitals 4 weeks 6 weeks Genital tubercle Cloacal fold Cloacal membrane Urogenital membrane Urogenital fold 5 monthsNewborn 13 P. Brodal
Hypospadia 14 P. Brodal
Descent of the Testes Scrotum Peritoneum Retentio testis (kryptorchismus): When the testes do not reach the scrotum Inguinal hernia when tunica vaginalis still communicates with the peritoneal cavity (processus vaginalis persists) 15 P. Brodal