The relationship of the genital and urinary systems in embryological development

The genital apparatus development associates with the urinary system development. It has origin in the intermediate mesoderm and urogenital sinus. The primordial germ cells share in the formation of the gonads. In males, the development of the testes is closely tied with that of the mesonephros. On the contrary the mesonephros has no role in females.

The urogenital ridge (crista urogenitalis) lies on both sides of the midline between the lateral mesoderm and the root of the dorsal mesenterium of the embryo. The urogenital ridge is originated from intermediate mesoblast. It consists of two main components, the the genital ridge and nephrogenic cord where the urinary apparatus take place. The genital ridge extends from the upper thorax region to the level of the cloaca. The cranial and caudal parts of the urogenital ridge form the upper and lower gonadal bands, respectively.

After the mesonephros has atrophied, the lower gubernaculum inserts at the lower pole of the gonad, extends to the inguinal region and, in a man, thus forms the gubernaculum and, in women, the ovarian ligament and round ligament (ligamentum teres uteri). After the atrophy of the mesonephros, the upper gubernaculum disappears (in men) while in women, the suspensory ligament of ovary is formed, which extends from the upper pole of the ovary towards the back and upwards into the lumbar region.