ABSTRACT
During the fifth week of embryonic life the nephrogenic cord develops from the mesoderm and forms the urogenital ridge and mesonephric duct (later to form the Wolffian duct) (Fig. 2.1). The mesonephros consists of a comparatively large ovoid organ on each side of the midline, with the developing gonad on the medial side of its lower portion. The paramesonephric duct later forms the Müllerian system. The fate of the mesonephric and paramesonephric ducts is dependent on gonadal secretion. Assuming female development, the two paramesonephric ducts extend caudally to project into the posterior wall of the urogenital sinus as the Müllerian tubercle. The Wolffian system degenerates.
