ABSTRACT
The urogenital system develops from the intermediate mesoderm. During folding of the embryo in the horizontal plane, this mesoderm is carried ventrally; then, a longitudinal ridge of mesoderm, the urogenital ridge, forms on each side of the dorsal aorta. This structure will eventually give rise to parts of the urinary and genital tract. The part of urogenital ridge giving rise to the urinary system is the nephrogenic cord; the part giving rise to the genital system is the genital ridge.1
