Ureter, bladder and urethra
The cloaca is subdivided by the urorectal septum into the primary urogenital sinus and the anorectal canal. The primary urogenital sinus develops further into the vesico-urethral canal, which gives rise to the bladder, parts of the urethra, and to the more caudally-situated definitive urogenital sinus; a pelvic part (narrow duct, proximal) and a phallic part (wide, distal) can be distinguished in this structure.