The official name, apparatus urogenitalis, brings the urinary and reproductive organs together under one heading.

The chief justification for this convention lies in the common origin of certain elements of the two systems in the intermediate mesoderm and adjacent part of the celomic epithelium. Also, the urinary and reproductive systems of the adult share the final portions of the tracts, urethra in the male and the vestibule in the female.

Because of the close developmental associations of the urinary and reproductive systems, we have chosen in this chapter to precede the account of the adult anatomy with a review of the development. However, the general layout of the urogenital apparatus is provided in Figs. 5.1 and 5.2.