The combined structures composing the urinary and genital, or reproductive, organs of vertebrates. The terms urinogenital or genitourinary system are equally applicable and just as frequently used. During embryonic development, the urinary and reproductive systems are closely interrelated, as their ducts arise in associated mesodermal regions. Common passages are associated with both these systems in various vertebrates, such as the single orifice for emission of urine and sperm.