part of develops from contributes to morphology of embryonic cloaca primitive urogenital sinus NCIT:C34322 Wikipedia:Definitive_urogenital_sinus EHDAA:5029 UGS EMAPA:17379 urogenital sinus VHOG:0000414 SCTID:50961009 fetal UGS EHDAA2:0004060 sinus urogenitalis The ventral part of the cloaca remaining after septation of the rectum, which further develops into part of the bladder, part of the prostatic part of the male urethra and the urethra and vestibule in females. EHDAA:5919 embryonic structure intermediate mesoderm