part of part of develops from develops from contributes to morphology of organ part urinary bladder urorectal septum fundus of urinary bladder EMAPA_RETIRED:18322 EHDAA:9330 urinary bladder fundus region fundus of bladder base of urinary bladder EHDAA2:0000582 Wikipedia:Fundus_of_the_urinary_bladder#Fundus bladder dome urinary bladder fundus SCTID:362226002 EMAPA:35173 MA:0001694 urinary bladder base VHOG:0001184 The base or posterior surface of the urinary bladder contains the trigone of the bladder and the outlet where urine empties through the internal urethral orifice. NCIT:C48939 FMA:15908 UBERON:0006082 urogenital sinus mesenchyme