part of part of contributes to morphology of Homo sapiens organ part urinary bladder trigone of urinary bladder https://cdn.humanatlas.io/digital-objects/ref-organ/urinary-bladder-female/v1.2/assets/3d-vh-f-urinary-bladder.glb https://cdn.humanatlas.io/digital-objects/ref-organ/urinary-bladder-male/v1.2/assets/3d-vh-m-urinary-bladder.glb https://upload.wikimedia.org/wikipedia/commons/5/57/Illu_bladder.jpg Wikipedia:Trigone_of_urinary_bladder SCTID:272663002 The area is very sensitive to expansion and once stretched to a certain degree, the urinary bladder signals the brain of its need to empty. The signals become stronger as the bladder continues to fill. Lieutaud's trigone trigone of bladder FMA:15910 The smooth triangular region of the wall of the urinary bladder formed by the two ureteral orifices and the internal urethral orifice; it is an area in which the muscle fibers are closely adherent to the mucosa. musculus trigoni vesicae profundus vesical trigone urinary bladder trigone deep trigone bladder trigone UMLS:C0447586 NCIT:C12331 EMAPA:35174 trigonum vesicae urinariae dorsal bladder neck Embryologically, the trigone of the bladder is derived from the caudal end of mesonephric ducts, which is of mesodermal origin (the rest of the bladder is endodermal). In the female the mesonephric ducts regresses, causing the trigone to be less prominent, but still present UBERON:0001257 galen:TrigoneOfUrinaryBladder MA:0002492 trigonum vesicae fundus of urinary bladder