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. [ http://www.informatics.jax.org/accession/anna MP:0011768 ]
Synonyms: urinary bladder trigone deep trigone trigonum vesicae trigone of bladder bladder trigone musculus trigoni vesicae profundus vesical trigone Lieutaud's trigone
Term information
- SCTID:272663002
- NCIT:C12331
- EMAPA:35174
- galen:TrigoneOfUrinaryBladder
- UMLS:C0447586 (ncithesaurus:Bladder_Trigone)
- FMA:15910
- Wikipedia:Trigone_of_urinary_bladder
- MA:0002492
uberon_slim, pheno_slim, human_reference_atlas
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
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.