The trigone of the bladder is a triangular area located at the base of the urinary bladder. It is bounded by three points: the two ureteric orifices, where the ureters enter the bladder, and the internal urethral orifice, where urine exits the bladder into the urethra.
This region is significant because it has a smooth surface and is structurally different from the rest of the bladder, which is lined with a more elastic mucosa that allows for expansion as the bladder fills with urine. The trigone remains fixed in position, making it a vital landmark during bladder surgeries or examinations.
Functionally, the trigone plays a role in bladder function and the urination process. The stretch receptors in the bladder wall help to indicate when the bladder is full, and the trigone’s location aids in signaling the appropriate time to urinate.