All true the trigone of the urinary bladder except
The trigone is a smooth triangular region of the internal urinary bladder formed by the two ureteral orifices and the internal urithral orifice.The area is very sensitive to expansion and once stretched to a ceain degree, the urinary bladder signals the brain of its need to empty. The signals become stronger as the bladder continues to fill.Embryologically, the trigone of the bladder is derived from the caudal end of mesonephric duct, which is of mesodermal origin. In the female the mesonephric ducts regresses, causing the trigone to be less prominent, but still present. Ref - bdc 6e vol2 p373 , semantischolar.org
Mucosa is loosely associated to the underlying musculature
Mucosa is smooth
It is lined by transitional epithelium
It is derived from the absorbed pa of the mesonephric duct
Abdomen and pelvis