Trigone of urinary bladder develops from
The terminal poion of Mesonephric duct gets absorbed into the posterior wall of urogenital sinus and forms the trigone of the urinary bladder. Urinary bladder develops from endodermal vesicourethral canal. Ref: Gray's 39e/p-1289
Urogenital sinus
Vesicourethral canal
Mesonephric duct
Endoderm
General anatomy