What are the anatomic boundaries of trigone bladder?

The trigone of the bladder is a smooth region between the two ureteric orifices, posteriorly bounded by the inter-ureteric fold extending into the roof of the bladder.

1. Superior boundary:

* Interureteric ridge connecting the two ureteric orifices.

2. Inferior boundary:

* The line through the 2 ureteric orifices and internal urethral orifice.

3. Lateral boundaries:

* Medial margin of ureteric orifices