<prompt> The interureteric ridge forming the base of trigonal structure is also calledBells muscleMerciers barRices barToldts bar  <response>: Interureteric fold: A fold of mucous membrane extending from the orifice of the ureter of one side to that of the other side. Also called Merciers bar. Bells muscle A band of muscular fibres, forming a slight fold in the wall of the bladder, running from the uvula to the opening of the ureter on either side, bounding the trigonium. Toldts fascia - fixation of fascial planes behind the body of the pancreas. 