During a dissection, Arnie saw the ureters entering the lateral corners of the bladder but found the internal openings of the ureters in the trigone near the midline of the bladder. His observation necessarily means that
A) the ureters run medially for some distance within the posterior bladder wall.
B) the ureters and urethra are really the same tube.
C) each ureter must have four distinct openings into the bladder.
D) this bladder had a congenital defect.

Question

Quizplus · Accepted Answer

Arnie's observation indicates that the ureters enter the bladder on the lateral corners (sides), but the internal openings of the ureters are in the trigone, which is a triangular area defined by the two ureteral orifices and the internal urethral orifice near the midline of the bladder base. This means that the ureters must run medially for some distance within the posterior bladder wall to reach their internal openings in the trigone. This is a normal anatomical feature and not indicative of a congenital defect or that the ureters and urethra are the same tube. There are two openings for each ureter, one on each side, making a total of four openings for both ureters.

During a Dissection, Arnie Saw the Ureters Entering the Lateral