Editing Excretory system (section)

==== Ureter ====
{{Main|Ureters}}

The [[ureters]] are muscular ducts that propel urine from the kidneys to the [[urinary bladder]]. In the human adult, the ureters are usually {{convert|25|–|30|cm|in|round=0.5|abbr=on}} long. In humans, the ureters arise from the renal pelvis on the medial aspect of each kidney before descending towards the bladder on the front of the [[psoas major]] muscle. The ureters cross the pelvic brim near the bifurcation of the iliac arteries (which they run over). This "pelviureteric junction" is a common site for the impaction of [[kidney stones]] (the other being the uteterovesical valve). The ureters run posteriorly on the lateral walls of the pelvis. They then curve anteriormedially to enter the bladder through the back, at the vesicoureteric junction, running within the wall of the bladder for a few centimeters. The backflow of urine is prevented by valves known as ureterovesical valves. In the female, the ureters pass to the bladder through the mesometrium.