The definitive ureters are the two tubes that convey urine from the kidneys to the bladder . They are formed when the renal pelvis narrows as it leaves the hilum of the kidney. Having passed retroperitoneally, along the posterior abdominal wall, each ureter enters the pelvis by crossing the pelvic inlet, approximately where the common iliac artery divides into the internal and external iliac arteries. It then passes inferiorly and anteriorly, along the pelvic wall, before turning medially, to enter the bladder. Just before reaching the bladder, the ureter in the male passes posterior to the vas deferens. In the female, the ureters pass posterior to the ovaries and along the base of the broad ligament, where they are crossed anteriorly by the uterine arteries. Both ureters have constrictions where stones could potentially lodge:
- where the pelvis of the ureter narrows
- where the ureter crosses the pelvic brim
- where it enters the bladder
Their autonomic nerve supply is via the renal, gonadal and hypogastric plexuses. Pain fibres accompany the sympathetic nerves and enter roughly the T12-L2 segments of the spinal cord. Pain arising from a kidney stone passing through the ureter is often referred to the scrotum or labia majora.