Each ureter enters the pelvis by crossing in front of the common iliac vessels or the commencement of the external iliac vessels (Fig. 5.14). The ureter passes downwards and backwards before curving forwards to reach the posterior surface of the bladder. The ureter crosses the medial aspect of the obturator nerve and vessels and the superior vesical vessels before running forwards along the levatorani muscle. The pelvic peritoneum covers the medial aspect of the ureter and separates it from the rectum, sigmoid colon or coils of ileum.
In the male, the ureter passes under the ductus deferens and terminates near the seminal vesicle (Fig. 5.15). In the female, the ureter descends on the lateral pelvic wall, outside the peritoneum but close to the ovary as far as the ischial spine, where it turns medially across the pelvic floor to reach the base (root) of the broad ligament. Here it crosses under the uterine artery and passes close to the uterine cervix (Fig. 5.13). The ureter is vulnerable to damage during hysterectomy.