Ureter
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Direct answer
Each ureter is about 25 cm long and runs retroperitoneally from the renal pelvis at the hilum to the bladder, which it enters obliquely, creating a valvular mechanism that prevents reflux. It has abdominal, pelvic and intramural parts, with three classical narrowings — the pelviureteric junction, the pelvic brim and the vesicoureteric junction, the narrowest. These are exactly the sites at which stones impact.
What you must remember
- Abdominal course: descends on psoas major, crossed obliquely in front by the gonadal vessels, with the genitofemoral nerve behind it on the psoas.
- Pelvic brim: passes in front of the bifurcation of the common iliac artery over the sacroiliac joint — the second constriction and a useful surface landmark.
- Anterior relations: on the right, the duodenum, mesenteric root with the ileocolic vessels and the terminal ileum; on the left, the left colic and sigmoid vessels and the sigmoid mesocolon.
- Pelvic relations: in the male the vas deferens crosses above and in front of it; in the female the ureter runs in the broad ligament about 2 cm lateral to the cervix, passing below the uterine artery — water under the bridge.
- Intramural part: tunnels obliquely through the bladder wall for about 2 cm, so raised bladder pressure closes the lumen and prevents reflux.
- Blood supply: small segmental branches from the renal, gonadal, aortic, iliac, vesical and uterine arteries, anastomosing longitudinally in the adventitia.
- Clinical importance: ureteric colic radiates from loin to groin through its T11–L2 supply; the ureter is in danger at the pelvic brim and below the uterine artery during hysterectomy.
Common confusion
The narrowest point is the vesicoureteric junction, not the pelviureteric junction. Remember which structure crosses which — the uterine artery and the vas deferens both pass above the ureter, so the ureter always runs beneath. Being retroperitoneal throughout, an injured ureter leaks urine into the retroperitoneum, not the peritoneal cavity.
Exam-focused takeaway
For theory, draw the ureter from hilum to bladder, marking the three constrictions, the pelvic brim crossing and the uterine artery above it. In viva, expect the sites of stone impaction, the water under the bridge relation, and the segmental blood supply. For spotters, trace the ureter on a urogram, noting the narrowings and its crossing of the transverse processes.
Frequently asked questions
How long is the ureter and what are its parts?
About 25 cm, with abdominal, pelvic and intramural parts.
What are its three constrictions?
The pelviureteric junction, the pelvic brim where it crosses the common iliac bifurcation, and the vesicoureteric junction — the narrowest, where stones impact.
What is water under the bridge?
The ureter (water) passes below the uterine artery (bridge) in the base of the broad ligament, about 2 cm lateral to the cervix — the relation at risk in hysterectomy.
How does the ureter prevent reflux?
Its oblique course through the bladder wall lets raised intravesical pressure squeeze it shut, acting as a valve.
What is its blood supply?
Segmental branches from the renal, gonadal, aortic, iliac, vesical and uterine arteries, anastomosing along its length.
Why does ureteric colic radiate to the groin?
Its T11 to L2 nerve supply refers pain from the loin to the groin, testis or labium majus.