Ureters

The ureter is a paired fibromuscular tube that conveys urine from the kidneys in the abdomen to the bladder in the pelvis.

Gross anatomy

The ureter is 25-30 cm long and has three parts:

  • abdominal ureter: from the renal pelvis to the pelvic brim
  • pelvic ureter: from the pelvic brim to the bladder
  • intravesical or intramural ureter: within the bladder wall
  • Course

    The ureter begins its descent to the bladder by running along the medial aspect of the psoas muscle. Here, the ureter lies anteriorly and slightly medial to the tips of the L2-L5 transverse processes.

    It enters the pelvis anteriorly to the sacroiliac joint at the bifurcation of the common iliac vessels (at the pelvic brim) and then courses anteriorly to the internal iliac artery down the lateral pelvic sidewall.

    At the level of the ischial spine it turns forward and medially to enter the posterolateral wall of the bladder, where it runs an oblique 1-2 cm course, before opening into the bladder at the internal ureteric orifice .

    Relations

    The relations of the ureter are somewhat complex due to the differences between the left and right sides of the abdominal cavity and differences between male and female pelvic viscera.

    Abdominal ureter

    Following the course of the ureter from superior to inferior :

    Pelvic ureter

    It should be noted that the only structures to anteriorly pass over the pelvic ureter is the ductus deferens in males and the uterine artery in females.

    Constrictions

    The ureter has a diameter of 3 mm but there are three constrictions, which are the most common sites of renal calculus obstruction:

    • at the pelviureteric junction (PUJ) of the renal pelvis and the ureter
    • as the ureter enters the pelvis and crosses over the common iliac artery bifurcation
    • at the vesicoureteric junction (VUJ) as the ureter obliquely enters the bladder wall
    Blood supply
    Lymphatic drainage
    • abdominal ureter: aorto-caval and common iliac nodes
    • pelvic ureter: internal and external iliac nodes
    Innervation
    • derived from renal, aortic and hypogastric autonomic plexuses

    Histology

    The ureteric wall is composed of three layers (from outside to inside):

  • adventitia
  • smooth muscle
  • transitional cell epithelium
  • Variant anatomy

    Related pathology