Ureter

Human body has two ureters, each of which is a muscular tube that extends from the corresponding kidney to the posterior surface of the urinary bladder. Urine is propelled along the ureters by peristaltic contractions of their muscular wall, aided by the filtration pressure of the glomeruli.

Structure:

Each ureter is about 10 inches long and lies in a vertical plane. Both ureters have three constrictions along the course (similar to the esophagus). The first constriction exists where the renal pelvis joins the ureter. The second occurs where it is kinked as it crosses the pelvic brim. And the third occurs where it pierces the wall of the bladder.

Course:

Within the kidney, the renal pelvis is the expanded upper end of the ureter. The ureter emerges from the hilum of the kidney and runs vertically downward on the psoas muscle, behind the parietal peritoneum. It enters the pelvis by crossing the bifurcation of the common iliac artery, in front of the sacroiliac joint. It continues downward until it reaches the ischial spine, where it turns forward to enter the lateral angle of the bladder.

Important relations:

Right ureter:

Anterior:

  • Duodenum
  • Terminal part of ileum
  • Right colic and ileocolic vessels
  • Right testicular (males) or ovarian (females) vessels
  • Mesentery of the small intestine

Posterior:

  • Right psoas muscle
  • Bifurcation of the common iliac artery

Left ureter:

Anterior:

  • Sigmoid colon
  • Sigmoid meoscolon
  • Left colic vessels
  • Left testicular (males) or ovarian (females) vessels

Posterior:

  • Left psoas muscle
  • Bifurcation of the left common iliac artery

Blood supply:

Arterial:

Ureter receives its arterial blood supply in three different parts, as explained below.

  • Upper part receives its blood supply from renal artery
  • Middle part receives its blood supply from testicular or ovarian artery
  • Pelvic part receives its blood supply from the superior vesical artery

Venous:

The venous blood is drained by veins that correspond to the arteries explained above.

Lymph drainage:

Lymph from the ureters drains into the lateral aortic nodes and the iliac nodes.

Nerve supply:

Ureters receive their nerve supply from renal, testicular (or ovarian) and hypogastric plexuses.

Afferent (sensory) fibers travel with the sympathetic nerves and enter the spinal cord in the first and second lumbar segments.