ureterek

Ureters are a pair of slender, muscular tubes that transport urine from the renal pelvis of each kidney to the urinary bladder. In adults they measure about 25–30 cm in length and are located retroperitoneally along the posterior abdominal wall, descending along the psoas major muscle before crossing the bifurcation of the common iliac arteries and entering the bladder at the ureterovesical junction.

Anatomy and tissue: Each ureter consists of a mucosal lining of transitional epithelium, a thick muscular layer arranged as an inner longitudinal and an outer circular layer, and an outer connective tissue adventitia. The lumen remains largely collapsed until peristaltic waves move urine toward the bladder. The ureters have three segments: abdominal, pelvic, and intramural (within the bladder wall).

Blood supply and innervation: The upper ureter receives branches from the renal and nearby aortic sources; the middle portion from the common iliac or gonadal arteries, and the lower portion from the internal iliac or superior vesical branches. Innervation is via autonomic fibers from the renal and aortic plexuses and hypogastric/pelvic plexuses, providing sympathetic and parasympathetic input that modulates peristalsis.

Function and clinical relevance: The primary role is propulsion of urine by peristalsis. Obstruction or narrowing can cause hydronephrosis and flank pain. Common clinical issues include ureteric colic from calculi, ureteral strictures, tumors, or iatrogenic injury during pelvic or abdominal surgery. Diagnostic evaluation uses ultrasound, CT urography, MR urography, or ureteroscopy. Treatments range from analgesia and hydration to stenting, extracorporeal shock wave lithotripsy for stones, ureteroscopic stone ablative techniques, and surgical repair for strictures or injuries.