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The ureter ( Latin ureter , from Greek Ουρητήρας) is one of the paired draining urinary tract and connects the kidneys with the urinary bladder . In the fetus it arises from the ureteral bud .


Course of the ureters viewed from behind. The color is used for highlighting and does not correspond to reality.

The ureter begins at the renal pelvis , a kind of funnel in which the urine filtered off and concentrated by the kidney is collected. The ureter bends by about 90 °. It then runs under the peritoneum ( retroperitoneally ) on the back wall of the abdominal cavity over the two terminal branches of the aorta (area where the common iliac artery bifurcates into the external and internal iliac arteries ) and opens into the urinary bladder. After entering the urinary bladder, the ostium ureteris , it runs a short distance inside the urinary bladder wall ( intramural ), which largely prevents reflux to the kidneys when the bladder is more full . This intramural course creates two converging folds ( Columnae uretericae , continued as Plicae uretericae ) in the urinary bladder mucosa, which delimit the urinary bladder triangle ( Trigonum vesicae ).

Ureteral crossings

On its way it crosses under the testicular or ovarian vessels ( A./V. Testicularis or A./V. Ovary ) on the musculus psoas major , further caudal in its course it crosses the arteria iliaca communis or arteria iliaca externa and im In the small pelvis, shortly before entering the wall of the urinary bladder, it crosses the vas deferens or the uterine artery .

Ureteral narrowing

In the three named places

  • Exit from the renal pelvis,
  • Crossing of the common iliac artery or the external iliac artery and
  • Entry into the urinary bladder

the ureter narrows. The place where the testicular or ovarian vessels cross the ureter is often referred to as the fourth constriction.


Section through a ureter
(from Gray's Anatomy )

The ureter shows the typical structure of a membranous, muscular tube with an inner mucous membrane ( tunica mucosa , mucosa), a muscle layer ( tunica muscularis ) made of smooth muscles and an outer connective tissue anchoring layer ( tunica adventitia ).

In horses , mucous glands ( glandulae uretericae ) are embedded in the mucous membrane of the initial part, as well as in the renal pelvis . Therefore horse urine is viscous and stringy.


The kidney stones often get stuck in the above-mentioned bottlenecks . The ureter tries to transport the stones through spasmodic muscle actions, which is perceived as (kidney) colic . In older people, the ureter can be filled with stones. These stones have different sizes, the largest stone is then called the pilot stone .

In chronic infections, whitish plaques can build up on the ureter wall, which is known as malacoplakia .

As plant faults come Ureterstenosen ( ureteropelvic junction obstruction or distal ureteral stenosis ), an offset or expanded mouth of the bladder ( ureter , Ureterocele ) and partial or full duplex units of the ureter at the moment ( ureter fissus , Ureter ). Irregular mouth or drainage disorders can lead to reflux and inflammation, which can damage the kidneys or lead to an enlargement of the ureter ( hydroureter ), in the case of cystitis also to bilateral ureter enlargement described for the first time in 1937 by the Nuremberg urological surgeon Eduard Pflaumer (1872–1957).


  • Uwe Gille: urinary organs . In: Franz-Viktor Salomon et al. (Hrsg.): Anatomie für die Tiermedizin . Enke, Stuttgart 2004. ISBN 3-8304-1007-7
  • Schünke, Schulte, Schumacher et al .: Prometheus LernAtlas der Anatomie . Thieme, Stuttgart 2005. ISBN 3-13-139531-1

Individual evidence

  1. Eduard Pflaumer: Systemic disease and cystitis. In: Journal of Urology. Volume 31, 1937, pp. 330-333.
  2. ^ Horst Kremling : Eduard Pflaumer (1872-1957). A pioneer in urology. In: Würzburg medical history reports. Volume 14, 1996, pp. 81-84.

Web links

Wiktionary: ureter  - explanations of meanings, word origins, synonyms, translations