Ureter
Last reviewed: 20.11.2021
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The ureter starts from the narrowed part of the renal pelvis and ends up in the bladder. The function of the ureter is to remove urine from the kidney into the bladder. The ureter has the shape of a tube 30-35 cm in length and 8 mm in width. In the three places of the ureter there are constrictions: in the region of the beginning of the ureter, the transition of the ventral part of the ureter into the pelvic region, where the borderline of the pelvis crosses, and at the point of the ureteral flow into the bladder. The width of the lumen of the ureter in these places is 3-4 mm. The ureter lies retroperitoneally (retroperitoneally). In the ureter, the following parts are distinguished: abdominal, pelvic and intra-wall.
The abdominal part (pars abdominalis) lies on the anterior surface of the large lumbar muscle. The beginning of the right ureter is behind the descending part of the duodenum, and the left one behind the duodenum-jejunal crook. In front of the ureter are the ovarian (ovarian) artery and vein, the parietal peritoneum. When moving to the pelvic part, the left ureter lies behind the root of the mesentery of the sigmoid colon, and the right ureter crosses the root of the mesentery of the small intestine.
The pelvic part (pars pelvica) of the right ureter lies in front of the right internal iliac artery and vein, and the left one - in front of the common iliac artery and vein. In the pelvic cavity, each ureter is located in front of the internal iliac artery and is medial to the obstructive artery and vein. The ureteral lumen in the pelvic part is narrowed. In women, the pelvic part of the ureter passes behind the ovary, then the ureter passes from the lateral side around the cervix, passes anterior to the uterine artery, and then lies between the anterior wall of the vagina and the bladder. In men, the pelvic part of the ureter lies outside the seed of the outflowing duct, then crosses it and enters the bladder slightly below the upper edge of the seminal vesicle. The final part of the pelvic part of the ureter, perforating the wall of the bladder in an oblique direction for 1.5-2.0 cm, is called the intra-wall part.
The walls of the ureter consist of three membranes. The inner mucosa (tunica mucosa) forms longitudinal folds. The average muscular tunica (tunica muscularis) in the upper part of the ureter consists of two muscle layers - longitudinal and circular, and in the lower one - of three layers: longitudinal internal and external and medium circular. From the outside, the ureter has an adventitial tunic (tunica adventitia).
Vessels and nerves of the ureter
Arteries of the ureter come from several sources. In the upper part, the ureteral branches from the renal, ovarian (testicle) arteries approach the ureter. The middle part of the ureter is supplied with ureteral branches from the abdominal part of the aorta, from the common and internal iliac arteries. To the lower part of the ureter come the branches from the middle rectal and lower urinary bladder arteries. Veins of the ureter flow into the lumbar and internal iliac veins.
Lymphatic vessels of the ureter flow into the lumbar and internal iliac lymph nodes.
The ureter's nerves originate from the renal, ureteral and lower hypogastric vegetative plexuses. Parasympathetic innervation of the upper part of the ureter is carried out by the branches of the vagus nerve (through the plexus plexus), and the lower part - the pelvic internal nerves.
X-ray angiography
On the roentgenogram, the ureter has the appearance of a narrow shadow with clear and smooth contours. Upon exiting from the renal pelvis, the right and left ureters approach the transverse processes of the lumbar vertebrae, forming a median bend in the lumbar region. In the pelvic cavity, the ureters are curved laterally. Before entering the bladder, the ureters are again curved medially. With fluoroscopy of the ureters in a living person, in addition to the described anatomical constrictions, one can see physiological constrictions associated with peristalsis of the ureters.
The ureters in the newborns have a twisty course. The length of the ureter reaches 5-7 cm. By 4 years, its length increases to 15 cm. The muscular membrane of the ureter is poorly developed in early childhood.