ureter

The ureter begins at the narrowed part of the renal pelvis and ends at the opening into the bladder. The function of the ureter is to drain urine from the kidney into the bladder. The ureter is shaped like a tube 30-35 cm long and up to 8 mm wide. There are three places in the ureter where there are narrowings: at the beginning of the ureter, where the abdominal part of the ureter passes into the pelvic part, where the pelvic border line intersects, and where the ureter enters the bladder. The width of the ureter lumen in these places is 3-4 mm. The ureter lies retroperitoneally. The following parts are distinguished in the ureter: abdominal, pelvic, and intramural.

The abdominal part (pars abdominalis) lies on the anterior surface of the psoas major muscle. The beginning of the right ureter is behind the descending part of the duodenum, and the left - behind the duodenojejunal flexure. In front of the ureter are the testicular (ovarian) artery and vein, the parietal peritoneum. When passing into 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 pelvic) of the right ureter is located in front of the right internal iliac artery and vein, and the left one is 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 medial to the obturator artery and vein. The lumen of the ureter in the pelvic part is narrowed. In women, the pelvic part of the ureter passes behind the ovary, then the ureter laterally bends around the cervix, passes in front of the uterine artery, and then lies between the anterior wall of the vagina and the bladder. In men, the pelvic part of the ureter is located outside the vas deferens, then crosses it and enters the bladder slightly below the upper edge of the seminal vesicle. The final section of the pelvic part of the ureter, which pierces the wall of the bladder in an oblique direction for 1.5-2.0 cm, is called the intramural part.

The walls of the ureter consist of three membranes. The inner mucous membrane (tunica mucosa) forms longitudinal folds. The middle muscular membrane (tunica muscularis) in the upper part of the ureter consists of two muscular layers - longitudinal and circular, and in the lower part - of three layers: longitudinal internal and external and middle circular. On the outside, the ureter has an adventitial membrane (tunica adventitia).

Vessels and nerves of the ureter

The arteries of the ureter originate from several sources. In the upper part, the ureter receives ureteric branches from the renal and ovarian (testicular) arteries. The middle part of the ureter is supplied with blood by ureteric branches from the abdominal aorta, from the common and internal iliac arteries. The lower part of the ureter receives branches from the middle rectal and inferior vesical arteries. The veins of the ureter flow into the lumbar and internal iliac veins.

The lymphatic vessels of the ureter drain into the lumbar and internal iliac lymph nodes.

The nerves of the ureter originate from the renal, ureteral and inferior hypogastric vegetative plexuses. Parasympathetic innervation of the upper part of the ureter is carried out by branches of the vagus nerve (via the renal plexus), and the lower part - by the pelvic visceral nerves.

X-ray anatomy of the ureters

On the radiograph, the ureter looks like a narrow shadow with clear and smooth contours. Upon exiting the renal pelvis, the right and left ureters approach the transverse processes of the lumbar vertebrae, forming a bend in the lumbar part to the medial side. In the pelvic cavity, the ureters are curved to the lateral side. Before entering the bladder, the ureters are again curved medially. When examining the ureters in a living person, in addition to the described anatomical constrictions, physiological constrictions associated with the peristalsis of the ureters can be seen.

The ureters in newborns have a tortuous 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.