2. Efferent artery
3. Renal artery
4. Renal vein
5. Renal hilum
6. Renal pelvis
8. Minor calyx
9. Renal capsule
10. Inferior renal capsule
11. Superior renal capsule
12. Afferent vein
14. Minor calyx
15. Major calyx
16. Renal papilla
17. Renal column
|Gray's||subject #254 1225|
|Artery||Superior vesical artery, Vaginal artery|
In human anatomy, the ureters are the ducts that carry urine from the kidneys to the urinary bladder, passing anterior to the Psoas major. The ureters are muscular tubes that can propel urine along by the motions of peristalsis. In the adult, the ureters are usually 25-30cm long.
In humans, the ureters enter the bladder through the back, running within the wall of the bladder for a few centimetres. There are no valves in the ureters, backflow being prevented by pressure from the filling of the bladder, as well as the tone of the muscle in the bladder wall.
The ureter has a diameter of about 3 millimeters, and the lumen is star-shaped. Like the bladder, it is lined with transitional epithelium, and contains layers of smooth muscle.
The epithelial cells of the ureter are stratified (in many layers), are normally round in shape but become squamous (flat) when stretched. The lamina propria is thick and elastic (as it is important that it is impermeable).
There are two spiral layers of smooth muscle in the ureter wall, an inner loose spiral, and an outer tight spiral. The inner loose spiral is sometimes described as longitudinal, and the outer as circular, (this is the opposite to the situation in the gastrointestinal tract). The distal third of the ureter contains another layer of outer longitudinal muscle.
The adventitia of the ureter, like elsewhere is composed of fibrous connective tissue, that binds it to adjacent tissues.
Medical problems that can affect the ureter include:
The content of this section is licensed under the GNU Free Documentation License (local copy). It uses material from the Wikipedia article "Ureter" modified September 7, 2007 with previous authors listed in its history.