One of the important parts of the excretory system, the ureters are often underrated and not much spoken of. However, no matter how much we ignore them, there absence is not something we want. In this article on ureter facts we are going to learn about the role they play in our body, the location where they can be found, their physical composition and more. So, without further ado, let us begin…
Interesting Ureter Facts: 1-5
1. Small and slender pair of tubes which help in transporting urine from kidneys to the urinary bladder are known as Ureters.
2. This pair of tubes is found in the abdominopelvic cavity1. A single ureter is of 10 to 12 inches or 25-30 centimeters long.
3. Left ureter is slightly longer than the right ureter because left kidney is placed slightly higher than the right kidney.
4. The width of the ureters is few millimeters. Having said that, it is important to note that the width of the ureter near the kidney is larger (width is nearly 10 millimeters) than the width of the ureter near the urinary bladder (width is merely 1-2 millimeters).
5. Ureters start at the exit of renal pelvis (funnel shaped dilated upper end of the ureter) from the renal hilus (the entry and exit point of the kidney). The junction where the pelvis of the kidney and ureters meet is called as the ureteropelvic junction or ureteral pelvic junction.
Interesting Ureter Facts: 6-10
6. Ureter is a retroperitoneal organ just like kidneys. Retroperitoneal organs are the organs which stay behind the peritoneum (serous membrane2 that lines the abdominal cavity). These retroperitoneal organs are lined by the peritoneum only on the anterior3 side.
7. They move through the abdominopelvic cavity’s walls staying posterior4 to the peritoneum. They then move towards the pelvis. The ureters pass through the common iliac arteries and veins and then move towards the urinary bladder at the base of the pelvis5.
8. In females, the ureters enter the mesometrium (mesentery of the uterus; mesentery is a set of tissues which attach uterus to the pelvic cavity) and pass from below the uterine arteries to reach urinary bladder.
9. The ureters enter the urinary bladder posteriorly. They enter the bladder obliquely through the bladder’s wall and reach nearly one inch or 2 centimeters into the urinary bladder. The junction at the which urinary bladder and ureters meet is known as the ureterovesical junction or ureter-bladder junction.
10. The apertures of the ureters present in the urinary bladder are nearly 1 inch in contracted bladder whereas in the inflated bladder, the size of the ureters’ apertures increases from 1 inches to 2 inches.
Interesting Ureter Facts: 11-15
11. There are three constrictions6 in ureter which are:
- At the junction of renal pelves (plural of pelvis) and ureters.
- At the place where ureters enter the pelvis and passes through bifurcation7 of common iliac arteries.
- At the junction of urinary bladder and ureters.
12. Ureters wall is made of 4 layers. They are:
- Mucosa – Innermost layer. It consists of transitional epithelium which has the ability to extend to accommodate differing volumes of urine passage. It also helps in preventing the waste from escaping into the body.
- Submucosa – Lines the mucosa. It consists of all the nerves, blood vessels, connective tissues and is responsible for supporting other layers.
- Muscularis – Consists of smooth muscles which helps the ureter to move.
- Adventitia – Outermost layer. It consists of loose connective tissue. It is attached to other organs in such a way that the ureters stay in place and at the same time giving it some freedom to move.
13. Ureters receive blood supply from many sources, which are noted below:
- Upper part of the ureters receive blood from renal arteries (when the ureters are close to the kidneys).
- Middle part of the ureters receive blood from branches of gonadal arteries and abdominal aorta and common iliac arteries.
- Lower part of the ureters receive blood from internal iliac arteries, middle rectal artery, superior vesical artery, internal vesical artery (only in males), vaginal arteries and uterine artery (only in females).
14. Ureters is connected with a lot of nerves. The pain that you sense in the back, scrotum (in males), sides of the abdomen, upper part of the thigh on the front side and labia majora (in females) may be because of the pain sensation of the ureters
15. Though the function of the ureters looks simple it is not really so. Gravity does some work to pull down the urine from kidneys when we stand. But what about when we are laying down or floating (as in the case of astronauts)? Ureters uses peristalsis (rhythmic movement of the smooth muscles) to push the urine down to the urinary bladder.
Interesting Ureter Facts: 16-20
16. When urinary bladder is filled with urine, the ends of the ureters (which have valves known as ureterovesical valves) are squeezed so as to prevent vesicoureteral reflux (urine going back into kidneys). It helps in preventing bacterial infections in this way.
17. The obstruction to ureteropelvic junction leads to hydronephrosis (urine filled renal pelvis). This can be corrected by Pyeloplasty (surgical reconstruction of the renal pelvis). There are other ways but Pyeloplasty is the most efficient way.
18. Injury to ureters is rare but not impossible. Car accidents, or penetrating injuries to the abdomen may damage the ureters. Hysterectomy (surgical removal of the uterus or other reproductive organs and surrounding organs) can also rarely damage the ureters.
19. Kidney stones may move to the ureters and block the passage of the urine thereby leading to hydronephrosis. The stones getting stuck in the ureters is most common at the constriction places (mentioned in the point 11).
20. Vesicoureteral reflux (urine going back into kidneys) can cause many UTI (Urinary Tract Infections). Ureters can get cancer as well, which is known as ureteral cancer.
Glossary of Terms
Abdominopelvic Cavity1: It refers to a body cavity that contains the abdominal cavity as well as the pelvic cavity. The abdominopelvic cavity is where the following organs are located:
- Most of the small intestine as well as large intestine
- Internal reproductive organs
- Urinary Bladder
The image below shows the abdominopelvic cavity:
Serous membrane2: This is a type of thin membrane that lines the various cavities as well as organs inside human body. Made of mesothelium tissue, this membrane is known for providing various vital organs the ability to move without friction.
Anterior3: Positioned at or towards the front.
Posterior4: Positioned at or towards the back.
Pelvis5: Pelvis refers to either of the two:
- It is the lower part of the human body torso (sometimes referred to as trunk) located between thighs and the abdomen. It is known as the pelvic region.
- It is the skeleton embedded in pelvic region or the lower part of the human body torso between thighs and the abdomen. It is known as pelvic skeleton or bony pelvis.
Constrictions6: These refer to the physiologic narrowings of the ureter. In other words, these are the places where the ureter becomes narrow.
Bifurcation7: It refers to division of something into two branches or parts.