(redirected from Ureters)
Also found in: Dictionary, Thesaurus, Medical, Wikipedia.


(yo͝orē`tər), thick-walled tube that conveys urine from the kidneykidney, artificial,
mechanical device capable of assuming the functions ordinarily performed by the kidneys. In treating cases of kidney failure a tube is inserted into an artery in the patient's arm and blood is channeled through semipermeable tubes immersed in a bath
..... Click the link for more information.
 to the urinary bladder. It is approximately 10 in. (25.4 cm) long, with the upper half located in the abdomen and the lower half in the pelvic region. Urine is transported down this tube under the impetus of gravity assisted by contractions of the smooth muscles that line the ureteral walls. A blocked ureter can result from congenital abnormality, a tumor, or the formation of kidney stones. Blockage may require surgery to prevent loss of urinary function and eventual urea poisoning. See urinary systemurinary system,
group of organs of the body concerned with excretion of urine, that is, water and the waste products of metabolism. In humans, the kidneys are two small organs situated near the vertebral column at the small of the back, the left lying somewhat higher than the
..... Click the link for more information.
The Columbia Electronic Encyclopedia™ Copyright © 2013, Columbia University Press. Licensed from Columbia University Press. All rights reserved. www.cc.columbia.edu/cu/cup/
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.



the efferent duct that serves to remove the urine from the kidney.

During the embryonic development of many vertebrates, the excretory function is fulfilled by three successive forms of kidney: the pronephros (also called the primordial kidney or the forekidney), the mesonephros (also called the middle kidney), and the metanephros—the definitive, permanent kidney. Correspondingly, three types of ureter arise: the pronephric duct, the mesonephric duct (also called Wolffian duct), and the metanephric duct—the definitive, permanent ureter.

The pronephric ducts continue to function past the embryonic stage only in cyclostomes, in which the ducts open into the urogenital sinus. In fish and amphibians, the Wolffian ducts continue to function as ureters throughout postembryonic life. In certain fish—dipnoans, chondrosteans, and holosteans—and in male amphibians, the ureters also function as the deferent ducts. The mesonephric ducts of fish open to the exterior of the body either directly through the urinary orifice (in all female teleosts and in the males of a few teleost species), through the urogenital sinus (in elasmobranchs, holocephalans, chondrosteans, holosteans, Polypterus, and most male teleosts), or through the cloaca (in chondrichthians and dipnoans). In most teleosts, the ureters empty into the urinary bladder. The metanephric ducts are the postembryonic ureters of reptiles, birds, mammals, and man; in all these, the sole function of the ureter is to conduct urine. In birds, monotremes, and most reptiles, the ureters empty into the cloaca, while in metatherians, viviparous mammals, certain reptiles, and man, they empty into the urinary bladder.

In man the two ureters are tubular organs through which urine flows from the kidneys into the urinary bladder. The ureters are situated on the posterior wall of the abdominal cavity on both sides of the spinal column. On the average, each ureter is 30–35 cm long and 7–9 mm at its widest diameter. The ureters are internally lined with mucosa. Smooth muscles in the walls of the ureters ensure the flow of urine to the urinary bladder, regardless of the position the body is in.

Urethritis—inflammation of the ureteral mucosa—is the commonest disease of the ureters. Kidney stones can pass through the ureters, causing injury to the ureteral linings. Occasionally, one or both ureters can be congenitally bifurcated at the site of emergence from the kidney; complete doubling of one or both ureters is also possible. Other developmental anomalies include prolapse of the ureter into the vagina (in women) or into the seminal vesicles (in men).

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.


A long tube conveying urine from the renal pelvis to the urinary bladder or cloaca in vertebrates.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.


the tube that conveys urine from the kidney to the urinary bladder or cloaca
Collins Discovery Encyclopedia, 1st edition © HarperCollins Publishers 2005
References in periodicals archive ?
La ectopia ureteral es la desembocadura de uno o ambos ureteres en una ubicacion distinta al trigono vesical [3], siendo los lugares mas comunes vagina (70%), uretra (12%), cuello de la vejiga (8%) y utero (3%) [1, 2, 8]; el peor pronostico es para la ectopia que desemboca en la uretra, ya que se asocia a un alto porcentaje de incontinencia postquirurgica [6].
The luminal flow rates in the three different ureters with a double J stent without side holes showed similar patterns (Figure 3).
In the 15 minutes film (Figure 1), we see the normal opacification of both PCS and normal course of both ureters in their whole extent, but in the 45 minutes film (Figure 2 and 3) we see left duplicated system with bifid blind-ending left distal ureter, which is dilated and tortuous suggestive of either due to uretero-ureteral reflux or vesicoureteric reflux.
Primary small cell carcinoma of the ureter. Can J Urol.
Due to the shortage of organ donors, the use of marginal donors including donors with ureteropelvic junction obstruction (UPJO) is becoming more prevalent.[sup][1] An anastomosis of allograft pelvis to native ureter has been reported to be a treatment for donor kidney with UPJO at initial transplantation;[sup][2] however, few studies focused on the surgical option for urinary tract reconstruction of donor kidney with UPJO in re-transplantation.
A right ureteral stone was suspected in kidney, ureter, and bladder urography and a noncontrast computed tomography revealed a 1 cm right distal ureteral stone and a millimetric calculi in middle pole of left kidney.
Intravenous pyelography has vital role not only clearly demonstrating duplex pelvi-calyceal system and ureters but also clearly documenting the sparing of upper pole moiety parenchyma and pelvi-calyceal system as well as pelvi-calyceal system of lower moiety as compared to CT scan because of large tumor overlap with renal parenchyma on CT scan.
The condition is usually due to an increased aneurysm diameter obstructing the ureter mechanically (3).
The primary retroperitoneal organs are the adrenal glands, kidneys, ureter, the abdominal aorta, inferior vena cava and their branches.
Out of 151 cases of successfully accessed ureters, 81.5% (123/151) were undertaken for mid and lower ureteric calculi and 18.5% (28/151) for upper ureteric calculi.
CT urogram without contrast demonstrated wall thickening with circumferential calcification of the middle left ureter with mild luminal narrowing without hydronephrosis.
On April 28, 2009, a urologist placed a stent in the right ureter but was unable to place a stent in the left ureter.