A pair of narrow tubes, about 25 cm long, running behind the peritoneum from the renal pelvis to the pelvis proper
Ureters — the urine-carrying tubes.
Anatomy · Organs & viscera
Ureter
About 25 cm long, 3 mm wide
Abdomen and pelvis · urinary system
The ureters are a pair of narrow muscular tubes, each about 25 cm long, that carry urine from the renal pelvis of each kidney down to the bladder. They run down behind the peritoneum on the surface of psoas major, cross the pelvic brim over the iliac vessels and pass obliquely through the bladder wall. They have three natural narrowings where kidney stones tend to lodge.
How to spot them
- ▸A thin, thick-walled tube about 3 mm across running from the renal pelvis to the bladder, behind the peritoneum
- ▸Descends on the front of psoas major, crossing the pelvic brim near the bifurcation of the common iliac artery
- ▸Three constrictions: the pelviureteric junction, the pelvic brim, and where it enters the bladder wall
- ▸In the pelvis it passes beneath the uterine artery (female) or the vas deferens (male)
What to know
Three points of natural narrowing where stones commonly lodge: at its top, at the brim of the pelvis and where it enters the bladder
The three constrictions of the ureter.
Crosses in front of the common iliac artery bifurcation at the pelvic brim, after running down the front of psoas major
The ureter at the pelvic brim.
A tube that runs beneath the uterine artery in the broad ligament — 'water under the bridge'
The ureter, at risk during a hysterectomy when the uterine artery is tied.
In men it passes beneath the vas deferens just before it reaches the bladder
The ureter and the vas deferens — 'water under the bridge' in men as well.
Pain that comes in waves and radiates from the loin to the groin as a stone passes
Ureteric colic — a stone in the ureter.
Runs obliquely through the wall of the bladder, forming a flap valve that stops urine flowing back up
The intramural ureter at the vesicoureteric junction.
Key ideas
- Waves of peristalsis, about one to five a minute, push urine from the kidney to the bladder.
- The oblique tunnel through the bladder wall acts as a valve; when the bladder fills, the tunnel is compressed and closed.
Quick-fire facts
- •Each ureter is about 25 to 30 cm long and about 3 mm wide, wider at the two narrowings.
- •Its wall has an inner mucosa of urothelium (transitional epithelium), a muscular layer and an outer adventitia.
- •The ureter is crossed in front by the gonadal (testicular or ovarian) vessels on its way down.
- •In the female pelvis it lies close to the cervix, about 2 cm from it, and passes beneath the uterine artery.
- •Blood is supplied by branches of the renal, gonadal, common iliac, internal iliac and vesical arteries.
- •Each ureter enters the bladder at an oblique angle at the upper corners of the trigone.
- •A stone smaller than about 5 mm usually passes by itself.
- •The right ureter lies alongside the inferior vena cava; the left lies close to the aorta.
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