Abdomen:Hollow viscus:Renal pelves and ureters

The **ureter** is a paired fibromuscular tube that conveys urine from the kidneys in the abdomen to the bladder in the pelvis. The ureter is 25-30cm long and has three parts:

1. **abdominal ureter**: from the renal pelvis to the pelvic brim
2. **pelvic ureter**: from the pelvic brim to the bladder
3. **intravesical**or **intramural ureter:** within the bladder wall

Relations:

Abdominal ureter

* posteriorly: psoas muscle; genitofemoral nerve; common iliac vessels; tips of L2-L5 transverse processes
* anteriorly
	+ right ureter: descending duodenum (D2); gonadal vessels; right colic vessels; ileocolic vessels
	+ left ureter: jejunum, gonadal vessels; left colic vessels; loops of jejunum; sigmoid mesentery and colon
* medially
	+ right ureter: IVC, lumbar lymph nodes,

Constrictions: the ureter has a diameter of 3mm with three constrictions, which are the most common sites of renal calculus obstruction:

* at the pelvi-ureteric junction (PUJ) of the renal pelvis and the ureter
* as the ureter enters the pelvis and cross over the common iliac artery bifurcation
* at the vesicoureteric junction (VUJ) as the ureter enters the bladder wall

Course:

* Passes down on **medial aspect of the psoas** muscle, lying anteriorly to the tips of the L2-L5 transverse processes.
* Crosses over the genitofemoral nerve and below gonadal vessels
* The right ureter lies **behind the D3**, and further down, right colic and ileocolic vessels. the left ureter is lateral to IM vessels and cross below the left colic vessels
* The ureter leaves the psoas muscle at **bifurcation of common iliac artery** over SI joint and into the pelvis, courses **anteriorly to the internal iliac artery** and down the lateral pelvic sidewall.
* Male: at the level of the ischial spine it turns forward and medially to enter the **posterior wall of the bladder,** where it runs an oblique 1-2cm course, before opening into the bladder at the internal ureteric orifice. Crossed by the vas deferens.
* Female: runs in the base of the broad ligament and crossed by the uterine artery.

Blood supply: multiple sources form longitudinal blood channel along the ureter via blood channels.

* Ureteric branch of the renal artery (superior portion)
* Branches of abdoiminal aorta, gonadal, common iliac and internal arteries (middle portion)
* Inferior and superior vesical and uterine arteries (inferior portion)
* Venous drainage is from similarly named veins

Lymph drainage:

* Abdominal portion of the ureter drains into the para-aortic/caval nodes and pelvic portion into the common iliac and internal iliac nodes

Nerve supply:

1. Sympathetic fibres T10-L1 segments via the coeliac and hypogastic plexuses
2. Parasympathetic from the pelvic splanchnic nerves
3. Pain fibres accompany sympathetic nerves similar to the kidneys

Variations

* Duplication caused by low division of ureteric bud. Upper pole inserts lower into the bladder, vagina, or urethra
* Bifid ureter – when duplicated kidneys have separate collecting systems and their ureters unite
* Bifid collecting system – one collecting system for duplicated kidneys
* Double ureter/multiple ureters – from one kidney and they empty into the bladder separately
* Ectopic ureter – empties into an unusual location (lower bladder, urethra, rectum)
* Retrocaval ureter – when right ureter passes behind the IVC
* Ureterocele
* Ureter diverticulum
* Twisted ureter course