Ureter

URETERS

• Ureters are a pair of thick walled tubes which convey urine from kidneys to urinary bladder.
• Lined by transitional epithelium.

• It is a retroperitoneal structure.
• Divided into: i) Abdominal part    ii) Pelvic part.

COURSE:

• The ureter begins within the renal sinus as a funnel shaped dilation, called renal pelvis.
• Ureter emerges from the hilum & runs vertically downward retroperitoneal (behind parietal peritoneum) on the psoas muscle.
• It enters the true (lesser) pelvis by crossing anterior to the bifurcation of common iliac artery & origin of external iliac vessels, in front of sacroiliac (SI) joint.
• Opposite the ischial spine it turns anteromedially to reach the bladder base at an angle (not straight).
• Ureter opens into lateral angle of trigone.
• Ureteric openings lie 5 cm apart in distended bladder & only 2.5 cm apart in empty bladder. 

SITES OF ANATOMICAL NARROWINGS/ CONSTRICTIONS

• The lumen of the ureter isn’t consistent throughout and presents 3 constrictions at these sites:                        

1. At the pelviureteric junction where the renal pelvis joins the upper end of ureter.
   It’s the upper most constriction, seen roughly 5 cm far from the hilum of kidney.
2. At the pelvic brim where it crosses the common iliac artery.
3. At the uretero-vesical junction (i.e., where ureter enters into the bladder).

•   Portions of the ureter between these constrictions reveal spindle shaped dilatations. These constricted parts of the ureter are the sites of arrest of ureteric calculi.
• In addition to above 3 sites of constrictions, 2 more sites of constrictions are described by the surgeons, 1 at juxtaposition of the vas deferens/broad ligament and other at the ureteric orifice.

ABDOMINAL PART

• Important relations of abdominal part:

PELVIC PART

• Relations of pelvic part of ureter are:

• In its forward course, relations are:

 BLOOD SUPPLY:

 NERVE SUPPLY:

• Supplied by sympathetic form T10-L1 segment & parasympathetic from S2-S4 nerves.
• They reach ureter through the renal, aorta & hypogastric plexus.