Ureter
Gray's	subject #254 1225
Artery	Superior vesical artery, Vaginal artery, Ureteral branches of renal artery
Precursor	Ureteric bud
MeSH	Ureter
Dorlands/Elsevier	Ureter

In human anatomy, the ureters are muscular tubes that propel urine from the kidneys to the urinary bladder. In the adult, the ureters are usually 25–30 cm (10–12 in) long and ~3-4 mm in diameter.

In humans, the ureters arise from the renal pelvis on the medial aspect of each kidney before descending towards the bladder on the front of the psoas major muscle. The ureters cross the pelvic brim near the bifurcation of the iliac arteries (which they run over). This "pelviureteric junction" is a common site for the impaction of kidney stones (the other being the ureterovesical valve). The ureters run posteroinferiorly on the lateral walls of the pelvis They then curve anteriormedially to enter the bladder through the back, at the vesicoureteric junction, running within the wall of the bladder for a few centimeters. The backflow of urine is prevented by valves known as ureterovesical valves.

In the female, the ureters pass through the mesometrium on the way to the urinary bladder.

Ureters are also found in all other amniote species, although different ducts fulfil the same role in amphibians and fish.^[1]

Contents 1 Histology 2 References 3 External links 4 Additional images

[edit] Histology

The ureteric lumen is star-shaped. Like the bladder, it is lined with transitional epithelium, and contains layers of smooth muscle, thereby being under autonomic control.

The epithelial cells of the ureter are stratified (in many layers), are normally round in shape but become squamous (flat) when stretched. The lamina propria is thick and elastic (as it is important that it is impermeable).

There are two spiral layers of smooth muscle in the ureter wall, an inner loose spiral, and an outer tight spiral. The inner loose spiral is sometimes described as longitudinal, and the outer as circular, (this is the opposite to the situation in the gastrointestinal tract). The distal third of the ureter contains another layer of outer longitudinal muscle.

The adventitia of the ureter, like elsewhere is composed of fibrous connective tissue, that binds it to adjacent tissues.

[edit] References

[edit] External links

• SUNY Labs 40:06-0111 - "Posterior Abdominal Wall: Internal Structure of a Kidney"
• SUNY Figs 43:08-02 - "Relationship of the ureter to the uterine artery."
• SUNY Figs 44:02-01 - "Mid-sagittal section of male pelvis."
• SUNY Anatomy Image 8923
• SUNY Anatomy Image 8945
• Virtual Slidebox at Univ. Iowa Slide 444
• Organology at UC Davis Urinary/mammal/ureter/ureter1 - "Mammal, ureter (LM, Medium)"
• Histology at KUMC urinary-renal15 - "Ureter"
• Cross section at UV pelvis/pelvis-female-17

[edit] Additional images

Bladder

Frontal section through the kidney

Wall of the ureter.

Transverse section of human embryo eight and a half to nine weeks old.

Tail end of human embryo thirty-two to thirty-three days old.

The relations of the viscera and large vessels of the abdomen. (Seen from behind, the last thoracic vertebra being well raised.)

The posterior surfaces of the kidneys, showing areas of relation to the parietes.

Vertical section of kidney.

Transverse section of ureter.

The interior of bladder.

Fundus of the bladder with the vesiculæ seminales.

Median sagittal section of male pelvis.

Microscopic view of dog ureter.

v • d • e Anatomy: urinary system (TA A08, GA 11.1215) Abdomen Kidneys Layers Renal fascia • Renal capsule • Renal cortex  (Renal column) • Renal medulla (Renal sinus, Renal pyramids, medullary interstitium) • Renal lobe • Cortical lobule • Medullary ray • Nephron Afferent circulation Renal artery → Segmental arteries → Interlobar arteries → Arcuate arteries → Interlobular arteries → Afferent arterioles → Renal corpuscle (Glomerulus, Bowman's capsule) Renal tubule Proximal tubule → Loop of Henle (Descending, Thin ascending, Thick ascending) → Distal convoluted tubule → Connecting tubule → Collecting ducts aka Duct of Belini → Renal papilla → Minor calyx → Major calyx → Renal pelvis Efferent circulation Glomerulus → Efferent arterioles → Peritubular capillaries / Vasa recta → Arcuate vein → Interlobar veins → Renal vein Juxtaglomerular apparatus Macula densa • Juxtaglomerular cells • Mesangium/Extraglomerular mesangial cell Filtration Glomerular basement membrane • Podocyte • Filtration slits • Mesangium/Intraglomerular mesangial cell • Tubular fluid Ureters Orifice of ureter Pelvis Bladder Uvula • Trigone • Detrusor • Apex • Neck Urethra Urethral sphincters (External sphincter muscle of male urethra, External sphincter muscle of female urethra, Internal sphincter muscle of urethra) urinary system navs: anat/physio/dev, noncongen/acid+base/congen/neoplasia, symptoms+signs/eponymous, proc