MH 146 Ureter

Ureter

Ureter transport urine from the kidney to the bladder. It is lined with an epithelium that is impermeable to water and ions. Peristaltic contraction of the smooth muscle moves urine from the kidney to the bladder.

• Cross-Section - composed of four concentric layers:
  • Transitional Epithelium (Urothelium) - consists of two to three cell layers in the upper ureter with up to ten cell layers near the bladder
    • Umbrella Cells - upper layer of cells that change shape depending on the distention of the ureter (relaxed)
  • Lamina Propria - thick layer of dense irregular connective tissue rich in collagen and elastic fibers
  • Muscularis Externa - irregular arrangement of smooth muscle in two layers (inner longitudinal and outer circular) in the upper ureter or three layers (inner longitudinal, middle circular and outer longitudinal) near the bladder
  • Adventitia - loose connective tissue with blood vessels, nerves and adipose cells

• Longitudinal Section - composed of four concentric layers:
  • Transitional Epithelium (Urothelium) - consists of two to three cell layers in the upper ureter with up to ten cell layers near the bladder
    • Umbrella Cells - upper layer of cells that change shape depending on the distention of the ureter (extended)
  • Lamina Propria - thick layer of dense irregular connective tissue rich in collagen and elastic fibers
  • Muscularis Externa - irregular arrangement of smooth muscle in two layers (inner longitudinal and outer circular) in the upper ureter or three layers (inner longitudinal, middle circular and outer longitudinal) near the bladder
  • Adventitia - loose connective tissue with blood vessels, nerves and adipose cells