The ureter (cross-section, longitudinal section) transports urine from the kidney to the urinary bladder.

The ureters are fibromuscular tubes that transfer urine from the kidney to the bladder via peristalsis. Similar to the bladder, it is lined with transitional epithelium (urothelium).

• Urothelium (transitional epithelium) (cross-section, longitudinal section) – lines the interior of the ureter and
is impermeable to water and ions.

• Three to ten layers of cells.

• Umbrella Cells – the top layer of cells which changes in size and shape depending on the distention of the
ureter. (Some cells are binucleate.)

• Lamina Propria (cross-section, longitudinal section) – dense fibro-elastic connective tissue that supports the
urothelium.

• Muscularis Propria (muscularis externa) (cross-section, longitudinal section) – contractions pump urine from
the kidney to the urinary bladder.

• Described as two layers (inner longitudinal and outer circular) in the proximal ureter or three layers (inner
longitudinal, middle circular, and outer longitudinal) as the ureter approaches the bladder. Elsewhere the
orientation of the muscle may be less clear.

• These layers may be interlaced and not orthogonal reflecting the spiral orientation of some of the smooth
muscle.

• Adventitia (cross-section, longitudinal section) – ureter is covered with loose connective tissue, fat, blood
vessels, and nerves.

SLIDE NAME: MHS 215 Ureter
TISSUE: Ureter (cross and longitudinal sections)
STAIN: Hematoxylin & Eosin
MAGNIFICATION: 40x
SOURCE: Robert L. Sorenson
University of Minnesota
Minneapolis, MN