Urotheliális

Urotheliális refers to a specific type of tissue found in the urinary tract. This specialized epithelium, also known as transitional epithelium, lines the renal pelvis, ureters, bladder, and the proximal part of the urethra in both males and females. The most distinguishing feature of urothelium is its ability to undergo significant changes in shape and volume. When the bladder is empty, the urothelial cells are typically stratified and rounded, appearing somewhat plump. However, as the bladder fills with urine, these cells flatten and stretch, allowing the bladder to expand considerably without damaging the underlying tissue. This remarkable plasticity is facilitated by the unique structure of the urothelial cells, particularly the presence of umbrella cells which are large, superficial cells that can cover many underlying cells. The apical surface of these umbrella cells contains specialized plaques that are thought to play a role in maintaining the impermeability of the urothelium, preventing the diffusion of urine into the surrounding tissues. Urothelium also serves as a protective barrier against the potentially harmful components of urine. Abnormalities in urothelial tissue can lead to various medical conditions, including urothelial carcinoma, a type of cancer that originates in the cells of the urothelium.