What is the function of transitional epithelial cells?

Transitional epithelial cells play a vital role in the urinary system, specifically in organs like the bladder, ureters, and parts of the urethra. Their primary function is to accommodate the stretching and changes in shape that occur as these organs fill and empty with urine. Unlike other types of epithelial cells, transitional cells have a unique ability to stretch and flatten when the bladder is full, and then revert to a more cuboidal shape when it is empty. This dynamic capability enables the bladder to hold varying volumes of urine without tearing or losing integrity, which is crucial for maintaining proper urinary function and protecting underlying tissues.

For this reason, while transitional epithelial cells may also provide some level of protection and contribute minimally to absorption or secretion, their distinctive feature that allows them to stretch and change shape is the defining characteristic that underscores their significance in the urinary system.