Where can transitional epithelium be found?

Transitional epithelium is specifically designed to accommodate fluctuations in the volume of the organ it lines, which is most commonly the urinary system. This type of epithelium is unique in its ability to stretch and contract, allowing it to line structures that fill and empty, such as the bladder. In its relaxed state, transitional epithelium appears plump and multilayered, providing a robust barrier to prevent urine from seeping back into the underlying tissues. When the bladder fills, the epithelial cells become more flattened, demonstrating the tissue's extraordinary flexibility.

The other options do not contain transitional epithelium. The respiratory tract is lined with ciliated pseudostratified columnar epithelium, which helps with the movement of mucus and particles. The mouth and esophagus mainly feature stratified squamous epithelium, providing protection against abrasion. Glandular tissues are typically covered with various types of simple or stratified epithelium, but not transitional epithelium. Thus, the urinary system is the correct context for transitional epithelium, highlighting its specialized role in accommodating changes in volume.