PATHOLOGY

Detailed explanation-1: -The hollow portion of the urinary bladder is known as the lumen, and it needs to expand as the bladder fills with urine and contract when a person empties their bladder. Transitional epithelial tissue can expand and stretch, which allows the urinary bladder to expand as it is filled with urine.

Detailed explanation-2: -Transitional epithelium: A transitional epithelium (also known as urothelium) is made up of several layers of cells that become flattened when stretched. It lines most of your urinary tract and allows your bladder to expand.