What is the dome-shaped cell at the surface of transitional epithelium commonly called?

What is the dome-shaped cell at the surface of transitional epithelium commonly called?

• A. Umbrella cell
• B. Basal cell
• C. Squamous cell
• D. Columnar cell

Answer: (A)

The surface layer of transitional epithelium is made up of large, dome-shaped cells known as umbrella cells. These superficial cells sit on top of the deeper layers and are specialized to form a tight, protective barrier that can stretch as the urinary tract fills. Their large size and unique apical membrane, reinforced by uroplakin plaques, help keep urine out of the underlying tissue while allowing the epithelium to expand. The other cell types—basal, squamous, or columnar—refer to different layers or epithelia and do not describe the dome-shaped surface cells of the urothelium.

The surface layer of transitional epithelium is made up of large, dome-shaped cells known as umbrella cells. These superficial cells sit on top of the deeper layers and are specialized to form a tight, protective barrier that can stretch as the urinary tract fills. Their large size and unique apical membrane, reinforced by uroplakin plaques, help keep urine out of the underlying tissue while allowing the epithelium to expand. The other cell types—basal, squamous, or columnar—refer to different layers or epithelia and do not describe the dome-shaped surface cells of the urothelium.