Umbrella cells are found in which epithelium?

• A. Transitional epithelium
• B. Simple squamous
• C. Cardiac muscle
• D. Loose connective tissue

Answer: (A)

Umbrella cells are the large, dome-shaped superficial cells of the urothelium, the specialized transitional epithelium that lines the urinary tract (urinary bladder, ureters, renal pelvis, and part of the urethra). This epithelium is designed to stretch as the bladder fills, and umbrella cells form a protective, highly impermeable barrier at the luminal surface. They have a distinctive apical membrane with uroplakin plaques that help prevent urine from penetrating the tissue. Their shape and behavior reflect the need for an adaptable, stretchable surface, which is why transitional epithelium is the right context. They aren’t features of simple squamous epithelium, cardiac muscle, or loose connective tissue, which represent different tissue types altogether.