Q.90.Transitional epithelia is found in which ONE of the following organs?
(A) Liver
(B) Lung
(C) Brain
(D) Urinary bladder

Transitional epithelium lines the urinary bladder, enabling it to stretch during urine storage. The correct answer is (D) Urinary Bladder.​

What is Transitional Epithelium?

Transitional epithelium, also called urothelium, is a stratified epithelial tissue that changes shape from dome-like when relaxed to flat when stretched. This adaptability suits organs with variable volume. It features multiple cell layers, including umbrella cells on the surface that prevent urine leakage.​

Correct Answer: Urinary Bladder

The urinary bladder requires transitional epithelium to expand up to four times its size as it fills with urine, then contract during emptying. This tissue’s elasticity maintains barrier function against urine toxins.​

Why Not Liver?

Liver epithelium consists of simple cuboidal or columnar cells in hepatocytes and bile ducts, focused on metabolism and filtration, not stretching.​

Why Not Lung?

Lungs feature simple squamous epithelium (alveoli) for gas exchange and pseudostratified ciliated columnar in airways for mucus clearance, without stretch needs.​

Why Not Brain?

Brain lacks epithelium lining; it has ependymal cells (cuboidal or columnar) in ventricles for cerebrospinal fluid production, not transitional type.​