Which epithelium lines the urinary bladder?

Which epithelium lines the urinary bladder?

• A. Stratified squamous epithelium
• B. Simple squamous epithelium
• C. Simple cuboidal epithelium
• D. Transitional epithelium

Answer: (D)

The lining of the urinary bladder is transitional epithelium (urothelium) because it can stretch to accommodate varying urine volumes while still forming a strong, waterproof barrier. This tissue has a layered, elastic structure with dome-shaped surface cells when relaxed that flatten as the bladder fills. This adaptability protects underlying tissues from urine and prevents leakage during expansion. Other epithelial types aren’t suited for these needs: stratified squamous protects against abrasion but is not as stretchable; simple squamous is too thin for a robust barrier and lines vessels and body cavities; simple cuboidal lines many glands and kidney tubules, not the bladder.

The lining of the urinary bladder is transitional epithelium (urothelium) because it can stretch to accommodate varying urine volumes while still forming a strong, waterproof barrier. This tissue has a layered, elastic structure with dome-shaped surface cells when relaxed that flatten as the bladder fills. This adaptability protects underlying tissues from urine and prevents leakage during expansion. Other epithelial types aren’t suited for these needs: stratified squamous protects against abrasion but is not as stretchable; simple squamous is too thin for a robust barrier and lines vessels and body cavities; simple cuboidal lines many glands and kidney tubules, not the bladder.