Goblet cells are specialized mucus-secreting cells found in which epithelia?

• A. Respiratory and intestinal epithelia
• B. Skin epidermis
• C. Kidney tubule
• D. Ducts of salivary glands

Answer: (A)

Goblet cells are mucus-secreting unicellular glands embedded in mucous epithelia. They’re especially abundant in the respiratory and intestinal linings, where they release mucins that hydrate to form a protective, lubricating mucus layer. In the airways, this mucus traps dust and microbes and works with cilia to clear them away. In the gut, mucus guards the epithelium from digestive enzymes and mechanical stress and helps lubricate the passage of contents. They aren’t a feature of the skin epidermis, which is a dry, keratinized surface, nor are they typical in kidney tubules. Ducts of salivary glands rely on mucous and serous secretions from acini rather than goblet cells.