Goblet cells are typically abundant in which epithelia, and what do they secrete?

• A. In respiratory and intestinal epithelia; mucus (mucins)
• B. In skin; keratin
• C. In brain; neurotransmitters
• D. In liver; bile

Answer: (A)

Goblet cells are specialized mucus-secreting cells that are abundant in mucosal epithelia, especially in the respiratory and intestinal tracts. Their main product is mucus, rich in mucins that hydrate to form a protective, lubricating layer. This mucus traps pathogens and debris in the airways and lubricates the intestinal lining to ease passage of contents. In tissues like skin, keratin forms a tough protective barrier rather than mucus; in the brain, signaling relies on neurotransmitters from neurons; in the liver, bile is produced by hepatocytes. This makes the combination of abundant goblet cells with mucus secretion most characteristic of respiratory and intestinal epithelia.