Which region of the GI tract contains the highest density of goblet cells, and what is their function?

• A. Stomach
• B. Small intestine
• C. Colon
• D. Esophagus

Answer: (C)

Goblet cells are mucus-secreting cells in the lining of the GI tract. Their main job is to produce mucins that hydrate into mucus, which lubricates the contents and protects the epithelium from mechanical damage and bacterial irritation.

The colon has the highest density of goblet cells because it needs a thick mucus layer to lubricate the passage of feces and to shield the mucosa during water reabsorption and stool formation. This mucus barrier also helps keep bacteria from reaching the epithelium.

In other regions, goblet cells are present but not as plentiful: the esophagus is lined by stratified squamous epithelium and lacks goblet cells; the stomach relies on surface mucus cells for its protective layer; and the small intestine has goblet cells too, but in fewer numbers than the colon.