How do the mucosa of the stomach differ from that of the small intestine in terms of secretion and absorption?

• A. Stomach mucosa has gastric glands with parietal, chief, and mucus cells for secretion; small-intestine mucosa has villi/microvilli with absorptive enterocytes and brush-border enzymes for absorption.
• B. Stomach mucosa contains only mucus-secreting cells; small-intestine mucosa has no goblet cells.
• C. Stomach mucosa secretes bile; small-intestine mucosa secretes mucus only.
• D. Stomach mucosa and small-intestine mucosa have identical secretions and absorptions.

Answer: (A)

Structure dictates function here. The stomach mucosa is organized around gastric glands that include parietal cells, chief cells, and mucus-secreting cells. Parietal cells produce hydrochloric acid and intrinsic factor, chief cells release pepsinogen, and mucus cells secrete protective mucus. This combination creates gastric juice for protein digestion and lining protection, with only limited absorption occurring in the stomach.

In contrast, the small intestine mucosa is designed for maximal absorption. It features villi and microvilli that dramatically increase surface area, with absorptive enterocytes on the surface paired with brush-border enzymes to finish digestion at the luminal surface. This setup enables efficient uptake of nutrients like sugars, amino acids, and fats. Goblet cells also secrete mucus to protect and lubricate, but the primary distinction is the extensive surface area and enzymatic machinery geared toward absorption.

Bile is produced by the liver, not the stomach, and the small intestine does not lack goblet cells, so those statements don’t fit the actual anatomy and function.