Name the three main regions of the stomach and identify the primary cell types in each that secrete acid and enzymes.

• A. Antrum contains G cells and mucous cells; Fundus and body contain parietal and chief cells.
• B. Fundus contains mucous cells only; Antrum contains parietal and chief cells.
• C. Fundus and body contain parietal cells (HCl and intrinsic factor) and chief cells (pepsinogen); Antrum contains G cells (gastrin) and mucous cells.
• D. Antrum contains chief cells producing pepsinogen; Fundus and body contain G cells.

Answer: (C)

The stomach is organized so that different regions house specialized secretory cells. In the fundus and body, the main players are parietal cells, which secrete hydrochloric acid to create the acidic environment and intrinsic factor for vitamin B12 absorption, and chief cells, which release pepsinogen that’s activated to pepsin for protein digestion. In the antrum, the key cells are G cells that produce gastrin, a hormone that promotes acid secretion and gastric motility, along with mucous-secreting cells that protect the lining with a mucus barrier.

This pattern matches the description where the fundus and body contain parietal and chief cells (and their products, HCl, intrinsic factor, and pepsinogen), while the antrum contains G cells (gastrin) and mucous cells. The other options misstate which regions house certain cell types or overlook the presence of mucus-secreting cells in the fundus/body, or the role of the antrum.