Which cells in the stomach secrete hydrochloric acid and intrinsic factor?

• A. Chief cells
• B. Mucous cells
• C. G cells
• D. Parietal cells

Answer: (D)

Parietal cells in the stomach are the producers of both hydrochloric acid and intrinsic factor. These cells line the gastric glands of the fundus and body and use a proton pump (H+/K+-ATPase) to secrete hydrogen ions into the lumen, with chloride ions accompanying them, forming hydrochloric acid. This acidic environment lowers the stomach pH, which helps activate pepsinogen to pepsin and aids digestion. Parietal cells also secrete intrinsic factor, a glycoprotein essential for vitamin B12 absorption in the small intestine.

Other gastric cell types have different roles: chief cells secrete pepsinogen, mucous (mucous) cells protect the lining and secrete mucus, and G cells release gastrin which stimulates acid secretion but does not directly secrete acid or intrinsic factor.