Which gastric gland cells secrete acid and pepsinogen, respectively?

• A. Parietal cells secrete mucus; Chief cells secrete acid.
• B. Parietal cells secrete pepsinogen; Chief cells secrete bicarbonate.
• C. Parietal cells secrete acid; Chief cells secrete pepsinogen.
• D. Parietal cells secrete hormones; Chief cells secrete water.

Answer: (C)

Acid production in the stomach is carried out by parietal cells, which secrete hydrochloric acid into the lumen (and also intrinsic factor). Pepsinogen, the inactive precursor to the digestive enzyme pepsin, is produced by chief cells in the gastric glands. When pepsinogen encounters the acidic environment created by the parietal cells, it is activated to pepsin and begins protein digestion. So the combination of acid and pepsinogen comes from parietal cells and chief cells, respectively. Mucus-secreting cells provide a protective mucous layer, bicarbonate secretion is associated with that mucous barrier, and enteroendocrine cells secrete hormones—these are not the primary secretions in this pairing.