Mastering Medical
USMLE Step 1 · Embryology & Anatomy

Chief and parietal cells vs G cells and mucous cells

How to tell Chief and parietal cells and G cells and mucous cells apart when a board question makes them look alike.

Fastest separator

Chief is pepsinogen; parietal is acid/intrinsic factor; G cell is gastrin; mucous cell is protective mucus/bicarbonate.

Side by side

Chief and parietal cellsG cells and mucous cells
Key clue

Chief cells secrete pepsinogen; parietal cells secrete hydrochloric acid and intrinsic factor in the gastric body/fundus.

G cells secrete gastrin from antrum; mucous cells secrete bicarbonate-rich mucus for gastric epithelial protection.

Mechanism

Chief cells secrete pepsinogen; parietal cells secrete hydrochloric acid and intrinsic factor in the gastric body/fundus.

G cells secrete gastrin from antrum; mucous cells secrete bicarbonate-rich mucus for gastric epithelial protection.

The repair move

Before naming the answer, force the stem through the separator: Chief is pepsinogen; parietal is acid/intrinsic factor; G cell is gastrin; mucous cell is protective mucus/bicarbonate.

Try a free question

Core

A gastric body biopsy shows cells with eosinophilic cytoplasm and abundant mitochondria; these cells contain canaliculi with H+/K+ ATPase pumps and secrete hydrochloric acid into the gastric lumen. They also secrete intrinsic factor for vitamin B12 absorption. Which cell type is this?

Show answer and explanation

Answer: A. Parietal cells. Parietal cells in the gastric body and fundus secrete hydrochloric acid (via H+/K+ ATPase pumps on canalicular membranes) and intrinsic factor (essential for vitamin B12 absorption in the terminal ileum). Parietal cells are stimulated by acetylcholine (M3), gastrin (CCK-B), and histamine (H2 receptors, the target of H2 blockers and indirectly of PPIs).

Why the other choices are tempting

  • B. Chief cells secrete pepsinogen (which is converted to active pepsin in the acidic gastric lumen).
  • C. G cells in the antrum secrete gastrin to stimulate acid secretion.
  • D. Mucous neck cells secrete bicarbonate-rich mucus for epithelial protection.
  • E. ECL cells in the body/fundus secrete histamine that stimulates parietal cells.

Flashcards

Tap a card to flip it.

What clue supports Chief and parietal cells?

Choose Chief and parietal cells when the stem gives this pattern: Chief cells secrete pepsinogen; parietal cells secrete hydrochloric acid and intrinsic factor in the gastric body/fundus.

What clue supports G cells and mucous cells?

Choose G cells and mucous cells when the stem gives this contrasting pattern: G cells secrete gastrin from antrum; mucous cells secrete bicarbonate-rich mucus for gastric epithelial protection.

Quick answers

What is the fastest way to tell Chief and parietal cells from G cells and mucous cells?

Chief is pepsinogen; parietal is acid/intrinsic factor; G cell is gastrin; mucous cell is protective mucus/bicarbonate.

What is the key clue for Chief and parietal cells?

Chief cells secrete pepsinogen; parietal cells secrete hydrochloric acid and intrinsic factor in the gastric body/fundus.

What is the key clue for G cells and mucous cells?

G cells secrete gastrin from antrum; mucous cells secrete bicarbonate-rich mucus for gastric epithelial protection.