Parietal cells

Parietal cells are specialized secretory cells located in the gastric glands of the stomach that produce hydrochloric acid (HCl). The HCl they secrete creates an extremely acidic environment essential for protein digestion, pathogen destruction, and activation of digestive enzymes like pepsin. Intrinsic factor, also secreted by parietal cells, is crucial for vitamin B12 absorption in the ileum. These cells are characterized by abundant mitochondria and an extensive intracellular canalicular system that expands during acid secretion.