What are the types and functions of cells found within the stomach?

The mucosal layer of the stomach contains specialized secretory cells that produce substances that aid in the digestive process. These cells are parietal cells, chief cells, G cells, and mucus cells.

Parietal cells produce hydrochloric acid (gastric acid) that aids in the conversion of the bolus into a chyme. HCl also functions for protein denaturation and activation of protein-digesting enzymes in the stomach. Parietal cells also produce intrinsic factors that help in the transport and absorption of vitamin B12 in the small intestine.

Chief cells produce gastric lipase and pepsinogen. Gastric lipase initially digests lipids into diglycerides. Pepsinogen, on the other hand, is a precursor of pepsin (protein-digesting enzyme) and is activated through contact with HCl.

G cells are endocrine cells that produce the hormone gastrin through vagal stimulation. Gastrin regulates the secretory activities of parietal cells and chief cells.

Mucus cells produce bicarbonate-filled mucus that coats the mucosal layer and protects the stomach from autodigestion by gatsric acids and digestive enzymes.