The primary functions of mucus in the stomach are to lubricate food for movement and to protect the stomach lining from acid and enzymes.
Mucus, a complex secretion produced by specialized cells in the stomach lining (mucous cells), plays a vital role in maintaining gastric health. It accomplishes two key tasks:
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Lubrication: Gastric mucus coats food particles, making them easier to move through the stomach during the churning process of digestion. This facilitates efficient mixing with gastric juices and subsequent passage into the small intestine.
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Protection: Perhaps even more critically, the mucus layer forms a protective barrier between the harsh acidic environment of the stomach and the delicate epithelial cells that line the stomach wall. This barrier prevents the stomach from digesting itself. The mucus layer traps bicarbonate ions, creating a pH gradient. The pH at the surface of the epithelial cells is near neutral (pH 7), while the pH in the stomach lumen can be as low as 1.5 to 2.0. This prevents the acid and pepsin from damaging the stomach lining.
Without this protective mucus layer, the stomach lining would be vulnerable to damage from hydrochloric acid and pepsin (a protein-digesting enzyme) present in gastric juice, potentially leading to ulcers and other complications.
