Final answer:
The primary function of stomach mucus is to protect stomach cells from autodigestion by forming a physical barrier and neutralizing acid.
Step-by-step explanation:
The primary function of the mucus in the stomach is to protect stomach cells from autodigestion.
The stomach lining is exposed to the highly corrosive acidity of gastric juice, which can digest the stomach itself. However, the mucosal barrier in the stomach protects the underlying tissue from the action of the digestive juices. The stomach wall is covered by a thick coating of bicarbonate-rich mucus, which forms a physical barrier and neutralizes acid. Additionally, the epithelial cells of the stomach's mucosa meet at tight junctions, blocking gastric juice from penetrating the underlying tissue layers. The surface epithelium of the stomach is completely replaced every 3 to 6 days to quickly replace damaged epithelial mucosal cells.