Final answer:
The mucosal barrier of the stomach is protected by mucus secretion, bicarbonate secretion, and tight junctions between epithelial cells, which prevent self-digestion and damage from acidic gastric juices.
Step-by-step explanation:
The three factors that create the mucosal barrier to protect the stomach are: 1) Mucus secretion, 2) Bicarbonate secretion, and 3) Tight junctions between epithelial cells.
Mucus secretion by the stomach's epithelial lining involves the release of a protective coat of alkaline mucus. This mucus forms a physical barrier that shields the underlying tissue from acidic gastric juices. Bicarbonate secretion within the mucus neutralizes the stomach acid, helping to maintain a stable pH environment.
The tight junctions between the epithelial cells are crucial as they prevent gastric acid and other digestive enzymes from reaching the delicate tissues beneath the mucosa. Collectively, these protective factors are essential for preventing self-digestion of the stomach lining.