THORAX ABDOMEN AND PELVIS

Detailed explanation-1: -In the stomach several mucosal defence mechanisms protect the stomach against hydrochloric acid and noxious agents. The pre-epithelial protection is made up by the mucus-bicarbonate barrier. Mucus and bicarbonate, secreted by mucus cells, create a pH gradient maintaining the epithelial cell surface at near neutral pH.

Detailed explanation-2: -Gastric mucus is a gel-mucous barrier secreted by epithelial cells and glandular cells in the stomach wall. It acts as part of a barrier that protects the stomach wall from the acid and digestive enzymes within the stomach lumen.

Detailed explanation-3: -Secretion of bicarbonate into the adherent layer of mucus gel creates a pH gradient with a near-neutral pH at the epithelial surfaces in stomach and duodenum, providing the first line of mucosal protection against luminal acid.

Detailed explanation-4: -The mucus protects the inner lining of the stomach from the secretion of the HCl. Hydrochloric acid (HCl), which is a strong acid that kills bacteria present in the food material. The mucus present in the gastric juice plays an important role in lubrication and protection of the mucosal epithelium.