Gastric epithelium is liable to be attcked by acid
and gastric enzymes but it is protected by a thick alkaline mucus
that is secreted by the surface epithelium.
protective barrier between the epithelium and the
acid and pepsin in the gastric lumen
mucus is heavily glycosylated to protect it from proteolysis
mucus layer is also buffered by HCO3 secreted by the
epithelial cells that produces a protective pH gradient across the