Learn what the stomach produces so that it doesn't digest itself.
The stomach is essentially a bag made of strong muscle tissue lying between the esophagus and the duodenum (or, in simpler terms, the throat and the intestines) which serves both to store the food we eat and to prepare it for digestion in the intestinal system.
Without the stomach, we would need to eat every 20 minutes or so as opposed to taking regular meals.
Mucus is essential to the digestion process because of the toxic acids the stomach produces to break down food.
The stomach secretes a potent mix of gastric juices to begin the breakdown of the ingested food, including an enzyme called pepsin, which breaks down protein. The stomach also produces hydrochloric acid.
The enzyme pepsin is secreted as pepsinogen, which is inactive until it mixes with the hydrochloric acid. About 2-3 litres of gastric fluids are released into the stomach daily, so the stomach wall secretes protective mucus to prevent the stomach from digesting itself.
The most common of the epithelial cells forming the stomach wall are mucous cells in fact.
Even so, 500,000 epithelial cells of the surface lining are shed every minute, thereby protecting the deeper layers of the stomach wall. This surface layer is replaced completely every three days and the entire lining regenerates itself every two weeks.