The answer is found in the makeup of the stomach’s digestive juices and its protective lining. These two chemical compounds are both ideally suited for their opposing tasks.
The digestive juices in the stomach consist mainly of hydrochloric acid (HCI), a strongly acidic solution as you saw on the PH Scale. This stuff can dissolve some metals!
The stomach wall is made up mostly of protein, left unprotected the acid would eat right through it. Fortunately for us, the stomach walls have a lining that contains epithelial cells that secrete a protective layer of mucus and bicarbonate.
The mucous is pretty much the same stuff which lines our throat and nose. It sticks to the walls of the stomach to provide a physical barrier so the acid doesn’t touch the stomach itself.
When the cells come into contact with acid, they secrete bicarbonate. Bicarbonate is highly alkaline and very effective at neutralizing acid. This combination of mucous and bicarb is so good at doing its job that when the stomach’s acidity level is high, like PH 2, the stomach lining PH is around 7, or neutral.
Another fact that tells us how incredible our bodies are. Treat your body well, you have to live the rest of this life in it!