Stregth of the Gastric Acid?

How does the stomach withstand the strength of the gastric acid?

Because gastric acid is so strong, the stomach has to have a defense mechanism to keep it from eating itself. This defense mechanism is in the form of a constant production of bicarbonate, which coats the layer of the stomach known as the mucosa. Bicarbonate is a base, and helps to neutralize the acid that touches the mucosa, keeping it contained within.