Why doesn't hydrochloric acid destroy the stomach lining?

Hydrochloric acid does not destroy the stomach lining because of the protective mucus layer that coats the stomach's internal surface. This mucus is secreted by specialized cells and serves as a barrier, preventing the acid from damaging the stomach tissue. The mucus not only neutralizes the acidity to some extent but also provides a physical barrier that shields the underlying cells from the harsh environment created by the acid.

In addition, the stomach lining has a high turnover rate, with cells regenerating rapidly, but this is a secondary factor in protecting the stomach from damage. While hormones play a role in the digestive process, they do not specifically neutralize hydrochloric acid. Additionally, the thickness of the stomach lining is not the primary reason for resistance against acid damage; rather, it is the mucus layer that is crucial in maintaining the integrity of the stomach lining.