The body’s line of defense against HCl:
The esophagus, stomach, and small intestine each have their own mechanisms for protection against the dangerously low pH of stomach acid, whether keeping acid away from sensitive tissues or neutralizing acid already present.
*Peristalsis clears the esophagus by pushing stomach contents back into the stomach; gravity also aids this process.
Saliva naturally contains bicarbonate, a chemical that helps to neutralize acid in the digestive tract.
Layers of cells called *stratified squamous epithelium line the esophagus and keep acid from seeping in deep enough to do serious damage.
Mucous glands in the wall of the esophagus secrete a protective lubricant.