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How does bicarbonate from the pancreas protect the small intestine from stomach acid?

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Diagram of the human digestive system viewed from the front, showing and labeling organs including the mouth, teeth, tongue, salivary glands, pharynx, esophagus, liver, stomach, gallbladder, pancreas, large intestine, small intestine, appendix, rectum, and anus. — digestion The human digestive system as seen from the front.

When acidic chyme—a mixture of food and gastric secretions—enters the duodenum from the stomach, it triggers the release of the hormone secretin into the bloodstream.12

Secretin acts as a chemical messenger that stimulates the duct cells of the pancreas to secrete water and bicarbonate. These pancreatic secretions travel through ducts into the descending duodenum, where the bicarbonate promptly neutralizes the hydrochloric acid present in the gastric mixture. By diluting and neutralizing this acid, the pancreas protects the delicate mucosal lining of the small intestine from potential damage.132