PATHOLOGY

Detailed explanation-1: -S cells in the small intestine emit secretin. Gastric acid stimulates secretin release, allowing movement into the duodenal lumen. Secretin causes an increase in pancreatic and biliary bicarbonate secretion and a decrease in gastric H+ secretion. Secretin stimulates the secretion of bicarbonate-rich pancreatic fluid.

Detailed explanation-2: -Secretin stimulates the secretion of a bicarbonate-rich pancreatic fluid (45). Secretin enters the blood stream or intestinal lumen and stimulates bicarbonate secretion (by interacting with pancreatic ductal cells), which neutralizes the pH of the gastric chyme upon entering the small intestine (83, 84).

Detailed explanation-3: -This suggests that the first and probably one of the most important role of bicarbonate secretion by pancreatic ductal cells is not only to neutralize the acid chyme entering into the duodenum from the stomach, but to neutralize acidic content secreted by acinar cells.