The First Discovered Hormone: Secretin

Secretin is the first hormone to be discovered. It was discovered by British physiologist Sir Ernest Starling in 1902. Secretin is a hormone that stimulates the secretion of bicarbonate-rich pancreatic juice. The hormone is produced by S-cells in the duodenum in response to the presence of acidic chyme (partially digested food) in the small intestine.

Function and Mechanism of Secretin

Secretin plays a vital role in the digestive system. It stimulates the secretion of bicarbonate-rich pancreatic juice, which helps neutralize the acidic chyme entering the small intestine from the stomach. This neutralization is essential for the proper functioning of digestive enzymes in the small intestine.

Secretin is released into the bloodstream and carried to the pancreas, where it binds to receptors on the pancreatic duct cells. This binding triggers the release of bicarbonate-rich pancreatic juice into the small intestine.

Importance of Secretin

The discovery of secretin was a significant milestone in the history of endocrinology. It paved the way for the discovery of other hormones that regulate various physiological responses in the body. Secretin also helped scientists understand the complex interplay between the digestive system and the endocrine system.

Conclusion

In conclusion, secretin is the first hormone to be discovered. It plays a vital role in the digestive system by stimulating the secretion of bicarbonate-rich pancreatic juice. The discovery of secretin was a significant milestone in the history of endocrinology and paved the way for the discovery of other hormones that regulate various physiological responses in the body.