Secretin is a polypeptide hormone produced by the small intestine. It is spelled as /siːkrətn/ in IPA phonetic transcription. The first sound is the "s" sound, followed by the long "e" sound, "k" sound and the "r" sound. The "ə" represents the schwa sound, while "t" and "n" are pronounced separately. So, altogether, secretin is pronounced as "see-kruh-tn". Correct spelling of this word is important in the context of medical research and communication between healthcare professionals.
Secretin is a peptide hormone that is primarily produced in the duodenum lining of the small intestine. It serves as a vital component of the secretory pathway that regulates the digestive process. The hormone is secreted into the bloodstream in response to the presence of acid and partially digested food in the duodenum, triggering the release of digestive enzymes and bicarbonate ions from the pancreas and bile from the liver.
Secretin acts by stimulating the cells in the pancreas to secrete bicarbonate ions, which increases the pH level of the chyme in the intestine. This action helps to neutralize the acidic content and creates an optimal environment for the action of digestive enzymes. Additionally, secretin stimulates the liver to increase bile production, promoting the emulsification and absorption of fats. This hormone also inhibits the secretion of gastric acid in the stomach, consequently reducing stomach acidity.
Secretin plays a crucial role in the regulation of the digestive system, ensuring the proper breakdown and absorption of nutrients from ingested food. By maintaining an appropriate pH, it aids in preventing damage to the gastrointestinal tract caused by excessive acidity. Additionally, secretin regulates the volume of pancreatic and biliary secretions, contributing to the efficient digestion and absorption of nutrients.
In summary, secretin is a hormone secreted in response to the presence of acidic and partially digested food in the duodenum. It regulates the digestive process by stimulating the pancreas to release bicarbonate ions, increasing pH levels and promoting optimal enzymatic activity. It also enhances bile production and reduces gastric acid secretion, contributing to efficient nutrient absorption and digestion.
The word "secretin" is derived from the Latin word "secretio", which means "a secretion". It was coined in 1902 by the British physiologist Sir William Bayliss and the British physician Ernest Starling, who discovered this hormone while studying the digestive system. The name "secretin" was given to this hormone because it stimulates the secretion of digestive fluids in the small intestine.