Final answer:
The hormone responsible for the release of bicarbonate from the pancreas is called secretin. It is released in response to acidic chyme entering the duodenum, and stimulates the pancreas to produce an alkaline bicarbonate solution that neutralizes stomach acid and supports digestion.
Step-by-step explanation:
The hormone that stimulates the release of bicarbonate substance from the pancreas is known as secretin. Secretin is a hormone released in the small intestine, specifically when the acidic chyme from the stomach enters the duodenum. This prompts the pancreas to release a bicarbonate-rich substance. The sodium bicarbonate, an anion contained within the pancreatic juice, acts to neutralize the pH of the ingested food content, creating an optimal environment for the activity of digestive enzymes.
The regulation of pancreatic secretion involves both hormones and the parasympathetic nervous system. When acidic chyme enters the duodenum, secretin is released, leading to the secretion of bicarbonate-rich pancreatic juice. Concurrently, the presence of proteins and fats in the duodenum stimulates the secretion of cholecystokinin (CCK), which also plays a role in enzyme release from the pancreas. However, it is secretin that directly triggers the duct cells to release sodium bicarbonate, neutralizing the stomach acid and aiding digestion.