Final answer:
Secretin is released by the duodenum in response to acidic chyme to release pancreatic bicarbonate and enzymes.
Step-by-step explanation:
Secretin is released by the duodenum in response to acidic chyme. Secretin's function is the release of pancreatic bicarbonate and enzymes. When acidic chyme enters the duodenum, it stimulates the release of secretin hormone, which then causes the duct cells of the pancreas to release bicarbonate-rich pancreatic juice. This helps neutralize the acidic chyme and facilitates the digestion process.