Question

What are the roles of secretin and CCK.

Answer 1

Secretin:

1. Secretin is a peptide hormone that is secreted by the S-cells in the duodenum of the small intestine.
2. Secretin stimulates the release of pancreatic juice that is rich in bicarbonate ions.
3. This alkaline juice is required to balance the pH of the gastric chyme that enters the small intestine.

CCK or Cholecystokinin:

1. CCK is a peptide hormone secreted by the I-cells of the upper portion of the small intestine.
2. CCK is responsible for the digestion of fats and proteins.
3. CCK also stimulates the contraction of the gall bladder as well as the secretion of pancreatic juice.
4. CCK also leads to the secretion of bile juice.
5. Both pancreatic and bile juice are required to make the digested food alkaline since the acidic food cannot be processed in the small intestine.