Which one is mostly responsible for exocrine pancreatic secretion from the acinar cells? A)CCK B)Secretin C)GIP D)Ach

The answer is A) CCK (Cholecystokinin).

Here's a step-by-step explanation:

1. The pancreas has both endocrine and exocrine functions. The exocrine function involves the secretion of digestive enzymes from acinar cells into the small intestine.

2. These secretions are regulated by several hormones, including Cholecystokinin (CCK), Secretin, Gastric Inhibitory Peptide (GIP), and Acetylcholine (Ach).

3. When food enters the stomach and then the small intestine, the duodenum releases CCK in response to the presence of fats and proteins.

4. CCK then stimulates the acinar cells in the pancreas to secrete digestive enzymes.

5. Therefore, CCK is primarily responsible for exocrine pancreatic secretion from the acinar cells.

6. While Secretin, GIP, and Ach also play roles in digestion, they are not the primary hormones responsible for stimulating pancreatic acinar cells. Secretin primarily stimulates the secretion of bicarbonate to neutralize stomach acid, GIP slows down gastric emptying and Ach stimulates general digestive processes.