Pancreaticobiliary Secretion. Pancreatic juice consists of alkaline (chiefly bicarbonate) fluid and enzymes; 200–800 mL is produced each day. The enzymes, trypsin, lipase, and amylase are essential for digestion of most of the protein, fat, and carbohydrate in the meal.

Secretin enzyme stimulates the acinar cells of pancreas to secrete water and bicarbonate in pancreatic ducts that drain into the duodenum.

Pancreatic juice is produced by the pancreas and plays a crucial role in digestion. It contains various substances that aid in the breakdown of food and the absorption of nutrients. One of the main components of pancreatic juice is enzymes, which are responsible for the digestion of proteins, carbohydrates, and fats. However, pancreatic juice is also rich in water and electrolytes, which help in the transportation and regulation of nutrients within the body.

Pancreatic Juice Secretion:
The secretion of pancreatic juice is regulated by several hormones, including secretin, cholecystokinin (CCK), and pancreozymin. These hormones are released in response to the presence of food in the stomach and small intestine and stimulate the pancreas to secrete pancreatic juice.

Role of Secretin:
Secretin is a hormone that is released from the duodenum in response to the acidic environment created by the stomach. It acts on the pancreas to stimulate the secretion of pancreatic juice. Secretin primarily promotes the release of bicarbonate ions from the pancreatic duct cells. Bicarbonate ions help neutralize the acidic chyme from the stomach, creating an optimal pH for the action of digestive enzymes.

Pancreatic Juice Composition:
Pancreatic juice is composed of water, electrolytes, and enzymes. The water and electrolytes, such as sodium, potassium, and bicarbonate ions, help in maintaining the osmotic balance and pH of the digestive system.

Pancreatic Juice Enzymes:
Although pancreatic juice is rich in water and electrolytes, it is poor in enzymes. This is because the release of enzymes is primarily stimulated by another hormone called cholecystokinin (CCK). CCK is released in response to the presence of fats and proteins in the small intestine. It acts on the pancreas to stimulate the release of enzymes such as trypsin, amylase, and lipase, which are crucial for the digestion of proteins, carbohydrates, and fats, respectively.

In summary, pancreatic juice is rich in water and electrolytes, which help in maintaining the osmotic balance and pH of the digestive system. However, it is poor in enzymes and their release is primarily stimulated by cholecystokinin (CCK). Secretin, on the other hand, primarily stimulates the release of bicarbonate ions, which help in neutralizing the acidic chyme from the stomach.