GLOSSARY

Pancreatic juice is the alkaline (pH about 8) exocrine secretion of the pancreas, about 1–1.5 litres per day, delivered through the pancreatic duct into the duodenum; it contains bicarbonate and the most important digestive enzymes for all three macronutrients.

Composition

• Bicarbonate (from duct cells): neutralises acidic chyme.
• Proteases (as inactive precursors): trypsinogen, chymotrypsinogen, proelastase, and procarboxypeptidase.
• Pancreatic amylase: digests starch.
• Pancreatic lipase and colipase: digest triglycerides.
• Phospholipase A2 and cholesterol esterase.
• Nucleases: DNase and RNase.

Regulation of Secretion