Understanding the Pancreas: Function, Location & Importance

The pancreas is a retroperitoneal gland (6–10 inches) with dual exocrine (digestive) and endocrine (hormonal) functions.

Anatomy

• Head (in duodenal C-loop), neck, body, tail (near splenic hilum).
• Ducts: Main pancreatic duct (Wirsung) joins common bile duct → major papilla (ampulla of Vater). Accessory duct (Santorini) → minor papilla.

Exocrine Function (99% of mass)

• Acinar cells secrete enzymes into ducts:
  • Amylase → carbohydrates
  • Lipase (+ colipase) → fats
  • Proteases (trypsinogen, chymotrypsinogen) → proteins
  • Nucleases → DNA/RNA
• Ductal cells secrete HCO₃⁻-rich fluid → neutralizes gastric acid.
• Regulated by CCK (enzymes) and secretin (bicarbonate).

Endocrine Function (1–2% = Islets of Langerhans)

• β-cells (60%): Insulin → glucose uptake, storage.
• α-cells (30%): Glucagon → glycogenolysis, gluconeogenesis.
• δ-cells: Somatostatin → inhibits insulin/glucagon.
• PP cells: Pancreatic polypeptide → regulates exocrine secretion.

Major Diseases

• Acute pancreatitis: Gallstones, alcohol → autodigestion. Ranson/APACHE score severity.
• Chronic pancreatitis: Recurrent inflammation → fibrosis, calcifications, exocrine/endocrine insufficiency.
• Diabetes mellitus: Type 1 (autoimmune β-cell loss); Type 2 (insulin resistance + β-cell failure).
• Pancreatic adenocarcinoma: 90% ductal; late presentation; 5-yr survival ~12%.
• Neuroendocrine tumors: Functional (insulinoma, gastrinoma) or non-functional.

Pancreas integrates digestion and metabolism – central to energy homeostasis.