Pancreatic Notes

Pancreatic Function
Pancreas Role
  • Crucial for digestion, produces substances regulating its own and other digestive organs' functions.
  • Neutralizes stomach acid by secreting bicarbonate.
  • Breaks down food via essential enzyme production.
Anatomy
  • Similar to salivary glands in structure, producing digestive enzymes.
  • Consists of ducts and acini; acinar cells line branching ductular system, emptying into the main pancreatic duct.
  • Regulates pH, making secretions alkaline.
  • Digestive enzymes produced in inactive forms (zymogens) to prevent self-digestion.
Function
  • Exocrine: Produces digestive enzymes (zymogens) by acinar cells, transported via bicarbonate-rich pancreatic juice to the small intestine for digestion of fats, proteins, and carbs.
  • Endocrine: Produces hormones like insulin and glucagon for blood sugar regulation, released directly into the bloodstream.
Ductular Secretion
  • S cells release secretin when pH is low, stimulating bicarbonate production by pancreatic ductal cells, neutralizing the acidic environment.
  • Chloride ions exchanged for bicarbonate; CFTR protein crucial for this process.
Acinar Secretion
  • CCK (cholecystokinin) is the main regulator, released by I cells in the small intestine in response to fats and proteins.
  • CCK stimulates pancreatic enzyme secretion directly and indirectly (via nerve endings).
  • Pancreatic enzymes stored in granules within acinar cells, released into pancreatic ducts when stimulated.
Pancreatic Enzymes
  • Stored as inactive proenzymes (e.g., trypsinogens) except for amylase and lipase, which are stored and secreted in active forms.
Hormones Regulating Pancreas
  • CCK: Stimulates pancreatic enzyme secretion, bile secretion, gallbladder contraction, and reduces gastric emptying. Originates from the duodenum and jejunum.
  • Secretin: Food in the intestine and CCK
  • Peptide YY (PYY): acts as a brake on the digestive system.
Acute Pancreatitis
  • Inflammation of the pancreatic gland; can return to normal after resolution.
    • Ranson Criteria
      1. Age > 55 years
      2. White blood cell count > 16000/uL
      3. Blood glucose > 200 mg/dL
      4. Serum LDH > 350 IU/L
      5. AST > 250 IU/L
  • Causes: Duct obstruction (cholelithiasis, ampullary obstruction), acinar cell injury (alcohol, drugs, trauma), defective intracellular transport.
  • Etiology: Gallstones, alcohol, iatrogenic causes (post-ERCP, surgery), idiopathic.
  • Symptoms: Epigastric pain, nausea, vomiting, tachycardia, hypotension.
Diagnosis of Acute Pancreatitis
  • Requires two of the following criteria: abdominal pain, serum amylase/lipase elevated three times the upper limit, and/or characteristic imaging findings.
  • Elevated amylase is not always indicative of acute pancreatitis.
Severity (Atlanta Revision 2013)
  • Mild: Absence of organ failure and local complications.
  • Moderate: Local complications and/or transient organ failure (