Pancreatic exocrine secretion Flashcards
1
Q
Exocrine secretion
A
– Aqueous bicarbonate secretion
– Enzyme secretion
2
Q
Enzyme secretion
A
- Cephalic stage- innervation via vagus nerve
- gastric
- Intestinal stage- secretin & cholecystokinin
3
Q
Bicarbonate secretion
A
- Total 1 litre/24 hours
- Bicarbonate secretion protects duodenal mucosa by neutralizing acid
- Buffers duodenal contents to optimise pH for enzyme digestion
- Resting phase maintains low flow-predominantly Na+ & Cl- ions
- High flow rates Na+ & HCO3- ions
4
Q
Enzymes – proteases
A
- Proteases (trypsin & chymotrypsin)
- Digest proteins and peptides
- Peptide to amino acid digestion by other proteases
5
Q
Pancreatic lipase
A
- Triglyceride digestion by hydrolysis
- Dietary fat absorption highly dependent on pancreatic & hepatic secretion
- Key feature of pancreatic insufficiency is steatorrhoea
6
Q
Amylase & others
A
• Amylase hydrolyses starch to maltose & dextrins
• Others…
Gelatinase, elastase, ribonuclease, deoxyribonuclease
7
Q
Exocrine dysfunction
A
• Approx 11000 adult pt/year in UK develop PEI
• 7000 pancreatic cancer, 4000 chronic pancreatitis
• Consequences are significant
– Malnutrition
– Osteoporosis
– Increased cardiovascular morbidity
– Significant symptom burden
8
Q
Assessment of pancreatic structure & function
A
Imaging: • USS • Pancreatic EUS • CT scanning • MRCP Direct tests: • Lundh test meal • Secretion MRI • ERCP • Histology Indirect tests • Faecal fat (100g fat 5 days) • Triolein breath test • Pancreolauryl test • Faecal chymotrypsin • Faecal elastase
9
Q
How do we treat exocrine dysfunction?
A
• Pancreatic enzyme replacement therapy – Creon (protease, lipase & amylase) • Assessment of bone health • smoking cessation • Treat underlying cause
