exocrine pancreas
Digestive enzymes - acinar cells (exocrine)
Bicarb + water - epithelial cells
control of pancreatic exocrine secretion
neural
- ⊕ parasympathetic (via vagus nerve) stimulation
- ⊖ sympathetic stimulation
hormonal
- ⊕ secretin - alkaline fluid from ductal cells
- ⊕ cholecystokinin - enzyme-rich fluid from acinar cells
- ⊖ somatostatin
- ⊖ sympathetic stimulation - all pancreatic secretions
| Hormone | Where released | Trigger | Stimulation | Inhibition | Action |
|---|---|---|---|---|---|
| Secretin | duodenal S cells | acid contact with duodenal walls (from acidic chyme) | Parasympathetic stim (via vagus nerve) | H2 inhibitors Somatostatin |
stimulates the production of bicarbonate and water by the pancreas stimulates bile production in the liver inhibits gastric acid production by the parietal cells of the stomach. |
digestive enzymes
- Trypsinogen
- can be activated by trypsin itself
- prevented by trypsin inhibitor (↓ secretion in e.g. pancreatitis hence autodigestion)
- Chymotrypsinogen
from Guyton