Pancreatitis Flashcards
What are the two components of pancreatic juice?
- ↓ vol, viscous, enzyme-rich - Acinar cells
* ↑ vol, watery, HCO3- rich - Duct & Centroacinar cells
What are zymogens?
Pro enzymes
What are the enzymes synthesised and stored in zymogen granules?
Enzymes for digestion of:
• fat (lipases)
• protein (proteases)
•carbohydrates (amylase)
what is the problem for an organ making a cocktail of digestive enzyme?
- Autodigestion
- Acute pancreatitis
What are the protective mechanisms in place?
- Proteases are released as inactive pro-enzymes
- protects acini & ducts from auto-digestion - Pancreas also contains a trypsin inhibitor to prevent trypsin activation
- Enzymes only activated in duodenum
What enzyme does duodenal mucosa secrete? What does it do?
-Enterokinase (enteropeptidase)
•converts trypsinogen → trypsin.
What does trypsin do?
Trypsin then converts all other proteolytic & some lipolytic enzymes
What is acute pancreatitis?
•Rapid onset inflammation of the pancreas
What is chronic pancreatitis?
•Long-standing inflammation of the pancreas
What is the aetiology of acute pancreatitis?
G – gallstones
E – ethanol (alcohol)
T – trauma
S – steroids
M – mumps and other viruses (EBV, CMV)
A – auto-immune (Polyarteritis nodosa, SLE)
S – scorpion/snake bite
H – hypercalceamia, hypertriglyceridaemia, hypothermia
E – ERCP
D – drugs (SAND: steroids and sulphonamides, azothioprine, NSAIDS,
diuretics [loop/thiazide])
What is some pathogenesis of acute pancreatitis?
•↑ permeability of pancreatic duct epithelium (Alcohol, acetylsalicylic acid, histamine)
•Acinar cell enzymes diffuse into periductal interstitial tissue
•Alcohol ppts proteins in ducts → ↑ upstream pressure
•Pancreatic enzymes activated intracellularly
-proenzymes & lysosomal proteases incorporated into same vesicles → trypsin activated
What happens in cases of acute pancreatitis?
- usually conservative support sand management
1. Trypsin activated
What happens if trypsin is activated in acute pancreatitis?
- Activates:
1. Phospholipase A2
2. Elastase
3. Complement
4. prothrombin
5. Kallikrein
What happens when elastase is activated?
- Start eat (vessel arrosion) and blending (haemoragic pancreatitis)
- Islet necrosis, so decreased insulin so HYPER-GLYCAEMIA
What happens when prothrombin is activated?
- Activates thrombin
- Thrombosis
- Causes ischameia (pain) (and pancreatic gangrene)
What happens when phospholipase A2 is activated?
- Fat necrosis (saponification), casques Ca2+ sequestration
- Hypalbuminaemia
- Both cause hypokalaemia
What happens with kalikrein?
- Bradykinin, Kallidin
- Vasodilation and plasma
- Cause shock
What happens if there is systemic damage?
- Hypoxia (from fat necrosis fatty acid and phopshlipae A2 interfere with surfactants off lung)
- Anuria