Exocrine Pancreas Flashcards
Innervation of the pancreas
▪️sympathetic nervous system, splanchnic nerves, coeliac plexus
Lymph nodes in the abdomen
▪️coeliac lymph node above coeliac trunk
▪️superior mesenteric lymph node above SMA
▪️splenic lymph node by hilum of spleen
▪️anterior-pancreaticoduodenal lymph node above head of pancreas
▪️ posterior-pancreaticoduodenal lymph node behind head of pancreas
▪️pyloric lymph node next to pylorus
▪️hepatic lymph node by hepatic artery
▪️superior body lymph node on top of body of pancreas
▪️ inferior body lymph node underneath of body of pancreas
Exocrine pancreas cells
▪️acinar cells- grape like structure
▪️duct cells
▪️centroacinar cell- pancreatic stem cell
▪️make up 80% of cells of pancreas
Pancreas embryology
▪️develops from a dorsal and a ventral bud
▪️fuse during development
▪️made up of bud cells which form both exocrine and endocrine cells
-islets of langerhans
-acinar sells
-duct cells
Pancreatic polypeptide
▪️major regulator of endocrine and exocrine functions in the pancreas
▪️produced by PP-cells in islets of langerhans
Pancreatic acinar cells
▪️releases enzyme zymogen due to CCK binding
- inactive form of the enzyme which contains the enzyme and also a small protein so it is not active
-if it were to produce the active enzyme, the pancreas itself will be broken down
▪️trypsinogen cleaved to be trypsin by enterokinase in duodenum to breakdown protein into AA which then stimulates PP to stimulate more digestion
Pancreatic duct cells
▪️surround the duct of the pancreas
▪️secretin hormone binds to cells causing it to secrete HCO3 and water in to duct
-CFTR pumps Cl- and HCO3 out into lumen which allows water to flow into duct as well
Disease of the exocrine pancreas
▪️chronic pancreatitis- fibrosis in pancreas
▪️pancreatic cancer- 90% from the duct
Mechanism for pancreatitis
▪️trypsinogen activation within the pancreas due to high levels of Ca
▪️trypsin causes damage to the cells
▪️cytokines are released leading to an inflammatory response
▪️leads to pancreatitis and necrosis
▪️which leads to even more trypsinogen being activated early
-however, trypsin can be used to break down trypsinogen-autoregulation
Causes of acute pancreatitis
▪️I GET SMASHED
- I- idiopathic (genes)
- G- gallstones- most common
- E- ethanol- not as common
- T- trauma
- S- steroids
- M- mumps
- A- autoimmune
- S- scorpion sting
- H- hyper-calcaemia/thermia/lipidaemia
- E- ERCP- endoscopy of pancreas
- D- drugs
Causes of chronic pancreatitis
▪️alcohol - most common
▪️genes
▪️gallstone- rarely as they are removed
How does alcohol cause pancreatitis?
▪️non-oxidative metabolism
-leads to a calcium spike therefore pancreatitis
