Pancreatic Exocrine Fucntion Flashcards
Anatomy of the pancreas:
Parts and blood supply
The pancreas is split up into a head that lies close to the duodenal wall, a pancreatic neck and a tail which lies close to the spleen.
The pancreas is supplied by the pancreatic branches of the splenic artery. The head is additionally supplied by the superior and inferior pancreaticoduodenal arteries which are branches of the gastroduodenal (from coeliac trunk) and superior mesenteric arteries, respectively.
What are acinar cells?
Acinar cells are the exocrine (exo=outward) cells of the pancreas that produce and transport enzymes that are passed into the duodenum where they assist in the digestion of food.
Open into the duodenum at the same point as the common bile duct
What is the function of centroacinar cells?
They produce and secrete HCO3-
What is a duct cell function and how does it work?
Secrete bicarbonate in exchange for Cl- via CFTRs at the luminal membrane.
Therefore there is more HCO3- in the fluid leading to more water entering the pancreatic lumen due to the osmotic gradient
Also makes solution alkaline for neutralisation of stomach acid.
How is secretion of the pancreas controlled?
CCK - stimulated by HCL, protein and fat entering duodenum
Produced by I cells of the duodenum
Leads to enzyme and HCO3- secretions, gall bladder contraction and inhibition of gastric acid secretion
Secretin stimulated by low duodenal pH, produced by S cells of duodenum. Cause bicarbonate secretions of pancreas
Gastrin - gastrin distension — G cells in stomach — HCl secretions by parietal cells
Pancreatic secretions have a gastric, cephalic and intestinal phase:
Cephalic via vagus nerve - Sensory inputs such as sight, smell, taste - pancreatic secretions
Intestinal via secretin and CCK - when food enters duodenum
Gastric phase - entry of food into the stomach initiates the gastric phase of pancreatic secretion.
Why are bicarbonate secretions of the pancreas important?
It protects the duodenal mucosa by neutralising acid
Optimal pH for enzymes
Up to 1L/ 24 hours
Why is the pancreas not digested by its enzymes?
Refer back to Emmy email slide this is important
Because it produces in activated forms (ogen)
Only activated once in the small intestine
What is a common feature of pancreatic insufficiency?
Steatorrhea = fatty diarrhoea - greasy and wont flush
What may be the consequence of pancreatic dysfunction?
Disease can be due to the organ = parenchyma or be originated outside the organ = extra pancreatic disease
Malnutrition - due to malabsorption
Osteoporosis - weakening of bones
Parenchymal disease = chronic pancreatitis, cystic fibrosis, cancers of the pancreas
Extra = coeliac disease, IBD, diabetes
What is a decrease in muscle mass called?
Sarcopenia
How is the pancreas assessed?
Why is faecal elastase a good test?
CT scanning, MRIs, faecal elastase
Elastase is produced by the pancreas, not broken down or absorbed in the intestines and can therefore be measured in your stool.
Elastase involved in breakdown of all macronutrients …
How doe we treat exocrine dysfunction?
Enzyme replacement therapy
Smoking cessation
Treat underlying cause
What is the moist common CF mutation?
It is the delta F508del mutation
