Pancreatic enzymes Flashcards
What secretes digestive enzymes
Acinar cells
Pancreatic islet includes…
Alpha, beta and acinus
Alpha cells secrete
glucagon
Beta cells secrete
insulin
Which cells produce bicarbonate?
Centrocinar cells
2 main pancreatic proteases in zymogen form
Trypsinogen and chymotrypsinogen
Cephalic stage
Vagal innervation and gastrin production in response to seeing food/smelling food
Second stage
Low level stimulus in anticipation of a meal
Stimulus for secretin
Low duodenal pH
Where is secretin produced?
Upper small intestine
What does secretin do?
Pancreatic water and bicarb secretion (carrying enzymes)
What stimulates cholecystokinin?
HCl, protein and fats entering duodenum
Where is cholecystokinin produced?
I cells of duodenum and jejunum
What does cholecystokinin do?
Pancreatic enzyme and bicarbonate secretion
Gallbladder contraction
Inhibition of gastric acid secretion
Delays gastric emptying
What stimulates gastrin?
Gastric distension and irritation
Where is gastrin produced?
G cells in stomach
What does gastrin do?
HCl secretion (parietal cells) and enzyme release (acinar cells)
Where is bicarbonate secreted from
Epithelial cells in pancreatic duct
What does bicarbonate do?
Protects duodenal mucosa by neutralising stomach acid, buffers to optimise pH for enzyme digestion
What stimulates enzyme secretion?
Gastrin and CCK
As proteins and fats digested, pH rises meaning
Stimuli for CCK and secretin disappear and pancreatic secretion reduces
What are consequences of pancreatic exocrine insufficiency?
Malnutrition,
Osteoporosis,
Increased cardiovascular morbidity,
Symptom burden
