Pancreas Flashcards
what are the roles of acinar cells of the pancreas?
synthesize proteins, secrete digestive enzymes, secrete fluid
what are the roles of duct cells of the pancreas?
secrete bicarb, ion transport, fluid transport
what are the roles of goblet cells of the pancreas?
mucin secretion, lubrication, hydration, immune function
which molecules promote both fluid and enzyme secretion in the pancreas?
CCK and Ach
what are the protective mechanisms against activation of digestive enzymes within the pancreas?
- inactive forms 2. vesicles contain a trypsin inhibitor 3. low pH of vesicle prevents enzyme activation
how do enzymes get activated in the duodenum?
via enteropeptidase, which converts trypsinogen to trypsin
which molecule regulates protection of the duodenal epithelium?
secretin
what is the mechanism for secretin-mediated protection of duodenal epithelium?
- secretin is secreted by duodenum and stimulates pancreatic duct cells 2. chloride is taken up into duct cell in exchange for bicarb (net secretion of bicarb)
what is the negative feedback mechanism for acid secretion in the duodenum?
- via secretin (at level of the stomach) 2. increase release of somatostatin 3. decrease gastrin secretion 4. decrease proton pump expression
when are pancreatic secretions highest?
during intestinal contractions
what are the regulators of cyclical pattern of pancreatic enzyme secretion in the interdigestive state?
- stimulation of parasympathetic pathways 2. stimulation of CCK 3. inhibition by a-adrenergic input, somatostatin, peptide YY
what is the main regulator of pancreatic enzyme secretion in the well fed state?
CCK
what are the stimulants for the intestinal phase of pancreatic enzyme secretion? what is the main regulator?
- amino acids, fatty acids, protons 2. CCK
what is the most potent stimulus for I cell secretion of CCK?
lipids
