GI Secretions II- Pancreatic Flashcards
how does an ulcer result from H. pylori?
NH3 is bad for cells, so they produce cytokines (inflammatory response) which leads to mucosal damage
how does H. Pylori survive the acid environment of the stomach?
it goes into the mucus layer and produces urease. The NH3 that results neutralizes the gastric acid
how do NSAIDs cause ulcers?
It is lipophilic allowing it to get through the bilayer. It also inhibits prostaglandin synthesis (PG are cytoprotective for gastric mucosa by suppressing HCl)
what stimulates acid secretion?
parasympathetics (ACh) gastrin histamine
what inhibits acid secretion?
secretin- decreases gastrin somatostatin GIP- decrease gastrin Peptide YY prostaglandins
what are the three phases of neural control of acid secretion?
cephalic: vagus gastric: vagal, local nervous, gastrin stimulation intestinal: nervous and hormonal mechanisms
what are the duodenal hormones and what do they do?
gastrin- increase HCl secretin- acidic chyme stimulates intestinal and pancreatic buffer CCK- increase pancreatic enzymes GIP (glucose insulinotropic peptide)- stimulates insulin secretion in the pancreas
the majority of the parenchymal cells of the pancreas will be ___
exocrine
if you just had ___ you would be able to ingest the majority of the proteins you eat
trypsinogen
trypsinogen can be activated to trypsin by _____
enterokinase
chymotrypsinogen and pro-carboxypeptidase are activated by _____
trypsin
within the pancreas, _____ keeps trypsin from the activated state
trypsin inhibitor
the main electrolytes in feces are
HCO3- and K+, not NaCl
