GI Pancrease and Liver Flashcards
What do acinar cells release?
Acinar cells of the pancrease release inactive Trypsinogen as well as active alpha-amylase
Lipase
Colipase Trypsin inhibitor.
What do duct cells of the pancrease release?
Secrete Bicarbonate
What do the Goblet cells of the pancrease release?
Secrete mucin.
Also have an immune function.
What is the primary stimulus for fluid and enzyme secretion by the pancrease?
Acetylcholine from PNS and ENS
CCK
What keeps zymogens stored in the pancrease from becoming activated?
Trypsin inhibitor keeps Trypsinogen inactivated along with a low pH in the storage vesicle.
What is the cascade for the activation of enzymes in the duodenum?
Trypsinogen is activated by enteropeptidase in the duodenal brush border.
Trypsin is then able to activate all other pancreatic zymogens.
What functions do the hormone Secretin have?
Secretin stimulated by low pH causes bicarb release from the pancrease.
Also increases D cell somatostatin release to lower stomach acidity.
What occurs during the cephalic stage of pancreatic secretion?
Stimulated by sight, smell, taste and mastication.
Vagal pathway causes 25% of maximum enzyme secretion to occur.
What occurs during the Gastric phase of pancreatic secretion?
Stimulated by distention, Gastrin
Vagal tone and gastrin cause 10-20% of enzymes to be released here.
What occurs during the intestinal phase of pancreatic secretions?
Amino acids, lipids, and fatty acids as well as H+ caused CCK to be released (From I cells) as well as Secretin (From Duodenal S cells) and the ENS.
What cell type releases CCK in the pancrease?
I cells
What cell type releases Secretin in the duodenum?
S cells in the duodenum.
What is responsible for returning the levels of pancreatic secretion from the fed state back to the interdigestive state?
Peptide YY and Somatostatin decrease pancreatic secretions.
