GI Pancreas exocrine secreations Flashcards
What are the two phases of pancreatic juice secretion?
Aqueous alkali and Protien/enzyme phase
What type of glands are the exocrine glands of the pancreas?
Wholly serous secreting a water, enzyme rich, alkali secretion.
Where are the enzymes in pancreatic juice made?
The acinar cells of the pancreas.
What stimulates the release of pancreatic juice?
Food entering the duodenum.
What activates the enzymes in pancreatic juice?
High pH.
What causes increased secretion of bicarbonate from the pancreas?
Increased cAMP concentration due to increased VIP or secretin. stimulates duct cellls CFTR channels.
What causes increased secretion of enzymes in the pancreas?
CCK, ACh, Gastrin, Secretin and VIP.
Where are CCK and Secretin produced?
The duodenal wall.
What is the duct systemof the pancrease from the acini?
Acini, intercalated duct, interlobular ducts, main pancreatic duct.
What type of epithelium is the intercalated duct?
Simple cuboidal.
What is the purpose of the alkali phase of pancreatic secretions?
Neutralise gastric acid as it enters the duodenum.
What is the function of duct cells in the pancreas?
Regulate the secretion of bircabonate and to take up Cl- ions.
What are CFTR channels?
Cystic Fibrosis Transmembrane Conductance channels for the transport of HCO3- out of the cell and Cl- in.
What are tubulovesicles?
H+ pumps.
What happens in a resting duct cell?
CFTR channels are aggregated on the luminal surface of the cell not doing anything.
Tubulovesicles are near the luminal surface of the cell.
