Pancreas Flashcards
What are the two major roles of pancreas?
Exocrine: secretes D-enzymes and HCO3- rich fluids
Endocrine: insulin, glucagon and somatostatin
Describe the structure of the exocrine pancreas.
Looks like a cauliflower (upside down) –> ducts and acini
What is the function of the pancreas acini?
Secretion of digestive enxzymes, other proteins, and ion and fluids
How are secretory enzymes stored in the pancreas acini?
Packed in zymogen ganules
Mention a few digestive enzymes secreted by the pancreas acini.
Lipase, alpha-amylase, trypsinogens, and ribonuclease
What other proteins is secretedby the acini?
Glycoprotein 2 (GP2), ATP, nucleotidases, and PAP
How is the secretion of pancreatic enzymes regulated?
Secretion are stimulated by cholecystokinin (CCK), which are secreted by I-cells in the dodenum
Where does the pancreas secrete enzymes to?
To the duodenum (Sphincter of Oddi)
Where is the enzymes secreted by the acini activated?
In the duodenum (lumen)
Describe the isotonic NaCl secretion and signaling in pancreatic acini.
Interstitial side: NKCC (Na/K/Cl cotransporter), Na/K ATPase, K+ channel, CCK receptor, ACh receptor
Luminal side: CaCC, Ca2+ channel (CaT1), Ca2+ ATPase (PMCa)
H2O paracellularly
Signaling pathway: increase in IP3 –> increase in PKC –> increase in Ca2+
What is the function of the pancreatic ducs?
Secretion of HCO3- rich fluids
Describe the channel composition of pancreatic duct cells.
Luminal side: HCO3-/Cl- exchanger, CFTR, K+ channel, ATP-, Ado receptors
Basolateral side: HCO3-/Na+ cotransporter, Na+/H+ exchanger, Na+/K+-ATPase, K+ channel, H+/K+ ATPase, secretin-, ACh-, VIP-, ATP receptors
How is HCO3- formed in the cell?
H2O+CO2 <-(CA)-> HCO3- + H+
Which techniques can be used to study pancreatic ducts?
Isolated perfused pancreatic duct, patch-clamp, Ussing chamber, microelectrodes, microperfusion, and flourescent dyes
True or false: There are parallels in acid/base transport between stomach and pancreas.
True
