Flashcards in Exocrine Pancreas Deck (19):
Anatomically, how is the pancreas situated?
Retroperitoneal (apart from tail)
Which organ is the tail of the pancreas attached to?
Which part of the pancreas is derived from the ventral bud?
Which part of the pancreas is derived from the dorsal bud?
All of the pancreas apart from the uncinate process
Describe the blood supply to the pancreas.
Main blood supply = coeliac trunk (direct branch of aorta).
Head of pancreas = superior mesenteric artery
Describe the venous drainage of the pancreas.
Name the 2 substances that the exocrine pancreas secretes.
Which tissue of the pancreas secretes exocrine substances?
Which specific cells secrete HCO3?
Duct cells = Epithelial cells lining the duct
Why is HCO3 secreted?
In order to protect the duodenal mucosa from gastric acid.
Which hormone stimulates the release of HCO3?
Where is HCO3 secreted into?
The pancreatic duct lumen
Describe how HCO3- is secreted.
1. H+ is pumped out of the duct cell in exchange for Na+
2. H+ reacts with HCO3- in the blood to form carbonic acid which dissociates into H20 and CO2
3. CO2 diffuses into the duct. Carbonic anhydrase reacts H2O with the CO2 to form carbonic acid. This time it dissociates into H+ and HCO3-
4. The H+ is then pumped out again and the whole cycle starts again
Which specific cells secrete digestive enzymes?
Which hormone stimulates the release of digestive enzymes?
CCK - in response to proteins and triglycerides in the small intestine
Name two active digestive enzymes and their roles.
Alpha amylase: Converts starch to maltose
Lipase: Converts triglycerides to fatty acids
Name a precursor digestive enzyme.
Trypsinogen. Enterokinase splits off a peptide from trypsinogen to form the active enzyme trypsin. Trypsin then goes on to break down proteins.
Name the hormone that inhibits pancreatic exocrine secretion.
Somatostatin, produced by D cells in the islets of Langerhans