Exocrine pancreas Flashcards
What are the exocrine cells of the pancreas?
Acinar cells
What are the 2 membranes of the acinar cells?
Apical membrane and basolateral membrane
What are zymogens?
Precursors of enzymes stored in secretory vesicles
What is the function of the basolateral membrane?
Transport nutrients into acini for synthesis of digestive enzymes and trigger the release of enzymes for secretory vesicles via apical membrane
What causes enzymes to be released from the apical membrane of acinar cells of the pancreas?
Peptide hormones binding to receptors on the basolateral surface
By which 2 mechanisms is secretion form the exocrine controlled?
Neural and endocrine
What nerve controls exocrine pancreatic secretions?
Vagus
When does the vagus nerve stimulate the pancreas to secrete digestive enzymes?
In anticipation of a meal
What 2 hormones control exocrine pancreatic secretions?
CCK and secretin
When is CCK released?
In response to partially digested proteins and fats int he gut
When is secretin released?
In response to acid in the duodenum
What does secretin cause to be released from the pancreas?
Bicarbonate to neutralise the acids
Both CCK and secretin effect exocrine pancreatic secretions. How do they cause these effects?
Bind to specific receptors on the basolateral membrane of the acini
Proteases are secreted from the apical membrane of acini. They are packaged as zymogens in secretory vesicles. How do they become the active form?
Enteropeptidase in the duodenum
What enzyme is secreted from the pancreas to break down fats?
Lipase
