Pancreas Flashcards
What percentage of pancreas is endocrine and exocrine
excrine = 85% endocrine = 1-2%
Function of exocrine and endocrine pancreas
Secrete digestive enzymes, ions and water into SI
Endocrine function is to secrete hormones, primarily involved in the regulation of glucose lipid and protien metabolism
What are the serous acinar glands
secretory units of pancreas
Each pancreatic acinus consists of pyramidal shaped acinar cells
These cells produce the digestive enzyme precursors
What are intercalated ducts
Pancreatic secretions leave via these ducts
Lined with simple squamous epithlial cells called centroacinar cells
Signify beginning of the ductal system
Explain the duct system of exocrine pancreas
Centroacinar cells are the sites where it arises
Intercalated ducts are short and drain into the intralobular collecting ducts
intralobular ducts drian into interlobular ducts lined with columnar epithelium containing enteroendocrine and goblet cells
Interlobular ducts drain into main pancreatic duct
What is secretin and CCK effect in exocrine pancreas
secretin - stimualtes centroacinar cells to secrete large volume of fluid containing bicarbonate
CCK - causes acinar cells to secrete their zymogens
Name two pancreatic enzymes
Trypsin and chymotrypsin
How is trypsin and chymotrypsin activated
Typsinogen activated to trypsin by enterokinase
Chymotrypsinogen activated by trypsin along iwht other pancreatic proteolytic enzymes
What does the secretion of trypsin inhibitor prevent
Prevents pancreatic autodigestion
Prevents activation of trypsin inside the secretory cells and in the acini and ducts of pancreas
ALso prevents activation of other proteolytic enzymes
What are the functions of pancreatic polypeptide and amylin
Pancreatic polypeptide - released internally to self-regulate pancreas activities
Amylin - released with insulin, contributes to glycemic control
Cells present in islets of langerhans and what do they secret
Alpha cells - secrete glucagon
Beta cells - secrete insulin
Delta cells - somatostatin
What facilitates uptake of glucose from circulation
GLUT4 in skeletal muscle cells and adipocytes
Effects of insulin
Uptake of glucose Sotrage of glucose Utilisation of glucose Release of glycerol and fatty acids from LDL Synthesis of proteins
Effects of glucagon
Increased blood glucose levels Secreted by alpha cells Dtimulates glucose synthesis via gluconeogenesis Stimulates glycogenolysis Stimulates lipolysis
