Pancreas Flashcards
Is the pancreas more of an exocrine or endocrine gland
95% exocrine
5% endocrine
What is the functional unit of the endocrine pancreas
Pancreatic islets aka Islets of Langerhans
What are the 4 islet cells and what doe they produce
Alpha=glucagon
Beta=insulin
Delta=GHIH aka somatostatin
F cells (aka PP cell)= pancreatic polypeptide
What effect does Glucagon have on the body
Raises blood glucose levels by:
- stimulating glycogenolysis
- stimulates lipolysis, so BG is spared
How is Glucagon regulated
Through negative feedback from serum glucose levels
-receptors in pancreas sense glucose levels
What effect does Insulin have on the body
Lowers blood glucose levels by:
- facilitates glucose uptake by cells
- stimulates glycolysis (use of glucose to make ATP)
- stimulates glycogenesis (formation of glycogen)
How is insulin regulated
Through negative feedback from serum glucose levels
OR
Food in the small intestine triggers release of Glucose-dependent insulinotropic peptide which causes insulin to be released
Describe the relationship between insulin and glucagon
They are both continually being produced but the one that is more dominant at any given time is based on their concentrations
What is the effect of Somatostatin from the pancreas
aka GHIH
- Effect not clear, but actions are concentration based . It acts in a paracrine manner to inhibit insulin and glucagon
- Also as traditional exocrine manner and inhinits HGH release from anterior pituitary
What is the effect of pancreatic polypeptide
Effect not clear, but actions are concentration based but it does inhibit somatostatin release from pancreas, inhibits gallbladder contraction, and inhibits secretion of certain pancreatic exocrine enzymes
-may play a role in appetite suppression
True or False Insulin and HGH are needed for growth
True
