Pancreas Flashcards
What is the exocrine function of the pancreas?
Secretes digestive enzymes into the GI tract
What is the endocrine function of the pancreas?
Secretes glucagon, insulin, somatostatin, and amylin
Endocrine cells of the pancreas are located in?
Islets of Langerhans
Alpha cells secrete?
Glucagon
Beta cells secrete?
Insulin and amylin
Delta cells secrete?
Somatostatin
What is the function of glucagon?
Increase blood glucose levels
Prevent hypoglycemia
What is glucagon’s target tissue?
Liver and adipose tissue
Glucagon stimulates the liver to do what?
Produce more glucose via glycogenolysis and gluconeogenesis
What else does glucagon stimulate the liver to produce?
Ketones
What are ketones?
Alternate fuel source that frees up glucose to maintain high blood glucose levels
What does Glucagon stimulate in adipose tissue?
Lipolysis
What does lipolysis of the adipose tissue produce and what are they used for?
Glycogen = used for glycolysis
Free Fatty Acids = ketogenesis
What stimulates glucagon?
Hypoglycemia/Catabolic scenarios (epinephrine/exercise, parasympathetic responses, also stress/fasting)
What inhibits glucagon?
Hyperglycemia
Somatostatin
Amylin
Amylin is secreted by the ___________ with ____________ during ____________
pancreas; insulin; eating
What is the function of amylin?
Manage glucose levels during eating
How does amylin work?
Sends feeling of “fullness” to brain
Inhibits glucagon/decreases blood glucose
Slows metabolism
What is amylin’s target tissue?
Pancreas and CNS
What parts of the CNS does amylin stimulate and what are the effects?
Hypothalamus - decrease appetite
Brainstem - inhibits metabolism in GI tract
What stimulates Amylin?
Eating/hyperglycemia
What are incretins secreted by?
Gut/intestines
What are two types of incretins?
Glucagon-like peptide 1 (GLP-1)
Glucose-dependent insulinotropic polypeptide (GIP)
What is the function of incretins?
Inhibit glucagon, stimulate insulin
What stimulate incretins?
Eating
What is the “incretin effect”?
There is a higher/larger insulin response to oral eating as opposed to IV admin glucose
What is the target tissue of GLP-1?
CNS and Pancreas
What does GLP-1 stimulate in the pancreas?
Inhibition of glucagon, stimulation of insulin
What does GLP-1 stimulate in the CNS?
Sense of fullness, decreased appetite
What is the target tissue of GIP?
Pancreas
What does GIP stimulate in the pancreas?
Stimulates both insulin and glucagon release
How are incretins affected in Type 2 DM? (GLP-1 and GIP)
Inhibited/ effect is diminished or no longer present
GLP-1 is inhibited
GIP favors glucagon release
How is T2DM treated? (in respect to incretins)
GLP-1 agonists, inhibit glucagon and stimulate insulin release
What are the functions of insulin?
Decrease blood glucose
Prevent hyperglycemia
Plasma potassium homeostasis
Anabolic role
What is insulin’s target tissue?
Liver
Muscle
Adipose tissue
How does insulin affect the liver?
Promotes glucose storage (glycogenesis)
Inhibits gluconeogenesis and glycolysis
Inhibits ketogenesis
How does insulin affect muscle tissue?
Stimulates glucose uptake and glycolysis
Promotes protein synthesis by stimulating amino acid uptake and inhibiting proteolysis
How does insulin affect adipose tissue?
Inhibits lipolysis
Promotes FFA and glucose uptake = glucose storage
What stimulates insulin?
Hyperglycemia
Ketoacids, glucagon, AAs, digestive enzymes
Parasympathetic stimulation
What inhibits insulin?
Hypoglycemia
Somatostatin
Epinephrine, norepinephrine
How does insulin affect plasma potassium homeostasis?
Insulin promotes intake of potassium into cells
Potassium leaves bloodstream (lowers blood K levels)
What is hyperkalemia? How is it treated?
High plasma potassium
PX may be given insulin to lower blood K
What is hypokalemia? What is important to know about it in regards to insulin?
Low plasma potassium levels
Giving a PX w/ hypokalemia insulin may be fatal
