Endocrine pancreas Flashcards
What are the main cell types in the islets and scattered in the exocrine pancreas and what do they secrete?
- Beta: insulin
- Alpha: glucagon
- delta: somatostatin
- PP: pancreatic polypeptide
What does glucagon do?
stimulates glycogenolysis in liver
What does somatostatin do?
suppresses both insulin and glucagon
What does pancreatic polypeptide do?
Stimulates secretion of gastric and intestinal enzymes and inhibits intestinal motility
What are the Rare cell types in the islets of Langerhans and what do they secrete
- D1 cells: VIP
- Enterochromaffin cells: serotonin
What does VIP do?
- induces glycogenolysis and hyperglycemia
- stimulates GI fluid secretion and causes secretory diarrhea
What is it called when there is a tumor of enterochromaffin cells secreting serotonin
carcinoid syndrome
during fasting you should have _____ levels of insulin and ______ levels of glucagon
- low
- high
Fasting plasma glucose levels are determined primarily by what?
hepatic glucose output
-Hepatic gluconeogenesis and glycogenolysis
the insulin precursor protein is proteolytically cleaved by what?
gives what and what?
- Golgi complex
- mature hormone and C-peptide
What can you measure in someone receiving exogenous insulin to determine how well B cells are functioning
C peptide levels
Describe the steps of insulin synthesis and secretion
- Glucose comes in through GLUT-2
- goes to mitochondria to produce ATP
- This ATP inhibits a K+ channel on the beta cells
- leads to membrane depolarization and influx of Ca
- this leads to secretion of insulin
effects of insulin on adipose tissue
- increase glucose uptake
- increase lipogenesis
- decrease lipolysis
effects of insulin on Striated muscle
-increase in glucose uptake, glycogen synthesis, and protein synthesis
effects of insulin on Liver
- decrease gluconeogenesis
- increase in glycogen synthesis
- increase in lipogenesis
A group of metabolic disorders with hyperglycemia from defects in insulin secretion and/or insulin action
Diabetes Mellitus
in Diabetes mellitus, chronic hyperglycemia and metabolic dysregulation is associated with secondary damage to what?
- kidneys
- eyes
- nerves
- blood vessels
In the US, what is the leading cause of end-stage renal disease, adult-onset blindness, and non traumatic lower extremity amputations
Diabetes mellitus
What ethnic groups are more likely to develop diabetes
- native americans
- african american
- Hispanics
What is normal blood glucose lever
70-120
- Diabetes: fasting plasma glucose >/= what?
- Random glucose level of what (in a patient with classic hyperglycemic signs)?
- 2 hour plasma glucose of what during an oral glucose tolerance test (OGTT) with loading dose of 75 gm?
- HbA1C (glycated hemoglobin) >/= what?
- 126
- greater than/equal to 200
- greater than/equal to 200
- > /= 6.5%
the tests for diagnosis of diabetes need to be repeated and confirmed on a separate visit except for which one?
the random blood glucose level in a patient with classic hyperglycemic signs
What acute stresses can lead to transient hyperglycemia?
-Severe infections, burns, trauma
What are the glucose levels for impaired glucose tolerance (Prediabetes)
- Fasting: 100-125
- 2 hour plasma glucose following 75 gm OGTT: 140-199
- HbA1C: 5.7-6.4%