Flashcards in Lecture #4 -- Endocrine Pancreas Physiology Deck (66):
Where is blood sugar normally?
Right after a meal?
Fasting State -- 70-100 mg/dL
Post prandial state -- usually under 140 mg/dL
Common symptoms of low blood glucose
Sweating, Nervousness, Tachycardia, Dizziness
Common symptoms of high blood sugar
Polyuria, Polydipsia, Blurred Vision
Alpha cells produce...
Beta cells produce....
Insulin and Amylin
Delta cells produce
Epsilon cells produce...
F cells produce
Use of C-peptide measurement?
Measuring C peptide give you an idea how how much insulin is being generated endogenously (rather than injected)
Describe the structure of insulin
Two chains derived from proinsulin
Joined by two disulfide bonds
Describe the process of Insulin secretion
Glucose in through Glut2
Insulin used to make ATP
ATP closes K channel, Depolarization
Depolarization lets Ca in, allows exocytosis
Primary 5 effects of insulin
Promotes glucose/AA uptake and storage in target cells
Promotes Glycogen formation in Liver and Muscle
Stimulates lipid synthesis
Stimulates K uptake by cells
Two ways insulin promotes the formation of glycogen.
Stimulates glycogen synthase
Inhibits glycogen phosphorylase
Insulin receptos has _____ ____ ______ activity
Intrinsic Tyrosine Kinase
Insulin inhibits ______ to inhibit gluconeogenesis
Insulin activates _____ to convert glucose to glycogen
Other than glucose, four factors that regulate glucose
Amino acid affect on insulin release?
Ketoacid affect on insulin release?
Increase glu uptake to prevent lipid and protein utilization
Epinephrine affect on insulin release?
Adrenal epinephrine inhibits insulin to maintain blood Glu levels
Glucagon affect on insulin release?
Whats the incretin effect all about?
Glucose taken in orally will generate a much greater insulin response than insulin that is provided via IV. When digested, glucose is accompanied by costimulatory molecules that allow for heightened INS secretion.
Effect of Insulin on Glucose level?
Effect of Insulin on Fatty Acid level?
Effect of Insulin on Ketoacid level?
Effect of Insulin on Amino Acid levels?
Main target tissues of glucagon?
Liver, Muscle, and Adipose Tissue
How does glucagon work?
Binds to a Gs receptor, inc. cAMP, inc. PKA
Activates IP3 (inc. Ca)
Primary actions of Glucagon
Increases Ketoacid formation
Effect of Glucagon on Glucose blood level?
Effect of Glucagon on FA blood level?
Effect of Glucagon on Ketoacid blood level?
Normal Insulin/glucagon ratio
What happens to Ins/Glu ratio in prolonged exercise?
Ratio drops to 0.5:1
Want to maintain glucose to the brain
Gluconeogenesis in the liver also leads to production of what metabolic product?
Following a meal, what changes should you see in glucose, insulin, and glucagon levels
Increased Glucose and Insulin
Glucagon excess and insulin deficiency have ________ effects
Four regulators of glucagon release
Influence of glucose on glucagon release?
Influence of amino acids on glucagon release?
Influence of stress on glucagon release?
Epinephrine --> beta adrenergic receptors on alpha cells
Increased glucagon release
Influence of insulin on glucagon secretion
What is Necrolytic Migratory Erythema (glucagonoma syndrome)
Tumor of the Islet Cells
Erythematous, Scaly plaques, hyperglycemia, diarrhea, weight loss, and atrophic glossitis
Other that insulin and glucagon....what are three additional factors that regulate glucose homeostasis
Catecholemines (inc. glycogenolysis+lipolysis)
Growth Hormone (inc. glycogenolysis+lipolysis)
Glucocorticoids (inc. gluconeogenesis, proteolysis, and lipolysis)
Cortisol, GH, and GH move with what hormone?
Symptoms of Diabetes Mellitus
Increased Food Consumption
Four types of diabetes mellitus
Type I, Type II, pre-diabetes, Gestational diabetes
What happens in Type I diabetes?
Killer T cells target glutamate decarboxylase in the beta cells, killing the cells
Glu can't get into adipose, inc. blood glucagon
Type I diabetes is a Type ____ hypersensitivity reaction
Type I is associated with what receptor?
Symptoms of an untreated Type I diabetic
Weight low, low muscle mass, polyphagia
Polyuria, polydipsia, glycosuria
How is Type 1 treated?
What is diabetic ketoacidosis?
Serum ketoacids in blood
Caused by stress, infection, not taking insulin
Why does high glucagon lead to ketoacidosis?
Glu --Lipolysis--> FFAs --liver conversion--> ketones
Blood values expected in a DKA patient?
Hyperglycemia (over 250)
Anion gap metabolic acidosis
Non-blood observations of a DKA patient?
Mental status changes
How is DKA treated?
Fluids, Insulin, Electrolyte Replacement
Other than DKA, complications of Diabetes Mellitus
Vascular endothelium damage
How does hyperosmolar non-ketotic hyperglycemia present?
Sugars over 500
Life threatening diuresis
Three structures more prone to suffer osmotic damage in diabetics?
Pericytes of retinal blood vessels
Why is the lens a concern in hyperglycemia?
The lens takes up sugar without insulin
Blood values of a patient with an insulinoma?
Increased C-Peptide Levels
Increased Insulin Levels
What is a gastrinoma?
Gastrin secreting tumor of the pancreas
Symptoms of somatostatinoma?
Achloryhydria (inhib. of gastrin)
Inhibition of CCK
Cholelithiasis and steatorrhea
Symptoms of VIPoma?
Excessive VIP secretion
Watery diarrhea, hypokalemia, achlorhydria