Diabetes and Dyslipidemia Flashcards
Exam 4
What are the 2 major types of secretory tissues of the pancreas?
Exocrine gland (digestive enzymes)
Endocrine gland (Islets of Langerhans)
What are the 5 cell types of islets of Langerhans?
Alpha, beta, delta, G cell, and F cell
What do the alpha Islets of Langerhans cells secrete?
glucagon and proglucagon
What do the beta Islets of Langerhans cells secrete?
insulin, C-peptide, proinsulin, amylin
What is the role of amylin?
suppressed the production of glucagon
_____ is the opposite of insulin
glucagon
What do the delta Islets of Langerhans cells secrete?
somatostatin
_______ blocks the release of glucagon and insulin
somatostatin
What is the main type of cells of the Islets of Langerhans?
Beta cells - 75%
Alpha cells - 20%
Insulin receptors are _____
RTKs - receptor tyrosine kinases
When insulin binds to insulin receptors, what occurs inside the cell?
Glucose transporters migrate to cell surface
What is the normal blood glucose?
90 mg/dL
Describe the homeostatic response to increased blood glucose
Increase in blood glucose → pancreatic beta cells release insulin → body cells take up more glucose and liver takes up glucose and stores it as glycogen → blood glucose levels decline to set point
Describe the homeostatic response to decreased blood glucose
Decrease in blood glucose → pancreatic alpha cells release glucagon → liver breaks down glycogen and releases glucose into the blood → blood glucose levels rises to set point
What are the 4 types of diabetes mellitus?
Type I - Insulin dependent
Type II - Non-insulin dependent
Type III - Other causes elevated blood glucose (pancreatitis, drug therapy, etc.)
Type IV - Gestational
The breakdown of glycogen is also known as _______
glycogenolysis
The creation of glycogen is also known as _______
glycogenesis
What is the most common cause of type 1 DM?
Immune
- idiopathic less common
How high does glucose need to be to be excreted in urine? What is this called?
160 mg/dL
- renal threshold
What are the 3 typical signs of all diabetes?
Polyuria, polydipsia, polyphagia
Mellitus means _____
sugar
Type I DM is caused by what the destruction of ____, resulting in _____
beta cells
Severe or absolute insulin deficiency
What is the symptom of type 1 DM that differs from type 2?
weight loss
How is type 1 DM treated?
Require insulin replacement
If a patient with type 1 DM doesn’t take insulin, what happens?
Diabetic ketoacidosis (DKA)
Diabetic ketoacidosis causes a patient to have a _____ smelling breath
fruity
What is the patho behind type 2 DM?
Combination of relative deficiency of insulin secretion with tissue insulin resistance
What is the treatment for type 2 DM?
Exercise, treatment of obesity, medication
What are the clinical manifestations of type 2 DM?
- Recurrent infections, vision problems, neuropathy
- Dehydration – nonketotic hyperosmolar coma
What are the 4 chronic complications of type 2 DM?
- Hyperglycemia and nonenzymatic glycosylation - hemoglobin
- Hyperglycemia and the polyol pathway
- Sorbitol and fructose increase intracellular osmotic pressure (attracts water, leading to cell injury)
- Evident in the eye lens, nerves, RBCs
- Protein kinase C - Enzyme inappropriately activated by hyperglycemia
- Microvascular disease - Retinopathy
and Diabetic nephropathy
Prediabetic fasting blood glucose is ____
100-110 mg/dL
What is the normal fasting blood glucose?
70 mg/dL
Gestational DM occurs in __% of US pregnancies
7%
Normal HA1C is __. Target for DM patients is __
4%, 7%
How does gestational DM work?
Hormones block → Insulin resistance
How is DM diagnosed?
- Fasting Blood Glucose
- Glucose Tolerance Test
How is DM monitored?
- Self: Glucose POC
- Hemoglobin A1C
- Insulin
Insulin is a ____ hormone
peptide
The alpha and beta chains of insulin are held together via ______
disulfide linkages
Insulin is activated in the _____ before being released into the bloodstream
granules
The proform of insulin contains ______ which is _____ before entering the bloodstream
C-peptide
cleaved off
What is the function of C-peptide?
no known function
C-peptide is a measure of how much _____ function a patient has
beta cell
What is an insulin secretagogue? What are the different types?
increases release of insulin
- Glucose
- Amino acids
- Hormones
- Fatty acids
- Incretins
- Drugs – sulfonylureas, isoproterenol
The number one insulin secretagogue is _____
glucose
What are the transporters used to transport glucose into the beta cell?
GLUT2
Describe the effects of inward movement of glucose into pancreatic beta cells via GLUT2 transporters
excess glucose converted into ATP via metabolism → higher level of ATP binds to potassium channel - closing the channel → more positive Vrm → calcium channels open up → calcium enters beta cell → calcium triggers vesicle fusion and insulin exocytosis
How long does insulin last in the blood stream?
6 min
GLUT2 transporters have ____ affinity for glucose, meaning they have a ___ Km
low, high
Describe the pathway of insulin binding to its receptor
dimerization of units → insulin binds to receptor → beta units start internal signaling by becoming phosphorylated → IRS (insulin response substrates) activated → MAP kinase and IP3 pathways activated
Which glucose transporters have a high affinity for glucose?
GLUT1, 3, 5
Where are GLUT1 transporters located?
All tissues, especially RBCs and brain
GLUT4 transporters have a ____ affinity for glucose
medium