Unit 1: Glucose/Electrolyte Homeostasis Flashcards
Role of insulin
- decrease blood glucose
- secreted by Beta cells within islets if pancreas
- insulin circulates blood stream to target certain cells and poor glucose into cell body out of blood stream
Role of glucagon
- Increases blood glucose
- secreted by alpha cells
- Glucagon travels in large amounts to the liver and stimulates production of glucose
Types of production of glucose that glucagon stimulates
- Lipolysis: metabolizes fat for energy
- Glycogenolysis: breaking down stored glucose called glycogen that is released as glucose
- Gluconeogenesis: production of glucose from amino acids and fatty acids
Importance of blood glucose levels
Important for energy and brain function
- hypoglycemia - low blood sugar levels
- hyperglycemia- diabetes mellitus
Role of aldosterone
- Saves sodium and water and loses potassium
- adrenal cortex secretes this
- increases renal reabsorption of sodium and excretion if potassium
- low blood sodium and/or high blood potassium stimulates the adrenal cortex to secrete aldosterone
- increases blood pressure as well
Role of calcitonin
- released in response to high blood calcium levels
- C cells in thyroid gland secrete calcitonin
- acts to lower blood calcium (secretes in urine or into bones)
The role of parathyroid hormone
PTH
- Raises blood calcium to normal
- released when blood calcium is low
- causes calcium in the blood to increase to norma via negative feedback
Type I diabetes
- inability to produce insulin from beta cells
- insulin dependent
- mostly in younger people
Type II diabetes
- insulin receptor failure
- cels do not respond to insulin
- usually in adults
- obesity is a major contributor
Hypervolemia
- excess fluid volume in the blood
- can be caused by heart disease (causing increased release of aldosterone which causes water retention)
- causes high blood pressure
Hypovolemia
- refers to low blood volume
- can be due to loss of blood (hemorrhage) or fluid like severe vomiting/diarrhea
- can cause low blood pressure
- can result in shock
Hypernatremia
- high sodium levels in the blood
- can be due to excessive sodium intake
- can also be due to deficiency in antidiuretic hormone , resulting in excessive loss of water
Hyponatremia
- refers to low sodium levels in the blood
- can be due to decreased sodium intake or excessive water intake
- or decreased water excretion from too much antidiuretic hormone
Hyperkalemia
- high blood potassium levels in blood
- can be caused by deficiency of the hormone aldosterone
- risk of cardiac arrest
Hypokalemia
- refers to low potassium levels in the blood
- can be caused by an excess of insulin
Hypercalcemia
- Refers to high calcium levels in blood
- can be caused by excessive parathyroid hormones
Hypocalcemia
- refers to low calcium levels in the blood
- can be caused by decreased parathyroid hormones or insufficient vitamin D intake
What is the standard glucose curve?
A series of points of reference for converting optical density readings into glucose readings
Fasted glucose ranges
Normal - 110 or below
Diabetes - 126 or higher
Borderline - 110-126 mg/dl