Control of Blood glucose concentration Flashcards
Control of Blood Glucose Levels
If high = should be in cells for respiration, also lowers blood water potential
If low = not enough to supply cells of the brain, also increases blood water potential
controlled by the Pancreas
contains the Islets of Langerhans
made of alpha and beta cells
alpha cells produce glucagon
beta cells produce insulin
What happens with High Blood Glucose Levels?
Insulin is released
Most cells in the body have complementary receptors (particularly muscle, liver, brain cells)
Causes increase in glucose channels and carriers
Glucose taken up and used in respiration
In muscle and liver cells, glucose also converted into glycogen for storage (glycogenesis)
In liver cells, glucose also converted into fat
What happens with Low Blood Glucose Levels?
occurs after starvation or exercise
glucagon is released
only liver cells have complementary receptors
converts glycogen into glucose (glycogenolysis)
converts fats and amino acids into glucose (gluconeogenesis)
glucose is released into blood
Glycogenisis
Glycogenolysis
Gluconeogenesis
The factors that influence blood glucose concentration.
The second messenger model of adrenaline and glucagon action.
Diabetes
Person loses control of blood glucose levels
normally high (hyperglycemia)
Type 1 starts at a young age, a person does not make insulin, beta cells are damaged by an autoimmune disorder (treatment = insulin injections)
Type 2 starts in middle age, person makes insulin but cells are less sensitive, caused by obesity and a diet high in simple sugars (treatment = diet and exercise, drugs, insulin injection)
Symptoms = tiredness, increase urination, thirst
Diagnosis = high blood glucose levels on random testing & blood glucose levels remain high following a fasting blood glucose test (person fasts for a number of hours, then consumes a drink of glucose, should normally rise then decrease due to insulin)
