blood glucose regulation and diabetes
Type 1 diabetes
(diabetes mellitus) A condition that results when the homeostatic mechainisms that regulate blood glucose levels fail when insulin production fails. Characterised by a high blood glucose level higher than normal. Auto immune disorder.
what hormones are involved in blood glucose regulation?
- insulin - glucagon hormones bind to the receptors on the outsides of the cells.
why is blood glucose regulation important?
-respiration (energy production, ATP)
how is blood glucose transported?
blood
insulin
converts glucose into glycogen made in the beta cells of the islets of langerhans (pancreas)
glucagon
converts glycogen into glucose made in the alpha cells of the islets of langerhans (pancreas)
Identify the stimulus for the release of insulin
High blood glucose levels in the blood.
Identify the stimulus for the release of glucagon
Low blood glucose levels in the blood.
How does glucagon increase blood glucose levels?
Stimulates the breakdown of stored glycogen.
type 1 diabetes risk factors
family history the presence of certain genes in a persons genetic make-up.
where does blood glucose come from?
food digested to glucose
treatment of diabetes
insulin replacement- typically occurs via injection or insulin pump. type 2- lifestyle changes.
other organs involved in blood glucose regulation
liver- storage of glycogen muscles- uses glucose and stores some glycogen.
decrease in blood glucose negative feedback loop
stimulus- decrease in blood glucose receptor- alpha cells control centre- alpha cells secrete the hormone glucagon effectors- liver cells and body cells response- liver cells release glucose from glycogen, other cells make glucose.
increase in blood glucose negative feedback loop
stimulus- increase in glucose receptor- beta cells control centre- insulin sensitive cells of the hypothalamus, beta cells secrete the hormone insulin. effectors- liver cells and the body cells response- decrease in blood glucose by uptake by liver cells and conversion to glycogen and uptake by body cells.
glycogen
storage molecule for glucose
symptoms of diabetes- low energy levels, fatigue, extreme hunger, possible weight loss.
arise because the bodies cells are derived glucose and therefore energy. - loss of glucose from the body in urine can cause a loss of calories which can lead to weight loss.
symptoms of diabetes- increased thirst, frequent urination
arise in response to high blood glucose levels. - the body increases its output of urine in an attempt to remove the excess glucose from the blood. - frequent urination causes excessive water loss from the body and therefore increased thirst.
type 2 diabetes risk factors
obesity a diet of heavy fat and low fiber. low levels of physical activity family history of diabetes.
how does insulin decrease blood glucose levels?
promotes the uptake of glucose in the bodies cells and the conversion of glucose to glycogen in the liver.
diabetic ketoacidosis
type 1 diabetes. because the bodies cells cannot use their normal fuel, glucose, for energy production. instead the bodies cells metabolism fat for energy. the breakdown products of fat metabolism include acids called ketones. if ketones reach high levels in the blood the blood becomes more acidic, producing a serious condition called ketoacidosis.
symptoms of diabetes- blurred vision
untreated glucose blood levels can, over time, damage the capillaries in the retina of the eye.
type 2 diabetes
when the body's cells of a person do not respond to insulin (insulin resistant) - lifestyle disease: too high body to fat ration
