Zusammenfassung der Ressource
Control of
blood glucose
- In humans, diet and exercise are two important lifestyle factors affecting blood glucose concentrations
- Diet. The glyceamic index (GI) is a system used to rank carboohydrate containing
foods based on their overall effect on blood glucose levels. Eating foods with a
high GI causes blood glucose concentrations to rise rapidly. Carbohyfrates from
foods with a low GI are absorbed into the bloodstream over a relatively long
period, helping to maintain stable blood glucose concentrations between meals
- Exercise; particularly anaerobic exercise, may make high demands on
blood glucose. In most circumstances, the increased metabolism
resulting form exercise triggers the conversion of glycogen stores in
muscle cells and liver cells to glucose, maintaing the blood glucose
concentration relatively constant. However, extremely stenous exercise
may result in a temporary reduction in blood glucose concentration
- Hormones; the most important internal factor that affects blood glucose
concentration is the interaction of hormones; insulin tends to reduce blood
glucose concentration while glucagon and adrenaline tend to increase
- The role of the liver. It plays a centeral role in metabolism,
regulating the concentrations of a wide range of chemicals in the
blood including glucose. The liver recieves, via the hepatic portal
vein, all the glucose absorbed into the blood through the intesinal
wall. The blood glucose concentration leaving the liver, it may be
reduced, or it may be increased
- Glucose can be added to the blood leaving the liver by;
- Glycogenolysis; 'glycogen splitting'
- hydrolysing glycogen to glucose
- Gluconeogenesis; 'new glucose formation' -
converting non-carbohydrate substances such
as amino acids and glycerol to glucose
- Glucose can be removed from the blood by;
- Glycogenesis; 'glycogen
forming' - condensing glucose
and storing it as glycogen
- Converting
glucose to
fat
- Using glucose as
a fuel for cellular
respiration