Maintaining Glucose Balance
Introduction to Glucose Regulation
Why do glucose levels need to be maintained?
Blood glucose levels must remain constant to maintain metabolic processes in the cell (cellular respiration). All cells require a constant supply of glucose as it is a source of energy for the cell's activities (including movement, reproduction and synthesis.
If glucose levels are too low (hypoglycaemia) then cellular respiration and metabolism slows, energy levels drop which limits the cells activities. The brain is extremely susceptible to low levels of glucose, which can lead to metal confusion, unconsciousness and seizures.
If glucose levels are too high (hyperglycaemia), this can cause damage to nerves, kidneys and eyes.
What can glucose be used for?
Glucose can be derived from carbohydrates in the digestion process. Glucose comes from the digestive system via the hepatic portal vein to the liver where:
Glucose may be used by liver cells
Glucose may be converted to glycogen for storage in the liver or muscle cells
Glucose may circulate through blood for cellular use (cellular respiration)
Glucose may be converted into fat
The islets of Langerhans have specialised cells (alpha and beta cells) in the pancreas which have a number of roles. They have chemoreceptors which detect the level of glucose in the blood. If blood glucose levels are low, alpha cells produce glucagon, and if blood glucose levels are high, beta cells produce insulin which both act to influence blood glucose levels.