Controlling blood glucose and diabetes · GCSE Biology

Controlling blood glucose

Blood glucose concentration is monitored and controlled by the pancreas.
If blood glucose is too high, the pancreas releases insulin. Insulin makes glucose move from the blood into cells.
In liver and muscle cells, excess glucose is converted into glycogen for storage.

If blood glucose is too low, the pancreas releases glucagon.
Glucagon makes liver cells convert glycogen back into glucose, which is released into the blood.
Insulin and glucagon work against each other in a negative feedback cycle to keep blood glucose steady.

In Type 1 diabetes, the pancreas produces too little insulin, so blood glucose can rise to dangerously high levels.
It is treated with insulin injections, usually several times a day, and by controlling carbohydrate intake.

In Type 2 diabetes, the body's cells no longer respond properly to insulin.
It is treated with a carbohydrate-controlled diet and regular exercise; medication may also be used.
Obesity is a major risk factor for Type 2 diabetes.

Insulin: A hormone from the pancreas that makes glucose move from the blood into cells.
Glucagon: A hormone from the pancreas that makes the liver convert glycogen into glucose.
Glycogen: A storage carbohydrate made from glucose in the liver and muscles.
Type 1 diabetes: A condition in which the pancreas produces too little insulin.
Type 2 diabetes: A condition in which body cells no longer respond properly to insulin.
Pancreas: The organ that monitors blood glucose and releases insulin and glucagon.
Negative feedback: A control system that reverses a change to keep conditions steady.