In blood glucose regulation, the hormone insulin plays a key role. When blood sugar rises in the blood, insulin sends a signal to the liver, muscles and other cells to store the excess glucose. Some is stored as body fat and some as glycogen in the liver and muscles.
If you have not eaten for some time, your blood glucose level may be low. So, the pancreas produces a second hormone called glucagon. This travels in the bloodstream to its target organ which is the liver. Here excess glucose had been stored as glycogen. The hormone glucagon instructs the liver to break down some of its stored glycogen into the blood. This raises your blood glucose level once again.
This is an example of negative feedback and homeostasis.
|Blood glucose level||Effect on pancreas||Effect on liver||Effect on blood glucose level|
|Too high||Insulin secreted into the blood||Liver converts glucose into glycogen||Goes down|
|Too low||Glucagon, not insulin, is secreted into the blood||Liver does not convert glucose into glycogen. Glycogen is converted to glucose.||Goes up|