Role of glucagon in control of blood sugar levels - Higher

Negative feedback

In blood glucose regulation, there are two key hormones that are produced by the pancreas that work together to keep blood glucose levels at a set point:

When blood sugar rises in the blood, insulin is released by the pancreas and travels through the blood. The insulin binds to receptor cells in the liver and receptor molecules on muscle cells, causing them to take in and store the excess glucose as glycogen.

Other body cells also take in glucose and store it as body fat.

If the blood glucose level is too low, glucagon is released by the pancreas and travels through the blood. It binds to receptors on the liver, which causes the liver to break down the stored glycogen and release glucose back into the blood.

The coordination of these hormones to keep the blood glucose level at a set point is an example of a negative feedback mechanism. The two hormones act antagonistically - this means they have opposite effects to one another.

A flowchart to demonstrate negative feedback

How glucose is regulated

Blood glucose levelEffect on pancreasEffect on liverEffect on blood glucose level
Too highInsulin secreted into the blood. No glucagon is released.Liver converts glucose into glycogenGoes down
Too lowGlucagon is secreted into the blood. No insulin is released.Liver does not convert glucose into glycogen. Glycogen is converted to glucose.Goes up