Role of glucagon in control of blood sugar levels - Higher
Negative feedback
In blood glucose regulation, there are two key hormoneChemical messenger produced in glands and carried by the blood to specific organs in the body. that are produced by the pancreas that work together to keep blood glucose levels at a set point:
- insulinA hormone that regulates the level of sugar in the blood and can be produced by genetically modified bacteria.
- glucagonA hormone produced by the pancreas that promotes the breakdown of glycogen into glucose in the liver.
When blood sugar rises in the blood, insulin is released by the pancreas and travels through the blood. The insulin binds to receptor cellA cell that can detect stimuli inside or outside the body. in the liver and receptor molecules on muscle cells, causing them to take in and store the excess glucose as glycogenThe storage form of glucose in animal cells..
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 mechanismMechanism to lower raised levels of something, and to raise reduced levels of something.. The two hormones act antagonistically Describes when the effects of one thing are opposite to the effects of another. For example, the hormone insulin causes blood glucose levels to decrease but glucagon acts antagonistically because it causes blood glucose levels to rise. - this means they have opposite effects to one another.
How glucose is regulated
Blood glucose level | Effect on pancreas | Effect on liver | Effect on blood glucose level |
Too high | Insulin secreted into the blood. No glucagon is released. | Liver converts glucose into glycogen | Goes down |
Too low | Glucagon is secreted into the blood. No insulin is released. | Liver does not convert glucose into glycogen. Glycogen is converted to glucose. | Goes up |
Blood glucose level | Too high |
---|---|
Effect on pancreas | Insulin secreted into the blood. No glucagon is released. |
Effect on liver | Liver converts glucose into glycogen |
Effect on blood glucose level | Goes down |
Blood glucose level | Too low |
---|---|
Effect on pancreas | Glucagon is secreted into the blood. No insulin is released. |
Effect on liver | Liver does not convert glucose into glycogen. Glycogen is converted to glucose. |
Effect on blood glucose level | Goes up |