Blood glucose regulation
Negative feedback
If you have not eaten for some time, your blood glucose level may be low. This causes the pancreas to produce a second hormone called A hormone produced by the pancreas that promotes the breakdown of glycogen into glucose in the liver..
This travels in the bloodstream to its target organ - the liver, where excess glucose has been stored as glycogen.
The hormone glucagon instructs the liver to break down some of its stored glycogen into glucose. This is released into the blood. This raises your blood glucose level once again.
If the blood glucose concentration gets too high, receptors on the pancreas respond to the increase and increase the production of insulin that causes glucose to move from the blood into the cells.
This is an example of negative feedback and The maintenance of steady conditions. The ability of the body to maintain a constant internal environment, eg temperature and blood glucose concentration..
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 | 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 |
| Blood glucose level | Too high |
|---|---|
| Effect on pancreas | Insulin secreted into the blood |
| Effect on liver | Liver converts glucose into glycogen |
| Effect on blood glucose level | Goes down |
| Blood glucose level | Too low |
|---|---|
| Effect on pancreas | Glucagon, not insulin, is secreted into the blood |
| Effect on liver | Liver does not convert glucose into glycogen. Glycogen is converted to glucose. |
| Effect on blood glucose level | Goes up |
Adrenaline
Adrenaline (also known as epinephrine) is a hormone produced in the adrenal gland. It is released when the body is under acute stress or during exercise. It increases blood flow to the skeletal muscles and the level of glucose in the blood.
For this reason it is sometimes called the 'fight or flight' hormone - it gives the body a quick energy boost to respond to danger.
Adrenaline stimulates the liver to break down glycogen into glucose. This is released into the blood stream.