During low levels of blood glucose however, glucagon release increases, activating the breakdown of glycogen to glucose in the liver, and glucose is released into the blood.
This is a good example of negative feedback control, as the lowering of blood glucose, for example, inhibits further insulin secretion. This is because glucose activates calcium channels.
A receptor is responsible for detecting a change in the body, while the effector corrects this.
The control centre organises these two together to elicit the response.
Figure 2: Blood glucose control by insulin and glucagon If the blood glucose level is too high, more insulin and less glucagon is released.
This causes cells to take in glucose from the blood, while the liver converts glucose to glycogen.
Clearly, this is another example of homeostasis and it is outlined in Figure 2.
Two enzymatic hormones are utilised by the body to control the interchange of glucose as an energy molecule and glycogen as a storage molecule.
If this does not occur, the circuit will continue to direct effectors to warm the body because the feedback will not be switched ‘off’.
Recent research, however has added another dimension to the accepted definition of homeostasis.