Neural Mechanisms in Eating and Satiation
Homeostasis is a neural mechanism that detects whether or not the body has enough nutrients and if it does not, how to restore the nutrients. Homeostasis works on a negative feedback loop; this is because the time taken to eat a meal is shorter than the time taken to digest even a small amount of food. There are limitations to this explanation. To be adaptive the body must anticipate and prevent hungry instead of just responding to it, this shows that the explanation is not adaptive.
The dual centre theory involves to parts of the hypothalamus, the Lateral and Ventro Medial. The lateral hypothalamus contains the feeding centre and initiates eating behaviour. It responds to a number of things such as the decrease in blood sugar and an increase in the hormone ghrelin, which is a hormone which is produced then the stomach is empty. There are limitations of the LH. One limitation is that damage to the LH has found to cause problems with other bodily functions such as thirst and sex. This shows that the LH may still play a part in eating behaviour but it may not be the body’s ‘feeding centre’. NPY is an important transmitter that is used to turning on eating. However some research has questioned the important of NPY. Marie et al genetically manipulated mice so that they did not have NPY. She found that this did not cause any change in the rats eating behaviour. This shows that the NPY may not play an important role in turning on eating behaviour.
