What are three biological mechanisms that govern appetite and at least 3 psychological influences on appetite?

Answer 1

the first would be sensory, mouth, tongue, taste and texture of food, phsyical status of stomach size. One sensory effect of the stomach shrinking for example is the release of ghrelin which will stimulate the production of hunger peptides in the brain the second will be physiological, pasage of food from stomach to gut, liver function is it receives nutrients, the effects of insulin production etc. The third biological mechanism will be central, (brain) as the products of digestion exert an influence on the brain peptites and other neurotranmitters that regulate appetite such as cholcystekinin, neropeptide Y, serotonin and endorphins. Late in the digestive cycle the brain.will also come under the influence of gut peptides such as PYY3-36 as the volume of food passes through the gut; the amounts of this peptide being influenced by your weight. The brain will also come under the influence of leptin; a protein released by fat cells as they expand and in theory this expansion will oppose the production of hunger generating peptides. But this is about wanting food and there is surely another mechanism in the brain which is to do with liking food and this is the pleasure seeking brain which is influenced by dopamine - loinked to endorphin flows when we eat food we like or eat food rich in fagt and sugar. This confers reward value to food ( to which we can become over attached). This was a simple explanation - Any comments, or corrections or additions?