BIOPSYCH 0505 Edition Lecture 18 Outline of Last Lecture I Energy A Energy delivered 1 Lipids 2 Amino acids 3 Glucose B Energy stored 1 Fat 2 Protein 3 Glycogen II Three places of energy metabolism A Cephalic phase B Absorptive phase C Fasting phase III Eating A What we eat 1 Evolution of tastes B When do we eat 1 Pre meal hunger 2 Conditioning of Hunger Current Lecture How much to we eat I A B II A B C III A B Hunger Peptides Ghrelin Neuropeptide Y Satiety Signals opposite of hunger signals What they do 2 phenomena s Sensory Specific Satiety Satiety peptides CCK Peptide YY These notes represent a detailed interpretation of the professor s lecture GradeBuddy is best used as a supplement to your own notes not as a substitute 1nd C Lepton Current Lecture How much to we eat I Hunger Peptides A Ghrelin 1 Produced and released by the stomach and a little is produced by duodenum and the pancreas 2 Levels increase during fasting and are highest before meals which results in perception of hunger 3 Levels then decrease after meals B Neuropeptide Y 1 Released in the hypothalamus specifically the arcuate nucleus 2 Increases appetite and is a potent stimulator of eating behavior 3 Higher levels correlate with hunger as lower levels are correlated to not eating even when food is available 4 Levels increase during fasting II Satiety Signals opposite of hunger signals A What they do 1 Help you to stop eating when you are full 2 Influenced by the food in gut the slower you eat the faster you will feel full 3 Influenced by glucose in the blood when it is high the body will know that you should stop eating 4 Influenced by the volume of food how much pressure is put on volume receptors 5 Also the nutritive density of food how high in sugar vitamins fats and energy is in the food the more nutrients the less you eat B 2 phenomenoms 1 Appetizer effect and satiety having an appetizer before a meal will make you more hungry triggers the cephalic phase with increased insulin levels 2 Social influences and satiety you eat more when with your friends prompted by others eating C Sensory Specific Satiety 1 Foods consumed and the sensory experience 2 Tasting food immediately decreases the positive incentive value of similar tastes 3 Decreases the palatability of all foods about 30 minutes later 4 Is adaptive and encourages a varied diet 5 There are some foods resistant to sensory specific satiety bread potatoes milk rice sweets salads III Satiety peptides A CCK 1 Secreted by the small intestines in response to fats 2 Higher levels of fats are signals of higher nutritional value 3 Slows down the rate of stomach emptying 4 Your intestines need time to absorb the nutrients so if you push too much food in the intestines at one time only a little bit of nutrients will get absorbed B Peptide YY 1 Secreted by cells in the ileum small intestines and the colon 2 Secretion is proportionate to the amount of calories consumed more calories more peptide YY 3 Inhibits the gastric motility which slows the movement of the food through the intestines to allow for absorption 4 Increases water and electrolyte absorption in the colon 5 Decreases eating C Leptin 1 Secreted by adipose cells fat cells 2 Inhibits the release of neuropeptide Y 3 Size of cells change not quantity 4 Tries to lower the levels of hunger because there is no need for energy 5 Decreases eating and increases the metabolic rate
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