CHAPTER 3 1 Hunger is the physiological drive for food Appetite Psychological desire for food o Satisfied by food o Nonspecific just hunger o Specific o Cravings o Body has all necessary nutrients o Psychological effect to consume food Hypothalamus regulates feelings of hunger and or satiation o Neuropeptide y and galanin stimulation activate food Satiety is the feeling of being full proteins have the highest satiety value high fat diet higher satiety value than carb diets high fiber descends from stomach and helps excrement solid foods o high satiety value o more filling than liquids 2 intake 3 4 5 6 7 digestion large molecules are broken down mechanically absorption process of nutrients being taken in through small elimination undigested food and waste is removed through intestinal wall the body Peristalsis the circular muscles that run along intestinal wall Segmentation Rhythmic contractions of the circular muscles pushing food through the GI tract along the intestinal wall mixes chime and enhances its contact with digestive enzymes and enterocytes Gastrin is a hormone secreted by the stomach lining cells that stimulates the gastric glands to produce gastric juices Parietal Cells Secret HCL and intrinsic Factors o Intrinsic factors glycoprotein produced by the parietal cells of the stomach It is necessary for the absorption of B12 and other vitamins Chiet cells Secret pepsinogen and gastric lipase Gastric juice is a colorless liquid present in promoting o Pepsinogen inactive precursor to pepsin digestion pepsin o Hydrochloric acid HCL denatures protein and activates o Pepsin Enzyme that digests proteins o Gastric lipase enzyme that digests fat o Intrinsic Factor protein that absorbs vitamins Bicarbonates main role is to help neutralize the very acidic contents coming out of the stomach and into the small intestine This serves a protective role to help protect the lining of the small intestine from being eaten away 8 Enzymes produces in GI tract Mouth stomach and Pancreas Mouth Amylase Carbohydrates Stomach Intrinsic Factor vitamins Gastric Lipase not extremely lipids Pepsin Proteins Pancreas Pancreatic Amylase Carbohydrates to be broken down in the small intestine Pancreatic Lipase Lipids that are broken down in the small intestine Protease breaks down proteins o All enzymes are used in the smaller intestine 9 Gastrin Secretin gastric utility o Produced and active in the stomach o Stimulates secretion of HCL and pepsinogen stimulates o Promotes Gastric proliferation of mucosal cells o Made in the small intestine Duodenum o Used in the pancreas stomach o Stimulates secretion of pancreatic bicarbonate neutralizing acidic chime and also decreases gastric motility in stomach o Made in small intestine Duodenum jejunum o Used in pancreas and gall bladder o Stimulates secretion of pancreatic digestive enzymes o Simulates gall bladder and slows gastric emptying in the Cholecystokinin CCK stomach Gastric inhibitory peptide o Made in the small intestine o Used in the stomach and pancreas o Inhibits gastric acid secretions slows gastric emptying and stimulates insulin release 10 Accessory organs that facilitate digestion salivary amylase Salivary glands produce saliva water mucus enzymes and Liver produce bile to digest fats Gall bladder stores bile before realease into the small intestine through the bile tract Pancreas produces digestive enzymes and bicarbonate which are released into the small intestine via the pancreatic duet 11 Food intolerance gastrointestinal discomfort caused by certain foods that is not a result of an immune system reaction Food allergy an allergic reaction to a food cause by the immune system CHAPTER 4 1 Most common monosaccharide Most common Disaccharide o Glucose o Fructose o Galactose o Lactose o Maltose o Sucrose 2 characteristics Glucose soluble in water monosaccharide o Most abundant o Brain power o Usually does not occur alone o 2 glucose make maltose a nutrient with 4Kcal o With glucose makes sucrose Fructose simple sugar found in many fruits and is considered Galactose not usually found alone formed when lactose is hydrolyzed into glucose and galactose 4 storage form of carbohydrates in animals Carbs are stored as glucose within the liver and muscle tissue Glucose is phosphorylated and metabolized for energy or stored as glycogen 5 break down lactose to digest Lactose intolerance is insufficient lactase or enzymes that Gas and cramping Mouth 6 know stages of CHO digestion o Chewing stimulates secretion of saliva and activates the salivary glands and amylase which break down CHOs into shorter polysaccharides Pancreas Liver o Produces pancreatic amylase for small intestine digestion of carbs into maltose o Monosaccharide s are converted to glucose and transported for energy 7 Hormones regulating blood glucose levels Insulin lowers Glucagon elevates Epinephrine elevates Glycemic index a system that ranks foods on a scale from 1 to Glycemic load a classification of different carbohydrates that 100 based on their effect on blood sugar levels measures their impact on the body and blood sugar also details the amount of sugar a food contains Glucose metabolic intermediate respiration o Helps stimulate brain functions o Cells use as a secondary source of energy and a o Main products of photosynthesis and fuels cellular o Ubiquitous fuel source found in most organism o Can be used by aerobic respiration and anaerobic o Key source of energy producing 3 75 Kcals of food per respiration gram increase blood acidity and Ketoacidosis can occur Ketosis fat breakdown during faster forms excess ketones Ketoacidosis when the body turns acidic due to ketones Glycogenesis diet is deficient in carbs Glucose is made from Proteins Type 1 diabetes 8 9 10 11 Type 2 o 10 of all cases o body does not produce enough insulin o causes hyperglycemia o may be autoimmune disease o 80 90 o insulin insensitivity cells become resistant to insulin o many risk factors that cause type 2 o genetics obesity and physical inactivity CHAPTER 5 1 after absorption what are the fates of triglycerides Fats and how do these happen Energy Source 9 Kcals Energy Reserve Triglycerides in fat cells o Glycerol is converted to pyruvate which is then converted to acetyl CoA for entry into TCA cycle Insulation and protection Visceral and subcutaneous fat to foods Carrier of fat soluble compounds contribute sensory qualities Chylomicrons dismantle triglycerides with Lipoprotein lipase Micelle transports lipids
View Full Document
Unlocking...