Exam 2 Study Guide Chapter 3 1 Define hunger and appetite Which organ triggers the feelings of hunger and satiation Hunger is the physiological drive for food Appetite is the psychological desire for food The hypothalamus triggers the feelings of hunger and satiation Feeling full satiated results from signals from the stomach and a rise in blood glucose 2 What are the roles of nutrient type on hunger What type of nutrient has the highest satiety value High protein meals have the highest satiety value will feel satiated for longer High fat diets have a higher satiety value than high carbohydrate diets Bulky meals high in fiber and water distend the stomach and promote a sense of satiety 3 Define the processes of digestion absorption and elimination Digestion break it down large food molecules are broken down to smaller molecules mechanically and chemically Absorption use or keep it process of taking these products primarily through the intestinal wall Elimination remove it undigested portions of food and waste products are excreted from the body 4 Know the difference between peristalsis and segmentation Peristalsis is the muscular contractions that move food through the GI tract It is involuntary and rhythmic Pushes the contents from one area to the next Segmentation contractions squeezing and mix of enzymes with chime They are rhythmic contractions from circular muscles Haustra are segmentations in the colon that contract sluggishly to move contents 5 Know the role of gastrin Gastrin is a hormone secreted by G cells lining the stomach that stimulates the gastric glands to produce gastric acid 6 Know the two different types of cells in gastric glands What is gastric juice and what is the role of each component of the gastric juice The two cells in gastric glands Parietal Cells HCl intrinsic factor Chief Cells secrete pepsinogen and gastric lipase Gastric juice contains a Hydrochloric acid HCl denatures proteins and activates pepsin b Pepsin further breaks down proteins 1 Yielding Amino acid amino acid c Gastric lipase enzyme to digest fat d Intrinsic factor protein to allow the absorption of vitamin B12 7 Know the role of bicarbonate in stomach and small intestine Mucus layer and bicarbonate protect the stomach lining from the acid in gastric juices Bicarbonates neutralize acids pH buffer Bicarbonate s 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 as well as a functional one the digestive enzymes at work in the small intestine operate better at a higher pH less acidic 8 Know the enzymes produced in gastrointestinal tract mouth stomach and pancreas that facilitate the digestion of carbohydrates fats and lipids Salivary amylase begins CHO digestion in the mouth Gastric lipase digests lipids in the stomach Pancreatic Lipase digests lipids in the small intestine Pancreatic Amylase digests carbs in the small intestine 9 List the key hormones involved in digestion and their actions stimulates secretion of HCI and pepsinogen stimulates gastric motility and stimulates secretion of pancreatic bicarbonate which neutralizes acidic a Gastrin b Secretin promotes proliferation of gastric mucosal cells chyme and it decreases gastric motility stimulates gallbladder contraction and slows gastric emptying slows gastric emptying and stimulates insulin release d Gastric inhibitory peptide GIP c Cholecystokinin CCK stimulates secretion of pancreatic digestive enzymes stimulates insulin inhibits gastric acid secretion 10 List the accessory organs that facilitate digestion and each of their roles b Pancreas a Gallbladder stores bile produced by the liver CCK signals the gallbladder to release Manufactures holds and secretes digestive enzymes Stores enzymes in bile via common bile duct the inactive form chemicals like bile for metabolism Receives the products of digestion via the portal vein The liver is one of the most important organs in the body Synthesizes c Liver 11 Define food intolerance and food allergy Food Allergy Usually comes on suddenly Small amount of food can trigger Happens every time you eat the food Can be life threatening Food Intolerance Usually comes on gradually May only happen when you eat a lot of the food May only happen if you eat the food often Is not life threatening Chapter 4 1 List the most common types of monosaccharides and disaccharides Monosaccharides contain one molecule a Glucose fructose galactose and ribose Disaccharides contain two molecules b Lactose maltose and sucrose 2 What is common among the molecules of glucose fructose and galactose All three can be combined with Glucose to form a disaccharide See 4 3 What are the monosaccharides that comprise lactose maltose and sucrose Glucose Galactose Lactose Glucose Glucose Maltose Glucose Fructose Sucrose In what form are carbohydrates stored in animals and where are they stored Glycogen is the storage form of glucose for animals It is stored in the liver 4 5 Define lactose intolerance A lack of lactase GI symptoms gas cramping diarrhea Not to be confused with milk allergy Need alternate sources of calcium a E g soy milk fortified 6 Define the role of mouth pancreas and liver in carbohydrate digestion The mouth begins carbohydrate digestion with the enzyme salivary amylase Carbohydrate digestion does not occur in the stomach Stomach acids inactivate salivary amylase Most chemical digestion of carbohydrates occurs in the small intestine Fructose and galactose are converted to glucose by the liver Glucose circulating in the blood is our primary energy source 7 List all the hormones that regulate blood glucose levels and under which condition they will be released in the bloodstream BG Blood Glucose a cells BG glycogenesis Insulin Stimulates glucose transporters carrier proteins to help take glucose from the blood across the cell membrane Stimulates the liver to take up glucose and convert it to glycogen glycogenesis b Glucagon cells BG Stimulates the liver to convert glycogen to glucose Stimulates gluconeogenesis the production of glucose from amino acids c Epinephrine glycogenolysis glycolysis Secreted by the adrenal glands and nerve endings when blood glucose is low fight or flight d Norepinephrine e Cortisol f Growth hormone BG same as epinephrine gluconeogenesis lipolysis BG 8 Know the role of insulin and glucagon and how they regulate blood glucose
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