HUN1201 Exam 2 Study Guide 1 De ne hunger and appetite Which organ triggers feelings of hunger and satiation Hunger A physiologic sensation that prompts us to eat Appetite A psychological desire to consume speci c foods The Hypothalamus triggers feelings of hunger and satiation 2 What effect do different macronutrients have on hunger What type of food has the highest satiation value Proteins have the highest satiety value Proteins are highest then fats then carbs Fiber and water also affect satiety by stretching the stomach 3 De ne the processes of digestion absorption and elimination Digestion The process by which foods are broken down into their component molecules either mechanically or chemically Absorption The physiologic process by which molecules of food are taken from the gastrointestinal tract into the circulation Elimination The process by which the undigested portions of food and waste products are removed from the body 4 Know the difference between peristalsis and segmentation Peristalsis Waves of squeezing and pushing contractions that move food chyme and feces in one direction through the length of the GI tract Segmentation Rhythmic contraction of the circular muscles of the small intestine which squeezes chyme mixes it and enhances the digestion and absorption of nutrients from the chyme 5 Know the role of gastrin Gastrin A hormone secreted by stomach lining cells called G cells that stimulate gastric glands to secrete a digestive uid referred to as gastric juice 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 Parietal cells and Chief cells Gastric Juice Acidic liquid secreted within the stomach it contains hydrochloric acid pepsin and other compounds Hydrochloric Acid secreted from parietal cells keeps the interior of the stomach very acidic pH of 1 0 It kills bacteria that may have entered with food It also begins denaturing proteins for digestion Pepsinogen secreted by chief cells is an inactive enzyme that HCl converts into the active enzyme Pepsin It begins the digestion of proteins and activates many other GI enzymes Gastric Lipase secreted by chief cells begins to digest lipids 7 Know the role of bicarbonate in stomach and small intestine A base secreted by the pancreas that neutralizes acidic chyme near the surface of the stomach s lining and going into the small intestine 8 Know the enzymes produced in gastrointestinal tract mouth stomach and pancreas that facilitate the digestion of carbohydrates fats and lipids Mouth Salivary amylase begins carbohydrate breakdown Stomach Pepsin begins digestion of proteins and gastric lipase begins to break lipids apart Pancreas Pancreatic lipase digests lipids proteases digest proteins elastase digests brous proteins pancreatic amylase digests carbohydrates and cholesterol esterase digests cholesterol 9 List the key hormones involved in digestion and their actions Gastrin stimulates secretion of HCl and pepsinogen stimulates gastric motility and promotes proliferation of gastric mucosal cells Secretin stimulates secretion of pancreatic bicarbonate and decreases gastric motility Cholecystokinin CCK stimulates secretion of pancreatic digestive enzymes stimulates gallbladder contraction and slows gastric emptying Gastric Inhibitory Polypeptide GIP inhibits gastric acid secretion slows gastric emptying and stimulates insulin release 10 List the accessory organs that facilitate digestion and their roles Gallbladder Stores bile and secretes it into the small intestine Pancreas Manufactures holds and secretes digestive enzymes and bicarbonate Liver Largest accessory organ it produces bile and processes nutrient rich blood from the small intestine 11 De ne food intolerance and food allergy Intolerance GI discomfort caused by certain foods that is not a result of an immune system reaction Allergy An allergic reaction to food caused by a reaction of the immune system 12 List the most common types of monosaccharides and disaccharides Mono Glucose fructose galactose and ribose Di Lactose maltose and sucrose 13 What are the characteristics of glucose fructose and galactose 6 carbon atoms 12 hydrogen atoms and 6 oxygen atoms 14 What are the monosaccharides that synthesize lactose maltose and sucrose Lactose glucose galactose Maltose glucose glucose Sucrose glucose fructose stored liver 15 What is the storage form of carbohydrates in animals and where in the body is it Glycogen a polysaccharide is the storage from of glucose for animals and is stored in our muscles and liver 16 De ne lactose intolerance A disorder in which the body does not produce suf cient lactase enzyme and therefore cannot digest foods that contain lactose such as cow s milk 17 Know what stages of carbohydrate digestion occur in the mouth pancreas and Mouth Chewing stimulates secretion of saliva from salivary glands salivary amylase breaks down starch into shorter polysaccharides and maltose Stomach Salivary amylase is destroyed by acids no carbohydrate digestion occurs in the stomach Pancreas Produces digestive enzymes and bicarbonate which are released into the small intestine via the pancreatic duct 18 List all the hormones that regulate blood glucose levels Insulin glucagon epinephrin norepinephrin cortisol and growth hormone Insulin A hormone secreted by beta cells of the pancreas in response to increased blood levels of glucose that facilitates uptake of glucose by body cells Glucagon A hormone secreted by the alpha cells of the pancreas in response to decreased blood levels of glucose it stimulates the liver to convert stored glycogen into glucose which is released into the bloodstream and transported to cells for energy 19 De ne glycemic index and glycemic load Index A rating of the potential foods to raise blood glucose and insulin levels Load The amount of carbohydrate in a food multiplied by the glycemic index of the carbohydrate 20 List the role of glucose as an energy source Glucose is absorbed into the blood stream and travels to the liver where non glucose monosaccharides are converted to glucose It is used by the cells for energy converted to glycogen and stored in the liver and muscles for later use or converted to fat and stored in adipose tissue our red blood cells brain and nerve cells primarily rely on glucose 21 De ne ketosis ketoacidosis and gluconeogenesis Ketosis The process by which the breakdown of fat during fasting states results in the
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