Exam 2 Study Guide 1 Define hunger and appetite Which organ triggers feelings of hunger and satiation Hunger physiological need for food Appetite wanting a certain food but not necessarily needing it 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 satiation value High fat diets have a higher satiety value than high carb diets 3 Define the processes of digestion absorption and elimination Digestion is where large food molecules are broken down to smaller molecules mechanically and chemically Absorption is the process of absorbing these products through the intestinal wall Elimination is when the undigested products are removed from the body 4 Know the difference between peristalsis and segmentation Peristalsis is when the muscles of the GI tract push its contents from one area to the next esophagus too Segmentation is the mixing of chyme and enhances its contact with digestive enzymes and enterocytes 5 Know the role of gastrin Gastrin is a hormone secreted by the stomach lining cells that stimulates the gastric glands to produce 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 The two different cells in the gastric glands are parietal and chief cells Parietal cells secrete HCI and intrinsic factor Chief cells secrete pepsinogen and gastric lipase Gastric juice contains hydrochloric acid HCI which denatures proteins and activates pepsin Pepsin is an enzyme that digests protein Gastric lipase is an enzyme that digests fat Intrinsic factor is a protein to cleave vitamin B12 for absorption in the GI tract 7 Know the role of bicarbonate in stomach and small intestine Bicarbonate neutralizes the acid in the stomach HCI 8 Know the enzymes produced in gastrointestinal tract mouth stomach and pancreas that facilitate the digestion of carbohydrates fats and lipids A Carbohydrates Salivary amylase begins digestion in the mouth Carbohydrate digestion does not occur in the stomach Stomach acids inactivate salivary amylase Most digestion occurs in the small intestine Pancreatic amylase digests carbohydrates to maltose Additional enzymes in the microvilli digest disaccharides into monosaccharides Maltase Sucrase and Lactase B Lipids Gastric lipase digests fat Digestion occurs in the small intestine Cholecystokinin CCK and secretin gallbladder contractions release bile Bile emulsifies fat into small droplets Pancreatic enzymes pancreatic lipase break fat into two fatty acids and a monoglyceride 9 List the key hormones involved in digestion and their actions Hormone Gastrin Production Site Target Organ Actions Stomach Stomach Stimulates the secretion of HCI and pepsinogen inactive form of pepsin Stimulates gastric motility Promotes proliferation of gastric mucosal cells Stimulates the secretion of pancreatic bicarbonate which neutralizes acidic chyme Decreases gastric Secretin Small Intestine duodenum Pancreas Stomach Cholecystokinin CCK Small intestine duodenum and jejunum Pancreas Gallbladder Stomach Gastric Inhibitory Peptide GIP Small Intestine Stomach Pancreas motility Stimulates secretion of pancreatic digestive enzymes Stimulates gallbladder contraction Slows gastric emptying Inhibits gastric acid secretion and slows gastric emptying Stimulates insulin release 10 List the accessory organs that facilitate digestion and their roles Organ Gallbladder Pancreas Actions Stores bile which is produced by the liver CCK signals gallbladder to release bile Bile emulsifies lipids helping digestion of fat Manufactures holds and secretes digestive enzymes Stores enzymes in the inactive form Pancreatic amylase carbs Pancreatic lipase fats Protease proteins Insulin and glucagon hormones are produced to regulate blood glucose Bicarbonate is used to neutralize Chyme Liver Synthesizes chemicals for metabolism Bile for emulsification of fats Receives products via the portal vein Releases glucose from glycogen storage Stores vitamin D and vitamin A Manufactures blood proteins Filters the blood removes wastes and toxins 11 Define food intolerance and food allergy Food intolerance is a detrimental reaction often delayed to a food beverage food additive or compound found in foods that produces symptoms in one or more body organs and systems Food allergy abnormal immune response to food 12 List the most common types of monosaccharides and disaccharides Monosaccharides Glucose fructose and galactose Disaccharides Lactose maltose and sucrose 13 What are the characteristics of glucose fructose and galactose Glucose plants Fructose fruits Galactose dairy 14 What are the monosaccharides that synthesize lactose maltose and sucrose Galactose Glucose Lactose Glucose Glucose Maltose Glucose Fructose Sucrose 15 What is the storage form of carbohydrates in animals and where in the body is it stored Glycogen and it is stored in the liver and muscles 16 Define lactose intolerance Lactose intolerance occurs when a person has an insufficient enzyme of lactase that has trouble digesting the lactose containing foods Symptoms include gas cramping and diarrhea 17 Know what stages of carbohydrate digestion occur in the mouth pancreas and liver Carbohydrate digestion begins in the mouth with salivary amylase Salivary amylase breaks down carbohydrates into maltose Carbohydrates do not digest in the stomach because the acid inactivates salivary amylase Most chemical digestion occurs in the small intestine Pancreatic amylase digests carbohydrates to maltose In the small intestine microvillus digests disaccharides into monosaccharides All monosaccharides are converted into glucose by the liver Glucose circulating in the blood is our primary energy source Excess glucose is stored as glycogen in the liver and muscles 18 List all the hormones that regulate blood glucose levels Insulin Glucagon Epinephrine Norepinephrine Cortisol Growth hormone 19 Define glycemic index and glycemic load Glycemic Index a food s potential to raise blood glucose food s with a high glycemic index cause a sudden surge in blood glucose not 100 proven Glycemic Load determines the effect of a food on a person s glucose response 20 List the role of glucose as an energy source Red blood cells only use glucose for energy Carbohydrates and fats supply energy for daily activities Glucose is important for energy during exercise
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