NUTRITION EXAM 2 Exam 2 Esophagus Swallowing Moves food from mouth stomach Epiglottis Flap like structure that prevents food from entering the trachea Covers the larynx Stomach Bolus passes the lower esophageal sphincter into the stomach If sphincter malfunctions causing reflux this causes heartburn Functions of the stomach 1 hold and mix food 2 water some fat and 20 alcohol absorbed 3 Produces gastrin pepsinogen HCL 4 Secretes gastric juice made of HCL pepsinogen Inactivates ingested proteins HCl functions 5 6 Destroys bacteria in foods 7 Dissolves dietary minerals for absorption 8 Converts pepsinogen to pepsin protein digestion active Important cells in the stomach Parietal cells Creates HCL and intrinsic factor Chief cells Creates gastric lipase Mixing bolus with stomach secretions Pyloric sphincter Controls the flow of chyme into the SI BOLUS vs CHYME bolus forms when you mix with saliva chyme is mixed with stomach secretions Small Intestine Divided into 3 sections order 1 Duodenum Jejunum 2 ileum 3 Interior made up of circular folds vili and fingerlike projections microvili 1 Increases the surface area 600 times Digestion and absorption occurs here Vili fingers are lined with Goblet cells Produce mucus Endocrine cells Produce hormones and Enterocytes Produce digestive enzymes and absorb nutrients brush border of microvilli that are covered with glycocalyx Liver Gallbladder and Pancreas Liver Produces bile Synthesizes and stores nutrients Gallbladder stores bile Pancreas Produces sodium bicarbonate digestive enzymes GI Hormones Gastrin pepsinogen release HCL and CCK pancreatic enzymes and bile release of pancreatic from the gallbladder Secretin bicarbonate Gastric Inhibitory Peptide the release of gastric juices limit Absorption in the SI 1 Passive diffusion absorbs fats minerals and water concentration gradient forces the nutrient into absorptive cells 2 Facilitated diffusion proteins to shuttle need carrier NUTRITION EXAM 2 need a carrier 3 Active absorption protein and ATP 4 Endocytosis absorption where compounds or liquids are engulfed type of active Major Sites of Absorption along GI Tract LI Na K fatty acids Vitamin K Biotin Moving Nutrients Around the Body Cardiovascular system water soluble nutrients short medium fatty acid chains are absorbed directly into blood stream and travel directly to the Liver Lymphatic system Alternate route for large molecules fat soluble vitamins some proteins Transported by lacteals to larger lymphatic vessels Large Intestine SI LI through ileocecal valve 3 sections of the large intestine Colon rectum and anus 5 sections of the colon cecum transverse colon ascending colon descending colon sigmoid colon 3 main functions 1 Houses bacterial flora Ileocecal valve prevents bacteria from migrating into SI Keeps growth of pathogenic bacteria under control Synthesizes vitamins Aid in lactose digestion Ferment fibers and starches 2 Absorbs water and electrolytes 3 Expels feces Common Digestive Problems Heartburn and GERD caused by Burning sensation or sour taste in the back of the mouth hoarseness trouble swallowing coughing gagging stomach content going back into espophagus lower esophageal sphincter malfunctions Risk factors Hiatal hernia alcohol use overweight smoking pregnancy Treatment Lifestyle changes and medication antacids H2 blockers Ulcers Very small erosion of the top layer of cells in the stomach or duodenum a Causes i H pylori heavy use of NSAID Mx b Alcohol smoking and emotional stress c Treatment avoid large doses of NSAIDSs Inflammatory Bowel Disease IBD Group of serious intestinal disease Ulcerative colitis and Chrohn s NOT the same as IBS Carbohydrates CHOs Main source of energy 4 kcals gm 45 65 AMDR Sugar starch and fiber forms Simple mono di Complex starch Monosaccharaides all 3 6 carbon configuration hexose Examples glucose fructose and galactose 5 carbon configuration pentose Examples RNA and DNA NUTRITION EXAM 2 body can make when needed Monosaccharide derivate Xylitol mannitol sorbitol Disaccharides Chemical bonding of 2 monosaccharaides Maltose alcohol Sucrose table sugar Lactose milk products People are unable to digest Oligosaccharides 3 to 10 single sugar units Raffinose 3 mono Stachyose 4 mono Found in Cabbage onions broccoli whole wheat legumes Can not be digested by human enzymes Metabolized by bacteria Polysaccharides many glucose molecules Starch Major digestible polysaccharide Storage for plants animals Storage for humans animals due to beta bonds Glycogen Fiber indigestible Starch 2 types of plant starch 1 Amylose Linear unbranched alpha 1 4 bonds 2 Amylopectin Examples potatoes beans bread branched alpha 1 4 alpha 1 6 pasta Digestive Enzymes for Starch Amylase Secreted from mouth and pancreas Digests amylose at alpha 1 4 bonds Alpha dextrinase Secreted from intestinal enzymes Digests amylopectin at alpha 1 6 What is the significance of more branches Causes glucose levels to increase bonds quickly Glycogen Liver stores for energy Muscles store for use in muscle and endurance activity Totally natural Fiber Total fiber added to foods Occurs naturally Functional fiber insoluble fiber Soluble fiber Dissolve in water not dissolved in water Insoluble Soluble Fibers Insoluble small intestine pass into large intestine Cellulose Hemicellulose Lignin only noncarb component of dietary fiber Skin of veggies whole grains seeds of fruits Soluble Pectins Gums Mucilages Oat bran jams and jellies Health Benefits of Fiber Insoluble Decreases intestinal transit time and constipation Lowers risk for disease and colon cancer Soluble Lowers cholesterol and glucose NUTRITION EXAM 2 a Heat stable can be used in Prevent gluconeogenesis Delays gastric emptying Alternative Non Nutritive Sweeteners Saccharin Sweet N Low a Not for cooking bitter taste Aspartame Equal a Contains phenylalanine Alternative Sweeteners Neotame cooking Acesulfamine K Sunette a Can be used in baking and cooking Sucralose Splenda a Can be used in cooking Tagatose Naturlose a Can be used in cooking Stevia plus sugar alcohols Truvia and PureVia Recommended Intakes of CHO RDA 130 g day Limit added sugars 45 65 of total energy needs a Recommendations i 6 of total energy intake Dietary Guidelines ii No more than 10 of kcals WHO iii UL of 25 of kcals DRIs Fiber 14g 1000cal is adequate intake a 25g for women under 50 21g d after 51 b 38 g for men under 50 30g after 51 Our CHO Intake 50 of total energy needs carbs Added sugars account for 16 of total kcals Dietary fiber