NURS 1114 The Digestive System Part B (1).ppt

NURS 1114: The Digestive System Instructor: Pamela Paynter-Armour Objectives Describe the following: Small Intestine Large Intestine Liver Gall Bladder Pancreas Discuss briefly disorders of the digest...

NURS 1114: The Digestive System Instructor: Pamela Paynter-Armour Objectives Describe the following: Small Intestine Large Intestine Liver Gall Bladder Pancreas Discuss briefly disorders of the digestive system Outline the embryonic development of the digestive system The Small Intestine Small Intestine: Gross Anatomy  Major organ of digestion and absorption  2–4 m long; from pyloric sphincter to ileocecal valve  Subdivisions 1. Duodenum (retroperitoneal) 2. Jejunum (attached posteriorly by mesentery) 3. Ileum (attached posteriorly by mesentery) (Meeking, 2010b)  Parotid gland Mouth (oral cavity) Sublingual gland Salivary Tongue Submandibular glands gland Esophagus Pharynx Stomach Pancreas Liver (Spleen) Gallbladder Transverse colon Duodenum Descending colon Small Jejunum Ascending colon intestine Ileum Cecum Large Sigmoid colon intestine Rectum Vermiform appendix Anus Anal canal  Duodenum The bile duct and main pancreatic duct Join at the hepatopancreatic ampulla Receives digestive enzymes and bile Enter the duodenum at the major duodenal papilla Are controlled by the hepatopancreatic sphincter (Meeking, 2010b) About 25cm (10 inches) long. Jejunum & Ileum Jejunum 2.5m long extends to ileum Ileum 3.6m long Joins the large intestine at the ileocecal valve (Marieb & Hoehn, 2010)  Right and left hepatic ducts of liver Cystic duct Common hepatic duct Bile duct and sphincter Accessory pancreatic duct Mucosa with folds Tail of pancreas Gallbladder Pancreas Major duodenal Jejunum papilla Main pancreatic duct Hepatopancreatic and sphincter ampulla and sphincter Duodenum Head of pancreas The Duodenum and Related Organs  Structural Modifications Increase surface area of proximal part for nutrient absorption Circular folds (plicae circulares) Villi Microvilli (Meeking, 2010b) Structural Modifications Circular folds in mucosa and submucosa Permanent (~1 cm deep) Force chyme to slowly spiral through lumen (Meeking, 2010b)  Vein carrying blood to hepatic portal vessel Muscle layers Lumen Circular folds Villi (a)  Structural Modifications Villi Motilefingerlike extensions (~1 mm high) of the mucosa Villus epithelium Simple columnar absorptive cells (enterocytes) Mucus-secreting goblet cells (Meeking, 2010b) Structural Modifications Microvilli Projections (brush border) of absorptive cells Bearbrush border enzymes (Meeking, 2010b)  Intestinal Crypts Intestinal crypt epithelium- between the villi, mucosa studded with pits, that lead into glands Secretory cells that produce intestinal juice Enteroendocrine cells – Secretin & CCK Intraepithelial lymphocytes (IELs) Release cytokines that kill infected cells Paneth cells Secrete antimicrobial agents (defensins and lysozyme) Stem cells (Meeking, 2010b)  Microvilli (brush border) Absorptive cells Lacteal Goblet cell Blood Vilus capillaries Mucosa associated lymphoid tissue Enteroendocrine Intestinal crypt cells Muscularis Venule mucosae Lymphatic vessel Duodenal gland Submucosa (b) Submucosa Peyer’s patches protect distal part against bacteria Duodenal (Brunner’s) glands of the duodenum submucosa, secrete alkaline mucus (Meeking, 2010b) Intestinal Juice Secreted in response to distension or irritation of the mucosa Slightly alkaline and isotonic with blood plasma Largely water, enzyme-poor, but contains mucus Facilitates transport and absorption of nutrients (Meeking, 2010b) Digestion in the Small Intestine Mechanical digestion  Segmentation: localized contractions slosh chyme back and forth mixing it with digestive juices  Peristalsis (slow waves) of the stomach pushes chyme to the duodenum Chemical digestion: 2 L/day of secretions  Alkaline chyme due to bicarbonate from pancreas and alkaline mucus from small intestine  Enzymes produced by cells on villi  Maltase – maltose into 2 glucose molecules  Sucrase – sucrose into a glucose and fructose molecules  Lactase – lactose into a glucose and galactose molecules  Peptidases – proteins into amino acids, dipeptides, tripeptides (El Camino College, n.d.). Pancreas – Exocrine and Endocrine Gland Secretions that help digestion Sodium bicarbonate (NaHCO3) maintain pH of 7.1-8.2 Pancreatic lipase: fat-digesting Pancreatic amylase: starch-digesting Proteases: protein-digesting (made in an inactivated form) Activatedby enterokinase from small intestine Chymotrypsinogen, trypsinogen, carboxypeptidase RNAase and DNAase: nucleic-digesting (El Camino College, n.d.). Chemical Digestion: Carbohydrates Absorption: via cotransport with Na+, and facilitated diffusion Enter the capillary bed in the villi Transported to the liver via the hepatic portal vein Enzymes used: salivary amylase, pancreatic amylase, and brush border enzymes (Austin, 2004a) Chemical Digestion: Proteins Absorption: similar to carbohydrates Enzymes used: pepsin in the stomach Enzymes acting in the small intestine Pancreatic enzymes – trypsin, chymotrypsin, and carboxypeptidase Brush border enzymes – aminopeptidases, carboxypeptidases, and dipeptidases (Austin, 2004a)  Fatty Acid Absorption Absorption: Fatty acids and monoglycerides enter intestinal cells via diffusion They are combined with proteins within the cells Resulting chylomicrons are extruded They enter lacteals and are transported to the circulation via lymph (Austin, 2004a) Chemical Digestion: Fats Absorption: Glycerol and short chain fatty acids are: Absorbed into the capillary blood in villi Transported via the hepatic portal vein Enzymes/chemicals used: bile salts and pancreatic lipase (Austin, 2004a) Fatty Acid Absorption Chemical Digestion: Nucleic Acids Absorption: active transport via membrane carriers Absorbed in villi and transported to liver via hepatic portal vein Enzymes used: pancreatic ribonucleases and deoxyribonuclease in the small intestines (Austin, 2004a)  Absorption of Products of Digestion By diffusion, facilitated diffusion, osmosis and active transport Carbohydrates monosaccharides Via portal system (blood) to liver Proteins  amino acids Via portal system (blood) to liver Lipids  Short-chained fatty acids or monoglycerides  blood in villi Larger lipids coated by proteins in chlyomicrons  lacteals  lymphatics (lymph)  then blood (El Camino College, n.d.). Absorption of Products of Digestion Water and ions (salt) Primarily osmotic movement that accompanies other nutrients Vitamins Fat-soluble (A, D, E, K) absorbed with fat Water-soluble (B’s, C) with simple diffusion B12  Combines with intrinsic factor for transport through duodenum and jejunum  Finally can be absorbed by active transport in ileum (El Camino College, n.d.). Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings (Hendon, 2008) Copyright © 2008 Pearson Education, Inc., publishing as Benjamin Cummings (Hendon, 2008)  Foodstuff Enzyme(s) and Source Site of Action Nucleic Acids Pancreatic ribonuclease and Small Intestine deoxyribonuclease Brush border enzymes Nucleosidases and Small Intestine phosphatases Pentose sugar, N-containing bases, Phosphate ions The Large Intestine  Large Intestine  Larger in diameter, but shorter than the small intestine  Frames the internal abdomen (Cook, 2003)  Functions of the Large Intestine  Absorption of water  Eliminates indigestible food from the body as feces  Does not participate in digestion of food  Goblet cells produce mucus to act as a Structures of the Large Intestine  Cecum – saclike first part of the large intestine  Appendix  Accumulation of lymphatic tissue that sometimes becomes inflamed (appendicitis)  Hangs from the cecum (Cook, 2003)  Structures of the Large Intestine  Colon  Ascending  Transverse  Descending  S-shaped sigmoidal  Rectum  Anus – external body opening- lined with stratified squamous epithelium (Cook, 2003) Modifications to the Muscularis Externa in the Large Intestine  Smooth muscle is reduced to three bands (teniae coli)  Muscle bands have some degree of tone  Walls are formed into pocketlike sacs called haustra (Cook, 2003)  Epiploic appendages Fat-filled pouches of visceral peritoneum The Large Intestine Digested residue contains few nutrients Small amount of digestion by bacteria Main functions Absorb water and electrolytes Mass peristaltic movements force feces toward the rectum (Hendon, 2008) Gross Anatomy of Large Intestine Gross Anatomy of Large Intestine Vessels and Nerves of the Large Intestine First half of large intestine Arterial supply - superior mesenteric artery Innervation Sympathetic innervation – superior mesenteric and celiac ganglia Parasympathetic innervation – vagus nerve (Hendon, 2008)  Vessels and Nerves of the Large Intestine Distal half of large intestine Arterial supply - inferior mesenteric artery Innervation Sympathetic innervation – inferior mesenteric and hypogastric plexuses Parasympathetic innervation – pelvic splanchnic nerves (Hendon, 2008) Defecation Reflex Microscopic Anatomy of Large Intestine Villi are absent Contains numerous goblet cells Intestinal crypts – simple tubular glands Lined with simple columnar epithelial tissue Epithelium changes at anal canal Becomes stratified squamous epithelium (Hendon, 2008) Food Breakdown and Absorption in the Large Intestine  No digestive enzymes are produced  Resident bacteria digest remaining nutrients  Produce some vitamin K and B  Release gases  Water and vitamins K and B are absorbed  Remaining materials are eliminated via feces (C00k, 2003) The Liver The Liver Largest gland in the body Performs over 500 functions Digestive function Bile production Performs many metabolic functions Four lobes—right, left, caudate, and quadrate (Hendon, 2008) Visceral Surface of the Liver Liver Falciform ligament Separates the (larger) right and (smaller) left lobes Suspends liver from the diaphragm and anterior abdominal wall Round ligament (ligamentum teres) Remnant of fetal umbilical vein along free edge of falciform ligament (Meeking, 2010b) Sternum Bare area Nipple Falciform Liver ligament Left lobe of liver Right lobe of liver Round ligament Gallbladder (ligamentum (a) teres) Sternum Nipple Liver Lesser omentum Bare area (in fissure) Caudate lobe of liver Left lobe of liver Sulcus for inferior Porta hepatis vena cava containing hepatic Hepatic vein artery (left) and (cut) hepatic portal vein Bile duct (cut) (right) Right lobe of Quadrate lobe liver of liver Gallbladder Ligamentum teres (b) Liver: Associated Structures Lesser omentum anchors liver to stomach Hepatic artery and vein at the porta hepatis Bile ducts Common hepatic duct leaves the liver Cystic duct connects to gallbladder Bile duct formed by the union of the above two ducts (Meeking, 2010b)  Right and left hepatic ducts of liver Cystic duct Common hepatic duct Bile duct and sphincter Accessory pancreatic duct Mucosa with folds Tail of pancreas Gallbladder Pancreas Major duodenal Jejunum papilla Main pancreatic duct Hepatopancreatic and sphincter ampulla and sphincter Duodenum Head of pancreas Liver: Microscopic Anatomy Liver lobules Hexagonal structural and functional units Filter and process nutrient-rich blood Composed of plates of hepatocytes (liver cells) Longitudinal central vein (Meeking, 2010b) (a) Lobule (b) Central vein Connective tissue septum Liver: Microscopic Anatomy Portal triad at each corner of lobule Bile duct receives bile from bile canaliculi Portal arteriole is a branch of the hepatic artery Hepatic venule is a branch of the hepatic portal vein Liver sinusoids are leaky capillaries between hepatic plates Kupffer cells (hepatic macrophages) in liver sinusoids (Meeking, 2010b)  Interlobular veins (to hepatic vein) Central vein Sinusoids Plates of Bile canaliculi hepatocytes Bile duct (receives bile from bile canaliculi) Fenestrated lining (endothelial cells) of sinusoids Bile duct Hepatic Portal venule Portal triad macrophages Portal arteriole in sinusoid walls Portal vein (c) Liver: Microscopic Anatomy Hepatocyte functions – (functional cells of the liver) Process bloodborne nutrients Store fat-soluble vitamins Perform detoxification Produce ~900 ml bile per day (Meeking, 2010b)  Microscopic Anatomy of the Liver Some functions of hepatocytes Rough ER manufactures blood proteins Smooth ER produces bile salts, detoxifies poisons Peroxisomes detoxify poisons (alcohol) Golgi apparatus packages secretory products Mitochondria provide energy for liver processes Glycosomes store sugar Great capacity for regeneration (Hendon, 2008)  Nutrient-rich, Oxygenated blood deoxygen-ated from hepatic blood from hepatic artery portal vein Liver sinusoids Central vein Hepatic vein Inferior vena cava (El Camino College, n.d.). Right atrium of heart The Gallbladder  The Gallbladder Thin-walled muscular sac on the ventral surface of the liver Stores and concentrates bile by absorbing its water and ions Releases bile via the cystic duct, which flows into the bile duct (Meeking, 2010b) Cholecystokinin – released from enteroendocrine cells in response to fatty chyme  Bile Yellow-green, alkaline solution containing Bile salts: cholesterol derivatives that function in fat emulsification and absorption Bilirubin: pigment formed from heme Cholesterol, neutral fats, phospholipids, and electrolytes (Meeking, 2010b) Bile Enterohepatic circulation Recycles bile salts Bile salts duodenum reabsorbed from ileum hepatic portal blood liver secreted into bile (Meeking, 2010b) Regulation of Bile Release Acidic, fatty chyme causes the duodenum to release: Cholecystokinin (CCK) and secretin into the bloodstream Bile salts and secretin transported in blood stimulate the liver to produce bile Vagal stimulation causes weak contractions of the gallbladder (Austin, 2006) Regulation of Bile Release Cholecystokinin causes: The gallbladder to contract The hepatopancreatic sphincter to relax As a result, bile enters the duodenum (Austin, 2006) Regulation of Bile 4 Vagal stimulation causes weak contractions of gallbladder 3 Bile salts and secretin transported via 5 Cholecystokinin bloodstream (via bloodstream) stimulate liver causes gallbladder to produce bile to contract and more rapidly hepatopancreatic sphincter to relax; bile enters duodenum 1 Acidic, fatty chyme entering duodenum causes release of cholecystokinin Release and secretin from duodenal wall enteroendocrine cells 2 Cholecystokinin and secretin enter the bloodstream 6 Bile salts reabsorbed into blood 1 Acidic, fatty chyme entering duodenum causes release of cholecystokinin and secretin from duodenal wall enteroendocrine cells 1 Acidic, fatty chyme entering duodenum causes release of cholecystokinin and secretin from duodenal wall enteroendocrine cells 2 Cholecystokinin and secretin enter the bloodstream  3 Bile salts and secretin transported via bloodstream stimulate liver to produce bile more rapidly 1 Acidic, fatty chyme entering duodenum causes release of cholecystokinin and secretin from duodenal wall enteroendocrine cells 2 Cholecystokinin and secretin enter the bloodstream  4 Vagal stimulation causes weak contractions of gallbladder 3 Bile salts and secretin transported via bloodstream stimulate liver to produce bile more rapidly 1 Acidic, fatty chyme entering duodenum causes release of cholecystokinin and secretin from duodenal wall enteroendocrine cells 2 Cholecystokinin and secretin enter the bloodstream  4 Vagal stimulation causes weak contractions of gallbladder 3 Bile salts and secretin transported via 5 Cholecystokinin bloodstream (via bloodstream) stimulate liver causes gallbladder to produce bile to contract and more rapidly hepatopancreatic sphincter to relax; bile enters duodenum 1 Acidic, fatty chyme entering duodenum causes release of cholecystokinin and secretin from duodenal wall enteroendocrine cells 2 Cholecystokinin and secretin enter the bloodstream  4 Vagal stimulation causes weak contractions of gallbladder 3 Bile salts and secretin transported via 5 Cholecystokinin bloodstream (via bloodstream) stimulate liver causes gallbladder to produce bile to contract and more rapidly hepatopancreatic sphincter to relax; bile enters duodenum 1 Acidic, fatty chyme entering duodenum causes release of cholecystokinin and secretin from duodenal wall enteroendocrine cells 2 Cholecystokinin and secretin enter the bloodstream 6 Bile salts reabsorbed into blood The Pancreas The Pancreas Location Lies deep to the greater curvature of the stomach The head is encircled by the duodenum and the tail abuts the spleen (Austin, 2004a) The Pancreas Exocrine function Secretes pancreatic juice which breaks down all categories of foodstuff Acini (clusters of secretory cells) contain zymogen granules with digestive enzymes The pancreas also has an endocrine function – release of insulin and glucagon (Austin, 2004a) Acinus of the Pancreas Composition and Function of Pancreatic Juice Water solution of enzymes and electrolytes (primarily HCO3–) Neutralizes acid chyme Provides optimal environment for pancreatic enzymes Enzymes are released in inactive form and activated in the duodenum (Austin, 2004a) Composition and Function of Pancreatic Juice Examples include Trypsinogen is activated to trypsin Procarboxypeptidase is activated to carboxypeptidase Active enzymes secreted Amylase, lipases, and nucleases These enzymes require ions or bile for optimal activity (Austin, 2004a) Regulation of Pancreatic Secretion Secretin and CCK are released when fatty or acidic chyme enters the duodenum CCK and secretin enter the bloodstream Upon reaching the pancreas: CCK induces the secretion of enzyme- rich pancreatic juice Secretin causes secretion of bicarbonate-rich pancreatic juice Vagal stimulation also causes release of pancreatic juice (Austin, 2004a) Regulation of Pancreatic Secretio Disorders of the Digestive System Intestinal obstruction Mechanical obstructions Adhesions, tumors, or foreign objects Nonmechanical obstruction Halt in peristalsis Trauma Intestines touched during surgery (Hendon, 2008) Disorders of the Digestive System Inflammatory bowel disease Inflammation of intestinal wall Crohn’s disease Ulcerative colitis Viral hepatitis Jaundice and flu-like symptoms Major types – A, B, C, and G (Hendon, 2008)  Embryonic Development of the Digestive System Alimentary canal formed in week three Encloses tubular portion of yolk sac Vitelline duct Landmark dividing into three regions Forgut Midgut Hindgut (Hendon, 2008) Embryonic Development of the Digestive System  The Digestive System in Later Life Middle age – gallstones and ulcers Old age – activity of digestive organs decline Fewer digestive juices and enzymes produced Absorption is less efficient Dehydration of fecal mass leads to constipation Diverticulosis and cancer of digestive organs (Hendon, 2008) Name the colored organs Green: Red: Pink: Brown: Purple: Green: Yellow: ANSWER Green: Esophagus Red: Stomach Pink: Small Intestine Brown: Large Intestine Purple: Liver Green: Gall Bladder Yellow: Pancreas (Poole,Great 2009). Job! Question Most of the digestive enzymes found in the small intestine are secreted by this accessory organ. a. Liver b. Gallbladder c. Stomach d. Pancreas Answer Most of the digestive enzymes found in the small intestine are secreted by this accessory organ. a. Liver b. Gallbladder c. Stomach d. Pancreas Question The fingerlike projections of the intestinal mucosa are called: a. rugae. b. plicae circulares. c. brush borders. d. villi. Answer The fingerlike projections of the intestinal mucosa are called: a. rugae. b. plicae circulares. c. brush borders. d. villi. Question This substance secreted by the pancreas helps neutralize chyme. a. Chymotrypsin b. Bile c. Trypsin d. Bicarbonate Answer This substance secreted by the pancreas helps neutralize chyme. a. Chymotrypsin b. Bile c. Trypsin d. Bicarbonate Question Which of the following is not part of the large intestine? a. Cecum b. Appendix c. Ileum d. Sigmoid colon Answer Which of the following is not part of the large intestine? a. Cecum b. Appendix c. Ileum d. Sigmoid colon Question The pocketlike sacs of the large intestine are called: a. teniae coli. b. haustra. c. epiploic appendages. d. cecae. Answer The pocketlike sacs of the large intestine are called: a. teniae coli. b. haustra. c. epiploic appendages. d. cecae. References Austin, V. (2004a). The Digestive System. Retrieved from http://www.google.tt/url? sa=t&rct=j&q=&esrc=s&source=web&cd=1 &ved=0CCQQFjAA&url=http%3A%2F %2Ffacstaff.gpc.edu%2F~rmcdonou %2Fpowerpoints%2Fbiol_1612_lectures %2FChapter%252023%2520The %2520Digestive %2520System.ppt&ei=IXYlU_m9HYaTyQGQpI GoCQ&usg=AFQjCNEcn93juVX3tMx_mlBpNX qBol95JA References Cont’d Austin, V. (2006). The Digestive System Part B. Retrieved from http://www.google.tt/url? sa=t&rct=j&q=&esrc=s&source=web&cd=6 &ved=0CEMQFjAF&url=http%3A%2F %2Ffacweb.northseattle.edu%2Frvieira %2Fap214%2FHAP7_23- b.ppt&ei=IXYlU_m9HYaTyQGQpIGoCQ&usg =AFQjCNHTfapZUf5AQ_fj0hEQT8YOJWtHxg References Cont’d Community College of Rhode Island. (n.d.). Digestive System. Retrieved from http://www.google.tt/url? sa=t&rct=j&q=&esrc=s&source=web&cd=6 &ved=0CD8QFjAF&url=http%3A%2F %2Ffaculty.ccri.edu%2Fjgluck%2FDigestion- FINISHED.ppt&ei=KmslU86yNIKCyAGF4oG 4CA&usg=AFQjCNFle01jKCGOQOB3oGYmiX 1RRkBYEQ References Cont’d Cook, J., L. (2003). The Digestive System and Body Metabolism. Retrieved from http://www.google.tt/url? sa=t&rct=j&q=&esrc=s&source=web&cd=1 &ved=0CCEQFjAA&url=http%3A%2F %2Fwww.mtnbrook.k12.al.us%2FImages %2FTeachers %2F439%2FCh14%2520Lect.ppt&ei=128lU7 muCOWuyQGO6oC4CA&usg=AFQjCNH0QkY LuoMq9s_NQf_gE00YLAAVqw References Cont’d El Camino College. (n.d.). The Digestive System. Retrieved from http://www.google.tt/url? sa=t&rct=j&q=&esrc=s&source=web&cd=2 &ved=0CCcQFjAB&url=http%3A%2F %2Fwww.elcamino.edu%2Ffaculty%2Favalle %2Fdocuments %2FSpring2013%2Fch23_Digestive.ppt&ei=1 28lU7muCOWuyQGO6oC4CA&usg=AFQjCNF _FIyFeu30DdQSd0YbzOyiGbliBA References Cont’d Hendon, L.(2008). The Digestive System. Retrieved from http://www.google.tt/url? sa=t&rct=j&q=&esrc=s&source=web&cd=8 &ved=0CEcQFjAH&url=http%3A%2F %2Flpc1.laspositascollege.edu%2Flpc %2Fbhinck %2FAnat1%2F22_01LectureOutline %2F22_01LectureOutlines %2FHA5_MM_ch22_1.ppt&ei=128lU7muCOW uyQGO6oC4CA&usg=AFQjCNGffXRxpJ4ngCC HkE7c74i8khfy1Q References Cont’d Meeking, J. (2010). The Digestive System, Part A. Retrieved from http://www.google.tt/url? sa=t&rct=j&q=&esrc=s&source=web&cd=3 &ved=0CCsQFjAC&url=http%3A%2F %2Fwww.hccfl.edu%2Fmedia %2F379423%2Fch_23_lecture_outline_a.ppt& ei=BHQlU9neMOm2yAGz9YCABg&usg=AFQj CNGgyr8C1x1HToMckB8UkEN_36mcvA References Cont’d Meeking, J. (2010). The Digestive System, Part B. Retrieved from http://www.google.tt/url? sa=t&rct=j&q=&esrc=s&source=web&cd=1 &ved=0CCEQFjAA&url=http%3A%2F %2Flibrary.sgc.peachnet.edu%2Fsundram %2F2211%2Fch_23_lecture_outline_b.ppt&ei =BHQlU9neMOm2yAGz9YCABg&usg=AFQjC NFXotQzp_PwLkH1eBfe2a93g05I6w References Cont’d Poole, L. (2009). The Human Digestive System. Retrieved from http://www.google.tt/url? sa=t&rct=j&q=&esrc=s&source=web&cd=2 &ved=0CCYQFjAB&url=http%3A%2F %2Frosedale11collegebiology.wikispaces.com %2Ffile%2Fview%2F09-Digestive %2Bsystem.ppt&ei=KmslU86yNIKCyAGF4oG 4CA&usg=AFQjCNH1UfbjwXYkPBkAczeS7tB arxlQRQ&bvm=bv.62922401,d.aWc References Cont’d Quiz Show. (n.d.). The Digestive System. Retrieved from http://www.google.tt/url? sa=t&rct=j&q=&esrc=s&source=web&cd=5 &ved=0CDcQFjAE&url=http%3A%2F %2Fwww.wcc.hawaii.edu%2Ffacstaff %2Fmiliefsky-m%2FJeopardy%2FMarieb %2520Jeopardy %2Fch_23_quiz_show_game.ppt&ei=13clU9- WK5CFyQGZ0IDYCQ&usg=AFQjCNH0IuZ67 wp1NFbyOGQxxZ8ZedpVuw