Digestive System and Metabolism Practice Exam 1. The walls of the GI tract are composed of ______ layers of tissue. A. two B. three C. four D. five 2. All of the following are classified as accessory organs of the digestive system except: A. tongue B. mouth C. liver D. pancreas 3. Which of the following organs has a mucosa layer composed of stratified squamous epithelium that resists abrasion? A. esophagus B. stomach C. small intestine D. large intestine 4. The flap of tissue suspended from the midpoint of the posterior border of the soft palate is the: A. fauces B. frenulum C. uvula D. gingiva 5. The type of cell designed for absorption and secretion found throughout much of the GI tract is: A. simple columnar epithelium B. stratified squamous epithelium C. simple squamous epithelium D. pseudostratified epithelium 6. After leaving the stomach, food (chyme) enters the: A. large intestine B. small intestine C. esophagus D. rectum 7. An incision into the wall of the GI tract would cut, in order, from outside to inside: A. mucosa, submucosa, muscularis, serosa B. serosa, submucosa, muscularis, mucosa C. serosa, muscularis, submucosa, mucosa D. muscularis, submucosa, mucosa, serosa 8. Which of the following organs has a mucosal layer that is composed of columnar epithelium with a brush border of microvilli to enhance absorption? A. esophagus B. large intestine C. small intestine D. stomach 9. The more common term for deglutition is: A. chewing B. swallowing C. mechanical digestion D. vomiting 10. Which of the following salivary glands produces only a mucous type of saliva? A. sublinguals B. parotids C. submandibulars D. both a and b 11. Which of the following structures controls the opening of the stomach into the small intestine? A. fundus B. cardiac sphincter C. pyloric sphincter D. body 12. In the stomach, hydrochloric acid is secreted by the: A. chief cells B. parietal cells C. lymph nodules D. both a and b 13. Hydrochloric acid is released from cells in the: A. stomach B. pancreas C. small intestine D. large intestine E. all of the above 14. The chief cells in the stomach secrete: A. gastrin B. mucus C. intrinsic factor D. digestive enzymes 15. Which of the following is not associated with the large intestine? A. pyloric sphincter B. cecum C. appendix D. transverse colon 16. The longest portion of the small intestine is the: A. duodenum B. ileum C. jejunum D. colon 17. The contents of the stomach are emptied into the: A. duodenum B. ileum C. jejunum D. cecum 18. Which of the following is not an anatomical part of the small intestine? A. duodenum B. cecum C. ileum D. jejunum 19. The part of the colon that lies in the vertical position, on the left side of the abdomen, extending from a point below the stomach and spleen to the level of the iliac crest is the: A. ascending colon B. transverse colon C. descending colon D. sigmoid colon 20. The proper anatomical order for the divisions of the colon is: A. descending, transverse, sigmoid, ascending B. ascending, transverse, sigmoid, descending C. sigmoid, ascending, transverse, descending D. ascending, transverse, descending, sigmoid 21. The brush border of the intestinal mucosa consists of: A. hair cells B. villi C. cilia D. microvilli 22. Which of the following is not associated with the large intestine? A. cecum B. sigmoid colon C. vermiform appendix D. pyloric sphincter 23. Phagocytic cells lining liver sinusoids are called: A. chief cells B. alpha cells C. Kupffer cells D. hepatic cells 24. Bile salts aid in the absorption of: A. fats B. proteins C. carbohydrates D. calcium, magnesium, and certain other minerals 25. The most essential part of bile is: A. bile salts B. bile pigments C. cholesterol D. bilirubin 26. Bile is secreted by: A. parietal cells B. crypts of Lieberkuhn C. Kupffer cells D. hepatic cells 27. Which of the following is not a lobe of the liver? A. right lobe B. medial lobe C. left lobe D. caudate lobe E. quadrate lobe 28. Which of the following is not a function of the liver? A. detoxification B. secretion of insulin C. storage of iron and vitamins D. carbohydrate metabolism 29. Which of the following organs is classified as a dual gland (both exocrine and endocrine)? A. gallbladder B. liver C. pancreas D. both a and c 30. The function of the digestive system is to alter the chemical and physical composition of food so that it can be absorbed and used by body cells. A. True B. False 31. The alimentary canal has two openings to the exterior of the body. A. True B. False 32. The lining of the digestive system consists of three layers. A. True B. False 33. The pancreas is an essential organ of the digestive system. A. True B. False 34. After food is digested it enters the alimentary canal. A. True B. False 35. The walls of the stomach and the small intestine have three layers of muscle tissue. A. True B. False 36. The esophagus is anterior to the trachea. A. True B. False 37. The lesser curvature is on the upper right border of the stomach. A. True B. False 38. The pyloric sphincter is located in the fundus portion of the stomach. A. True B. False 39. The parietal cells secrete hydrochloric acid. A. True B. False 40. The chief cells, located in the stomach, secrete hydrochloric acid and are also thought to produce intrinsic factor. A. True B. False 41. The gastric glands in the small intestine secrete enzymes and hydrochloric acid. A. True B. False 42. The presence of villi and microvilli increase the surface area of the large intestine. A. True B. False 43. The vermiform appendix is a wormlike projection extending from the cecum. A. True B. False 44. Bile is released from the gallbladder into the stomach to aid in the digestive process. A. True B. False 45. Cholesterol is a component of bile. A. True B. False 46. Glucagon and insulin assist the GI tract in the digestive process. A. True B. False 47. Match the following descriptions with the salivary glands. A. parotid glands B. submandibular glands C. sublingual glands D. more than one of the above glands _____ largest of the paired salivary glands ____ located in front and below the ears _____ smallest of the salivary glands _____ found below the angle of the lower jaw _____ secretes enzymes but no mucus _____ produces a mucous type of saliva _____ produces both enzymes and mucus 48. Match the functions with the appropriate organ of the digestive system. A. stomach B. liver C. gallbladder D. pancreas _____ concentrates bile five- to tenfold _____ secretes intrinsic factor _____ beta cells secrete insulin _____ secretes about a pint of bile a day _____ produces the hormone gastrin _____ stores bile that enters by way of the hepatic and cystic ducts _____ acinar units secrete digestive enzymes _____carries on a limited amount of absorption of some water, alcohol, and certain drugs _____ cells in this organ store iron and vitamins A, B12 , and D _____ cells of this organ detoxify various substances 49. List the tissue layers that make up the alimentary canal, beginning with the interior layer. 50. The pharynx functions in two systems. Name the systems. 51. What two structures are joined by the cardiac sphincter? 52. Where in the GI tract are villi and microvilli located? What purpose do they serve? 53. Ducts from two organs join to form the common bile duct. Name the organs and the ducts from each. 54. Liver cells detoxify substances. Explain what happens to the substances in the process of detoxification. 55. What is the function of the gallbladder? 56. The myenteric plexus is found in this layer of the GI wall. A. mucosa B. submucosa C. muscularis D. serosa 57. Which of the following statements is true? A. The cystic duct and the pancreatic duct join to form the common bile duct B. The common bile duct is formed by the cystic duct from the liver and the hepatic duct from the gallbladder C. The pancreatic duct and the hepatic duct join to form the common bile duct D. None of the above are true 58. Which of the following is not a division of the stomach? A. rugae B. body C. pylorus D. fundus 59. Which of the following is not a function of the liver? A. detoxification of various substances in the blood B. the production of glucagon C. store iron D. produce plasma proteins 60. Which of the following is not a function of the liver? A. stores vitamin A B. carries on numerous steps in the metabolism of fats, carbohydrates and proteins C. secretes bile D. stores bile 61. Which of the following is not a part of the large intestine? A. transverse mesocolon B. sigmoid colon C. ascending colon D. cecum 62. Which of the following is not a function of the stomach? A. secretes gastric juices B. secretes intrinsic factor C. produces the hormone gastrin D. begins deglutition 63. Both the chemical composition and the physical state need modification so food can be absorbed. A. True B. False 64. The submucosal plexus is a group of parasympathetic nerves found in the submucosa A. True B. False 65. The muscularis layer of the wall of the GI tract consists of a single layer of circular muscle. A. True B. False 66. One of the functions of the intrinsic factor of the stomach is to protect vitamin A from damage. A. True B. False 67. Goblet cells are mucus-secreting cells found in the crypts of the small intestine. A. True B. False 68. In the wall of the small intestine the longitudinal muscles are grouped into tape-like strips called haustra. A. True B. False 69. In the wall of the large intestine, the longitudinal muscles are grouped into tape-like strips called taeniae coli. A. True B. False 70. The peritoneum that covers the organs is called the visceral layer. A. True B. False 71. Give the complete definition of digestion. 72. Which of the following is not one of the openings that must be blocked when food moves from the pharynx into the esophagus? A. oropharynx B. nasopharynx C. larynx D. mouth 73. Which of the processes of mechanical digestion occur in the esophagus? A. deglutition B. peristalsis C. churning D. both a and b 74. Which step of deglutition is under voluntary control? A. oral stage B. pharyngeal stage C. esophageal stage 75. The purpose of peristalsis is to: A. break apart chunks of food and mix it in digestive juices B. propel food forward along the GI tract C. absorb food D. enable swallowing 76. Polysaccharides are hydrolyzed to disaccharides by enzymes known as: A. lipase B. proteases C. maltase D. amylase 77. The final product of carbohydrate digestion is a: A. disaccharide B. monosaccharide C. polysaccharide D. fatty acid 78. The major final product that results from the digestion of carbohydrates is: A. glucose B. sucrose C. lactose D. maltose 79. The process of fat emulsification consists of: A. chemically breaking down fat molecules B. the secretion of digestive juices for fat digestion C. absorption of fats D. breaking fats into small droplets 80. The enzyme pepsin begins the digestion of: A. carbohydrate B. protein C. fat 81. An end product of fat digestion is: A. glycerol B. glucose C. glycogen D. galactose 82. The hormone that stimulates the release of bicarbonate substance from the pancreas is: A. enterogastrone B. secretin C. gastrin D. cholecystokinin 83. The major site for the absorption of the end products of digestion is the: A. stomach B. small intestine C. cecum D. large intestine 84. The intestinal hormone, cholecystokinin: A. causes the pancreas to increase exocrine secretions high in enzyme content B. opposes the influence of gastrin on gastric parietal cells C. stimulates the contraction of the gallbladder D. all of the above 85. Bicarbonates are useful in the GI tract to: A. neutralize hydrochloric acid B. break down fats C. activate secretin D. activate pepsin 86. The hormone that stimulates the gallbladder to release bile is: A. enterogastrone B. secretin C. enterocrinin D. cholecystokinin-pancreozymin 87. The hormone thought to be a messenger causing release of digestive enzymes from the intestinal mucosa is: A. vasoactive intestinal peptide B. enterogastrone C. secretin D. cholecystokinin 88. Chylomicrons are formed for the transport of: A. amino acids B. fats C. glucose D. vitamins 89. Which blood vessel carries absorbed food from the GI tract to the liver? A. hepatic artery B. hepatic vein C. portal vein D. renal artery 90. The bolus of food is formed during the pharyngeal stage of deglutition. A. True B. False 91. Peristalsis is a back-and-forth action that breaks apart chunks of food and mixes in digestive juices. A. True B. False 92. Pepsin is inactive in the presence of hydrochloric acid. A. True B. False 93. Amino acids are the end products of protein digestion. A. True B. False 94. Bile catalyzes the breakdown of fats. A. True B. False 95. The stimulation of gastric juice secretion occurs in five phases controlled by reflex and chemical mechanisms. A. True B. False 96. Secretin causes the production of pancreatic fluid high in enzyme content but low in bicarbonate. A. True B. False 97. The enterogastric reflex stimulates gastric motility as food enters the duodenum. A. True B. False 98. Salivary glands are stimulated only by olfactory and visual stimuli. A. True B. False 99. The only food that can be digested by gastric juice is protein. A. True B. False 100. One of the functions of cholecystokinin is to enhance the influence of gastrin on gastric parietal cells. A. True B. False 101. Chylomicrons are composed mainly of neutral fats and some cholesterol covered by a delicate protein envelope. A. Tru B. False 102. Vitamins A, D, E, and K depend on bile salts for their absorption. A. True B. False 103. Match the primary mechanisms of the digestive system with their correct definitions. A. motility B. ingestion C. elimination D. secretion E. digestion F. absorption _____release of digestive juices; release of endocrine hormones that regulate digestion or metabolism of nutrients _____excretion of the residues of the digestive process (feces) from the rectum, through the anus; defecation _____movement by the muscular components of the digestive tube, including processes of mechanical digestion; examples include peristalsis and segmentation _____movement of digested nutrients through the GI mucosa and into the internal environment _____a group of processes that break complex nutrients into simpler ones, thus facilitating their absorption (includes both mechanical and chemical processes) ______food into the mouth, starting it on its journey through the digestive tract 104. Match the phases of gastric secretion with the correct statement or definition. A. cephalic phase B. gastric phase C. intestinal phase _____phase of gastric secretion that responds to taste, smell, thoughts of food, and sensations of chewing and swallowing _____phase of gastric secretions that is controlled by the entrance of acidic chyme into the duodenum _____phase of gastric secretion that is initiated by the presence of food in the stomach 105. Match the digestive juices and enzymes with the descriptions. A. amylase B. bile C. lactase D. maltase E. pepsin F. peptidase G. sucrase H. trypsin _____ enzyme that works on starch _____ converts maltose to glucose _____ enzyme found in the mouth _____ major enzyme in stomach associated with protein breakdown _____ enzyme that works on milk sugars _____ enzyme that works on cane sugars _____ hydrochloric acid activates this enzyme _____ pancreatic enzyme that works on proteins _____enzyme from lining of small intestine that produces the end products of amino acids ____ enzyme that works on malt sugars _____ stimulates secretion of gastric juice rich in pepsin and hydrochloric acid 106. Match the digestive hormones with their actions. A. secretin B. cholecystokinin-pancreozymin (CCK) C. gastrin D. gastric inhibitory peptide (GIP) _____inhibits gastric secretion; stimulates secretion of pancreatic juice low in enzymes and high in alkalinity; stimulates ejection of bile by the gallbladder _____stimulates ejection of bile from the gallbladder and secretion of pancreatic juice high in enzymes; opposes the action of gastrin, reducing the pH of gastric juice _____ inhibits gastric secretion and motility 107. What are the three purposes of mechanical digestion? 108. What happens in the chemical process of hydrolysis? 109. What suffix is frequently used to denote an enzyme? 110. List the six kinds of chemical substances that we eat. 111. What three substances that we ingest have to be chemically digested? 112. The following structures all are involved in peristalsis except the A. esophagus B. small intestine C. pharynx D. stomach 113. The enzyme amylase functions best in A. an acid pH B. a base pH C. a neutral pH D. both A and B 114. The process of emulsification is important in the digestion of A. proteins B. fats C. polysaccharides D. disaccharides 115. Saliva contains all of the following substances except A. amylase B. lipase C. intrinsic factor D. mucus 116. Pancreatic juice contains all the following substances except A. amylase B. trypsinogen C. enterokinase D. lypase 117. Bile contains all the following substances except A. bile salts B. lecithin C. amylase D. bilirubin 118. Pancreatic juice contains all the following substances except A. chymotrypsin B. nucleases C. amylase D. pepsinogen 119. The primary function of the digestive system is to bring essential nutrients into the internal environment so that they are available to the cells of the body. A. True B. False 120. Mastication is another word for chewing. A. True B. False 121. In deglutition, the tongue closes off the nasopharynx. A. True B. False 122. In deglutition, food is denied entry to the larynx by muscle action that causes the epiglottis to block this opening A. True B. False 123. The involuntary part of swallowing is regulated by the deglutition center of the medulla. A. True B. False 124. The stomach releases gastric inhibitory peptide to slow down peristalsis in the duodenum. A. True B. False 125. Intestinal motility includes both peristaltic contractions and segmentation. A. True B. False 127. The reason that enzymes are pH sensitive is that differences in the hydrogen ion concentration can effect the shape of the protein molecule. A. True B. False 128. One important role of the salivary glands is the production of mucus, because they are the only glands that produce it. A. True B. False 129. Hydrochloric acid converts pepsinogen into pepsin. A. True B. False 130. Enterokinase converts trypsin into tyrpsinogen. A. True B. False 131. Enterokinase is converted to trypsinogen by trypsin. A. True B. False 132. The hormones GIP, secretin, and CCK are secreted by the exocrine glands of the duodenum. A. True B. False 133. Chylomicrons are formed in the epithelial cells lining the small intestine. A. True B. False 134. Chylomicrons are absorbed by the blood vessels in the villi of the small intestine. A. True B. False 135. The nutrients absorbed by the lacteals enter the blood by being dumped into the subclavian veins. A. True B. False 136. The only voluntary activity of the GI tract is swallowing. A. True B. False 137. Which of the following is true of metabolism? A. It involves both a physical and a chemical breakdown of foods. B. It occurs both inside and outside of cells. C. It involves synthesis and decomposition. D. Energy is released from the process of anabolism and catabolism 138. Which of the following is not true of ATP? A. It is a high energy substance. B. It is formed by the synthesis of ADP and phosphate. C. It releases energy when spilt. D. It cannot be recycled after it is broken down. 139. Which of the following is true of catabolism? A. It is a synthesis process involving the release of energy. B. It is a decomposition process involving the release of energy. C. It is a synthesis process involving the use of energy. D. It is a decomposition process involving the use of energy. 140. Which of the following is true of energy released by the breakdown of food substances? A. It is used to synthesize ATP. B. It is used to decompose ATP. C. It is changed to heat energy and used for cell functioning. D. It is used directly for cell functioning. 141. The preferred energy fuel of the body is: A. fructose B. glucose C. amino acids D. fatty acids 142. The process of splitting glycogen is called: A. glycogenesis B. glycogenolysis C. gluconeogenesis 143. Which of the following is not true of glycolysis? A. It occurs in the mitochondria. B. Glucose is split into two pyruvic acid molecules. C. It is an anaerobic process. D. A specific enzyme catalyzes each step of the reaction. 144. The Krebs cycle takes place in the: A. ribosome B. cytoplasm C. mitochondria D. Golgi apparatus 145. Which of the following names is not a term used for the aerobic breakdown of food substances? A. citric acid cycle B. pyruvic acid cycle C. Krebs cycle D. tricarboxylic acid cycle 146. An increased blood sugar level stimulates which of the following to occur? A. glycogenolysis B. glycogenesis C. gluconeogenesis D. glycolysis 147. The process of gluconeogenesis occurs in the: A. live B. skeletal muscle C. brain D. all of the above 148. The conversion of proteins to glucose is an example of: A. glycogenesis B. gluconeogenesis C. glycogenolysis D. glycolysis 149. Deamination, the splitting off of an amino group from an amino acid molecule to form a molecule of ammonia and one of keto acid, is the first step in: A. protein catabolism B. protein anabolism C. protein metabolism 150. A hormone that stimulates the conversion of proteins to glucose is: A. ACTH B. growth hormone C. thyroid hormone D. TSH 151. Which of the following hormones is not hyperglycemic? A. glucagon B. glucocorticoids C. insulin D. epinephrine 152. Excess glucose and amino acids are converted to: A. fatty acids B. glycerol C. triglycerides D. phospholipids 153. The most common lipids in the diet are: A. phospholipids B. cholesterol C. triglycerides D. prostaglandins 154. All of the following hormones control lipid metabolism except: A. ACTH B. glucocorticoids C. epinephrine D. insulin 155. Which of the following stimulates protein synthesis? A. testosterone B. estrogen C. glucagon D. ACTH 156. Metabolism requires the use of enzymes to catalyze chemical reactions. A. True B. False 157. Oxidation phosphorylation refers to the breakdown of ATP into ADP, phosphate, and energy in the presence of oxygen. A. True B. False 158. Oxidative phosphorylation refers to the joining of a phosphate group to ADP to form ATP. A. True B. False 159. All cells have the ability to store glycogen. A. True B. False 160. In the electron transport system, electrons moving down the carrier chain release bursts of energy used to pump neutrons into the compartment between the inner and outer membranes of the mitochondrion. A. True B. False 161. The conversion of proteins to glucose is an example of gluconeogenesis. A. True B. False 162. Whereas insulin tends to decrease the blood glucose level, glucagon tends to increase it. A. True B. False 163. Both epinephrine and glucagon accelerate liver and muscle glycogenolysis. A. True B. False 164. Hormones that cause the blood level of glucose to rise are called hypoglycemic. A. True B. False 165. Glucagon accelerates glycogenolysis in both liver and muscle cells. A. True B. False 166. Insulin comes from the beta cells of the pancreas. A. True B. False 167. Both epinephrine and glucagon accelerate liver and muscle glycogenolysis. A. True B. False 168. Lipoproteins are primarily produced in the liver. A. True B. False 169. Fatty acids are converted to ketone bodies in the liver. A. True B. False 170. Lipids are transported in blood as chylomicrons, lipoproteins, and free fatty acids. A. True B. False 171. Deamination, a process that occurs in the liver, is the first step in the catabolism of proteins. A. True B. False 172. Body weight increases when energy input is less than energy output. A. True B. False 173. It is correct to say that ATP functions as the universal biological currency. A. True B. False 174. There are three high energy phosphate bonds in adenosine triphosphate. A. True B. False 175. Match the following hormones with their effect on the blood glucose level. A. lower blood glucose level B. raise blood glucose level C. lower or raise blood glucose level _____ glucagon _____ ACTH, glucocorticoids ____ insulin _____ growth hormone ____ TSH, thyroid hormone ____ epinephrine 176. Match these terms with the correct statement or definition. A. anabolism B. catabolism C. metabolism D. nutrition _____energy-requiring processes by which small molecules are joined to form larger molecules _____energy-releasing process by which large molecules are broken down into smaller molecules _____ anabolism and catabolism combined _____ process in which ATPs and heat are produced _____the use the body makes of foods after they have been digested, absorbed, and circulated to cells _____ evaluation of food and drink (nutrient) requirements for normal body functions 177. Explain why the mitochondria are referred to as power plants. 178. Explain what is meant by oxidative phosphorylation. 179. Explain how the lack of oxygen would inhibit the Krebs cycle. 180. Show in an equation form the end products of glucose catabolism. Use one molecule of glucose and six molecules of oxygen to begin the equation. 181. The following mineral is important in bone formation, blood clotting and nerve function. A. phosphorus B. iron C. calcium D. cobalt 182. There are only two high energy phosphate bonds in adenosine diphosphate. A. True B. False 183. Polysaccharides, disaccharides and monosaccharides need digestion before they can be absorbed into the internal environment. A. True B. False 184. ATP is useful for the long-term storage of chemical energy derived from nutrients. A. True B. False 185. Both NAD and FAD can be used by the cell to transfer energy. A. True B. False 186. Oxygen is required for the last step of glycolysis. A. True B. False 187. An end product of the anaerobic pathway of glucose is lactic acid. A. True B. False 188. One function of lactic acid is to convert NADH back to NAD. A. True B. False 189. Glycogenesis is an example of carbohydrate anabolism. A. True B. False 190. Because red blood cells contain no mitochondria, they must get all of their energy through oxidative phosphorylation . A. True B. False 191. Fatty acids are broken down by a process of beta oxidation. A. True B. False 192. The body has an almost equal ability to store fats and carbohydrates. A. True B. False 193. Just as there are essential amino acids, there are essential fatty acids. A. True B. False Which of the following is not one of the openings that must be blocked when food moves from the pharynx into the esophagus? A. oropharynx B. nasopharynx C. larynx D. mouth 2. The process of swallowing is known as: A. mastication B. deglutition C. peristalsis D. segmentation 3. Which of the following is a true statement? A. the oral stage of swallowing is involuntary and under the control of the cerebral cortex B. the pharyngeal stage of deglutition is voluntary C. the esophageal stage of swallowing is involuntary D. both b and c 4. Which of the processes of mechanical digestion occur in the esophagus? A. deglutition B. peristalsis C. churning D. both a and b 5. The enterogastric reflex causes: A. secretion of digestive enzymes in the small intestine B. secretion of digestive enzymes in the stomach C. inhibition of gastric peristalsis D. acceleration of gastric peristalsis 6. Which of the following is not true of enzymes? A. They accelerate chemical reactions. B. They change chemically and are in the end products of the reaction. C. They are vital to chemical reactions. D. Many contain vitamins in their structure. 7. Which step of deglutition is under voluntary control? A. oral stage B. pharyngeal stage C. esophageal stage 8. The purpose of peristalsis is to: A. break apart chunks of food and mix it in digestive juices B. propel food forward along the GI tract C. absorb food D. enable swallowing 9. The hormone that inhibits gastric muscle, slowing passage of food into the duodenum, is called: A. gastric inhibitory peptide B. enterogastrone C. chyme D. cholecystokinin-pancreozymin 10. Structurally enzymes are: A. lipids B. carbohydrates C. proteins D. inorganic compounds 11. When classified according to the kind of chemical reactions catalyzed, digestive enzymes are: A. oxidation-reduction enzymes B. hydrolyzing enzymes C. phosphorylating enzymes D. hydrase enzymes 12. The group of enzymes that add water to a molecule without splitting it are called: A. hydrolases B. hydrases C. hydrogenases D. isomerases 13. Polysaccharides are hydrolyzed to disaccharides by enzymes known as: A. lipase B. proteases C. maltase D. amylase 14. Which of the following is not a property of enzymes? A. most enzymes catalyze a chemical reaction in only one direction B. enzymes function optimally at a specific pH C. many enzymes are synthesized as inactive proenzymes or zymogens D. enzyme action can be inhibited or inactivated by various physical and chemical agents that change the shape of enzyme molecules 15. The final product of carbohydrate digestion is a: A. disaccharide B. monosaccharide C. polysaccharide D. fatty acid 16. Which of the following is a disaccharide? A. glucose B. starch C. sucrose D. glycogen 17. The major final product that results from the digestion of carbohydrates is: A. glucose B. sucrose C. lactose D. maltose 18. The process of fat emulsification consists of: A. chemically breaking down fat molecules B. the secretion of digestive juices for fat digestion C. absorption of fats D. breaking fats into small droplets 19. Proteins are broken down into proteoses and peptides by proteases in: A. gastric juices B. pancreatic juices C. intestinal secretions D. both a and b 20. The enzyme pepsin begins the digestion of: A. carbohydrate B. protein C. fat 21. An end product of fat digestion is: A. glycerol B. glucose C. glycogen D. galactose 22. Cellulose is a residue of digestion that comes from: A. carbohydrates B. meat proteins C. undigested fats D. undigested connective tissue 23. The hormone that stimulates the release of bicarbonate substance from the pancreas is: A. enterogastrone B. secretin C. gastrin D. cholecystokinin-pancreozymin 24. The hormone that stimulates the gallbladder to release bile is: A. enterogastrone B. insulin C. gastrin D. cholecystokinin-pancreozymin 25. Which phase(s) of gastric secretion would be stimulated by the sight, taste, and smell of food? A. intestinal phase B. cephalic phase C. gastric phase D. all of the above 26. The major site for the absorption of the end products of digestion is the: A. stomach B. small intestine C. cecum D. large intestine 27. The sodium cotransport or coupled transport: A. transports sodium ions and glucose molecules passively out of the GI lumen B. transports sodium ions and glucose molecules passively into the GI lumen C. transports sodium ions and glucose molecules actively out of the GI lumen D. transports sodium ions and glucose molecules actively into the GI lumen 28. The intestinal hormone, cholecystokinin-pancreozymin: A. causes the pancreas to increase exocrine secretions high in enzyme content B. opposes the influence of gastrin on gastric parietal cells C. stimulates the contraction of the gallbladder D. all of the above 29. Bicarbonates are useful in the GI tract to: A. neutralize hydrochloric acid B. break down fats C. activate secretin D. activate pepsin 30. The hormone that stimulates the gallbladder to release bile is: A. enterogastrone B. secretin C. enterocrinin D. cholecystokinin-pancreozymin 31. The hormone thought to be a messenger causing release of digestive enzymes from the intestinal mucosa is: A. vasoactive intestinal peptide B. enterogastrone C. secretin D. cholecystokinin-pancreozymin 32. Chylomicrons are formed for the transport of: A. amino acids B. fats C. glucose D. vitamins 33. Glucose moves from the GI tract into the circulatory system by the process of: A. diffusion B. cotransport C. facilitated diffusion D. filtration 34. Which blood vessel carries absorbed food from the GI tract to the liver? A. hepatic artery B. hepatic vein C. portal vein D. renal artery 35. Bacterial toxins may damage the water-reabsorption mechanism of the intestinal mucosa, resulting in: A. constipation B. diarrhea C. cholera 36. The substances absorbed into the lymph capillaries are: A. glycerol and fatty acids B. glucose and glycerol C. amino acids and fatty acids D. glucose and amino acids 37. The blood vessel that carries absorbed food substances from the GI tract to the liver is the: A. renal artery B. hepatic artery C. hepatic vein D. hepatic portal vein 38. The bolus of food is formed during the pharyngeal stage of deglutition. A. True B. False 39. Respiration is inhibited for the one to three seconds required for food to clear the pharynx during each swallowing. A. True B. False 40. To propel food from the pharynx into the esophagus, three openings must be blocked. A. True B. False 41. Peristalsis is a back-and-forth action that breaks apart chunks of food and mixes in digestive juices. A. True B. False 42. The process of emptying the stomach takes about 12 hours after a meal. A. True B. False 43. After leaving the stomach, it normally takes about five hours for chyme to pass all the way through the small intestine. A. True B. False 44. Enzymes are unique in that they can function optimally within a wide range of pHs. A. True B. False 45. Enzymes are usually defined as "inorganic catalysts." A. True B. False 46. Pepsin is inactive in the presence of hydrochloric acid. A. True B. False 47. Amylases are found in saliva and in pancreatic juice. A. True B. False 48. Sucrose is an example of a disaccharide. A. True B. False 49. Most enzymes are able to work on more than one substance. A. True B. False 50. Large amounts of water work best to replace fluids quickly during exercise. A. True B. False 51. Amino acids are the end products of protein digestion. A. True B. False 52. Bile catalyzes the breakdown of fats. A. True B. False 53. The main glucose digesting enzyme is glucase. A. True B. False 54. Large amounts of cool, dilute, or isotonic fluids are best for replacing fluids quickly during exercise. A. True B. False 55. Peptides are broken down into proteoses by intestinal peptidases. A. True B. False 56. Cellulose, a carbohydrate, is broken down into maltose by enzymes in the pancreatic juices. A. True B. False 57. The stimulation of gastric juice secretion occurs in five phases controlled by reflex and chemical mechanisms. A. True B. False 58. Sucrase hydrolyzes sucrose into dextrose and levulose. A. True B. False 59. Secretin causes the production of pancreatic fluid high in enzyme content but low in bicarbonate. A. True B. False 60. The enterogastric reflex stimulates gastric motility as food enters the duodenum. A. True B. False 61. Salivary glands are stimulated only by olfactory and visual stimuli. A. True B. False 62. Bicarbonates are useful in the GI tract to neutralize hydrochloric acid. A. True B. False 63. Vasoactive intestinal peptide inhibits the production of intestinal juice. A. True B. False 64. The only food that can be digested by gastric juice is protein. A. True B. False 65. One of the functions of cholecystokinin-pancreozymin is to enhance the influence of gastrin on gastric parietal cells. A. True B. False 66. Vasoactive intestinal peptide inhibits the production of intestinal juice. A. True B. False 67. The sodium cotransport, which carries both sodium ions and glucose molecules, is an active transport mechanism. A. True B. False 68. Chylomicrons are composed mainly of neutral fats and some cholesterol covered by a delicate protein envelope. A. True B. False 69. Vitamins A, D, E, and K depend on bile salts for their absorption. A. True B. False 70. Both simple sugars and amino acids are absorbed into the blood in the intestinal capillaries. A. True B. False 71. Diarrhea occurs when the contents of the lower colon and rectum move at a rate that is slower than normal. A. True B. False 72. The formation of feces is the primary function of the rectum. A. True B. False 73. Micelles, formed from bile salts, carry fatty acids from emulsified droplets to the plasma membrane of absorptive cells. A. True B. False 74. The process of elimination is simply the expulsion of the residues of digestion from the digestive tract. A. True B. False 75. Diarrhea is one of the leading causes of infant mortality in developing countries. A. True B. False 76. Bacterial toxins may damage the water-reabsorption mechanisms of the intestinal mucosa resulting in diarrhea. A. True B. False 77. _____release of digestive juices; release of endocrine hormones that regulate digestion or metabolism of nutrients YOUR ANSWER: The suggested answer is D 78. _____excretion of the residues of the digestive process (feces) from the rectum, through the anus; defecation YOUR ANSWER: The suggested answer is C 79. _____movement by the muscular components of the digestive tube, including processes of mechanical digestion; examples include peristalsis and segmentation YOUR ANSWER: The suggested answer is A 80. _____movement of digested nutrients through the GI mucosa and into the internal environment YOUR ANSWER: The suggested answer is F 81. _____a group of processes that break complex nutrients into simpler ones, thus facilitating their absorption (includes both mechanical and chemical processes) YOUR ANSWER: The suggested answer is E 82. _____process of taking food into the mouth, starting it on its journey through the digestive tract YOUR ANSWER: The suggested answer is B 83. _____phase of gastric secretion that responds to taste, smell, thoughts of food, and sensations of chewing and swallowing YOUR ANSWER: The suggested answer is A 84. _____phase of gastric secretions that is controlled by the entrance of acidic chyme into the duodenum YOUR ANSWER: The suggested answer is C 85. _____phase of gastric secretion that is initiated by the presence of food in the stomach YOUR ANSWER: The suggested answer is B 86. _____ enzyme that works on starch YOUR ANSWER: The suggested answer is A 87. _____ converts maltose to glucose YOUR ANSWER: The suggested answer is D 88. _____ enzyme found in the mouth YOUR ANSWER: The suggested answer is A 89. _____ major enzyme in stomach associated with protein breakdown YOUR ANSWER: The suggested answer is E 90. _____ enzyme that works on milk sugars YOUR ANSWER: The suggested answer is C 91. _____ enzyme that works on cane sugars YOUR ANSWER: The suggested answer is G 92. _____ hydrochloric acid activates this enzyme YOUR ANSWER: The suggested answer is E 93. _____ pancreatic enzyme that works on proteins YOUR ANSWER: The suggested answer is H 94. _____enzyme from lining of small intestine that produces the end products of amino acids YOUR ANSWER: The suggested answer is F 95. _____ enzyme that works on malt sugars YOUR ANSWER: The suggested answer is D 96. _____ stimulates secretion of gastric juice rich in pepsin and hydrochloric acid YOUR ANSWER: The suggested answer is C 97. _____inhibits gastric secretion; stimulates secretion of pancreatic juice low in enzymes and high in alkalinity; stimulates ejection of bile by the gallbladder YOUR ANSWER: The suggested answer is A 98. _____stimulates ejection of bile from the gallbladder and secretion of pancreatic juice high in enzymes; opposes the action of gastrin, reducing the pH of gastric juice YOUR ANSWER: The suggested answer is B 99. _____ inhibits gastric secretion and motility YOUR ANSWER: The suggested answer is D 100. _____ inflammation of the liver YOUR ANSWER: The suggested answer is C 101. _____ failure of the small intestine to absorb nutrients properly YOUR ANSWER: The suggested answer is B 102. _____inflammation of abnormal saclike outpouchings of the intestinal wall called diverticula YOUR ANSWER: The suggested answer is D 103. _____an open sore or wound in an area of the digestive system that is acted on by acid gastric juice; generally occurs in the duodenum YOUR ANSWER: The suggested answer is F 104. _____ inflammation of the pancreas YOUR ANSWER: The suggested answer is E 105. _____an inflammatory condition of the large intestine, with symptoms of diarrhea and abdominal cramps or constipation YOUR ANSWER: The suggested answer is A 106. What are the three purposes of mechanical digestion? YOUR ANSWER: The suggested answer is 107. Explain the physiological basis for diarrhea and constipation. YOUR ANSWER: The suggested answer is 108. What happens in the chemical process of hydrolysis? YOUR ANSWER: The suggested answer is 109. What suffix is frequently used to denote an enzyme? YOUR ANSWER: The suggested answer is 110. Most enzymes catalyze a chemical reaction in both directions. Explain what is meant by this statement. YOUR ANSWER: The suggested answer is 111. List the six kinds of chemical substances that we eat. YOUR ANSWER: The suggested answer is 112. What three substances that we ingest have to be chemically digested? YOUR ANSWER: The suggested answer is 113. Describe the relationship between exercise and fluid uptake. YOUR ANSWER: The suggested answer is 114. What is a fecal fat test? How is it performed? When is it useful? YOUR ANSWER: The suggested answer is 115. Jeff was a successful country music star, but he worked too hard and was under great stress. His doctor cautioned him that if he did not alter his life style, he would be subject to hyperacidity. What could be the resulting condition of hyperacidity? YOUR ANSWER: The suggested answer is 116. Allen was an alcoholic. He had a condition known as alcoholic hepatitis. This condition causes inflammation of the liver and resulted in the reduction in the production and secretion of bile. What digestive complications did this produce? YOUR ANSWER: The suggested answer is 117. Donna has Crohn's disease, which results in inflammation and ulceration of the small intestine. Her physician recommended surgery to help in the management of this autoimmune disease. Could her entire small intestine be removed? Why or why not? YOUR ANSWER: The suggested answer is 118. The following structures all are involved in peristalsis except the A. esophagus B. small intestine C. pharynx D. stomach 119. The enzyme amylase functions best in A. an acid pH B. a base pH C. a neutral pH D. both A and B 120. "Contact digestion" occurs in this location in the digestive system A. mouth B. esophagus C. stomach D. small intestine 121. The disaccharide maltose is made up of these two saccharide units A. glucose and glucose B. glucose and fructose C. glucose and galactose D. none of the above 122. The disaccharide lactose is made up of these two saccharide units A. glucose and glucose B. glucose and fructose C. glucose and galactose D. none of the above 123. The disaccharide sucrose is made up of these two saccharide units A. glucose and glucose B. glucose and fructose C. glucose and galactose D. none of the above 124. The process of emulsification is important in the digestion of A. proteins B. fats C. polysaccharides D. disaccharides 125. Saliva contains all of the following substances except A. amylase B. lypase C. intrinsic factor D. mucus 126. Gastric juice contains all the following substances except A. intrinsic factor B. enterokinase C. hydrochloric acid D. pepsin 127. Pancreatic juice contains all the following substances except A. amylase B. trypsinogen C. enterokinase D. lypase 128. Bile contains all the following substances except A. bile salts B. lecithin C. amylase D. bilirubin 129. Pancreatic juice contains all the following substances except A. chymotrypsin B. nucleases C. amylase D. pepsinogen 130. The primary function of the digestive system is to bring essential nutrients into the internal environment so that they are available to the cells of the body. A. True B. False 131. Mastication is another word for chewing. A. True B. False 132. In deglutition, the mouth is closed off by the soft palate and the uvula. A. True B. False 133. In deglutition, the tongue closes off the nasopharynx. A. True B. False 134. In deglutition, food is denied entry to the larynx by muscle action that causes the epiglottis to block this opening A. True B. False 135. The involuntary part of swallowing is regulated by the deglutition center of the medulla. A. True B. False 136. Segmentation is described as a wavelike muscle contraction in a hollow organ which moves food through the digestive system. A. True B. False 137. The stomach releases gastric inhibitory peptide to slow down peristalsis in the duodenum. A. True B. False 138. Intestinal motility includes both peristaltic contractions and segmentation. A. True B. False 139. Most cells involved in the digestive system are intracellular enzymes. A. True B. False 140. Lipase can be called a hydrolase. A. True B. False 141. Most enzymes in the body are intracellular. A. True B. False 142. The specificity of enzyme function can be explained by their "key-in-a-lock" mode of action. A. True B. False 143. The reason that enzymes are pH sensitive is that differences in the hydrogen ion concentration can effect the shape of the protein molecule. A. True B. False 144. Because trypsin works in the small intestine, its optimal pH must be less than pepsin which works in the stomach. A. True B. False 145. Since enzymes are not changed by the chemical reactions they catalyze, digestive enzymes rarely need to be made. A. True B. False 146. Substances that activate proenzymes are often called kinases. A. True B. False 147. The process of emulsification actually is not an example of chemical digestion because no chemical change occurs in the substrate. A. True B. False 148. The hydrophilic portion of lecithin is attracted to the interior fat of the micelle. A. True B. False 149. The hydrophilic portion of lecithin is attracted to the exterior water of the micelle. A. True B. False 150. The process of emulsification is important because it adds a greater contact area for the digestion of fat A. True B. False 151. Lysophosphatide is a possible end product of fat digestion. A. True B. False 152. Colipase is a substance made by the small intestine and functions as a coenzyme in fat digestion. A. True B. False 153. When fat combines with magnesium it becomes undigestable. A. True B. False 154. One important role of the salivary glands is the production of mucus, because they are the only glands that produce it. A. True B. False 155. Since acid would be harmful to enzymes, the salivary glands produce bicarbonate ions to lower the pH of saliva. A. True B. False 156. Hydrochloric acid converts pepsinogen into pepsin. A. True B. False 157. Enterokinase converts trypsin into tyrpsinogen. A. True B. False 158. Enterokinase is converted to trypsinogen by trypsin. A. True B. False 159. Lecithin is secreted by the liver. A. True B. False 160. Bilirubin is found in bile and assists in micelle formation, which assists in the digestion of fats. A. True B. False 161. In the pancreas, base is secreted into the GI lumen and acid is secreted into the blood. This is the reverse of what happens in the stomach. A. True B. False 162. Elimination of gray-colored feces is an indication of abnormal bile secretion. A. True B. False 163. Gastric secretions are inhibited when chyme containing fats, carbohydrates and a high pH are present in the duodenum. A. True B. False 164. The hormones GIP, secretin, and CCK are secreted by the exocrine glands of the duodenum. A. True B. False 165. Micelles are formed in the GI lumen. A. True B. False 166. Chylomicrons are formed in the epithelial cells lining the small intestine. A. True B. False 167. Chylomicrons are absorbed by the blood vessels in the villi of the small intestine. A. True B. False 168. The nutrients absorbed by the lacteals enter the blood by being dumped into the subclavian veins. A. True B. False 169. About 20% of ingested alcohol is absorbed by the stomach. A. True B. False 170. The only voluntary activity of the GI tract is swallowing. A. True B. False 171. Some drugs can not be taken orally even if they are well absorbed by the small intestine because they are completely broken down by the liver. Explain why these drugs would never reach the general circulation. YOUR ANSWER: The suggested answer is Retake Test