SOLUTIONS TO THE STUDY GUIDE FOR MODULE #13 1. a. Mastication - The process of chewing b. Digestion - The breakdown of food molecules into their individual components c. Deglutition - The act of swallowing d. Peristalsis - The process of contraction and relaxation of circular smooth muscles which pushes food through the alimentary canal e. Gastric juice - The acidic secretion of the stomach f. Adventitia - A thin layer of loose connective tissue that binds an organ to surrounding tissues or organs g. Lumen - The hole in the center of a tube h. Macronutrients – The nutrients the body needs in large amounts: carbohydrates, fats, and proteins i. Micronutrients – The nutrients the body needs in small amounts, such as vitamins and minerals 2. a. tongue b. larynx c. trachea d. pancreas e. stomach f. small intestine g. anus h. parotid salivary gland i. sublingual salivary gland j. submandibular salivary gland k. pharynx l. esophagus m. lungs n. liver o. gall bladder p. transverse colon q. ascending colon r. descending colon s. cecum t. vermiform appendix u. rectum v. large intestine 3. a. The tongue is a part of the digestive system and is a part of the alimentary canal. It moves the food around in the mouth to form the bolus. It also provides a sense of taste. If you said it was not a part of the alimentary canal, that’s fine. It really depends on the way you look at things. b. The larynx is not a part of the digestive system. c. The trachea is not a part of the digestive system. d. The pancreas is a part of the digestive system but not a part of the alimentary canal. It makes several digestive enzymes as well as a base to neutralize the chyme. e. The stomach is a part of the digestive system and the alimentary canal. It churns and mixes the food with gastric juices. The gastric juices contain stomach acid which destroys bacteria that might have been eaten with the food, and it helps dissolve the food. The gastric juices also contain some digestive enzymes that start the chemical digestion of proteins. This turns the ingested food into chyme. f. The small intestine is a part of the digestive system and the alimentary canal. It chemically digests the food and allows the nutrients to be absorbed through its lining. g. The rectum is a part of the digestive system and the alimentary canal. It stores feces and then forces them out of the body through the anus. h. The salivary glands are a part of the digestive system. The are not a part of the alimentary canal. They put saliva in the mouth. The saliva partially digests starch, but it also lubricates the food and protects the mouth through its lysozyme and antibodies. i. The pharynx is a part of the digestive system and the alimentary canal. It pushes food into the esophagus. j. The esophagus is a part of the digestive system and the alimentary canal. It pushes food down into the stomach. k. The lungs are not a part of the digestive system. l. The liver is a part of the digestive system but not a part of the alimentary canal. It has many functions. The digestion-related function is to make bile. The other functions are nutrient interconversion, nutrient storage, synthesis, phagocytosis, and detoxification. m. The gall bladder is a part of the digestive system but not a part of the alimentary canal. It concentrates bile and squirts the bile into the chyme as the chyme enters the small intestine. Bile is a chemical that aids in the digestion of fats. n. The large intestine is a part of the digestive system and the alimentary canal. It consolidates undigested food, absorbs water from it, and turns the resulting waste into feces. Bacteria in the large intestine also produce beneficial vitamins. o. The appendix is a part of the digestive system. It is not a part of the alimentary canal. You might have thought that it was since it is attached to the large intestine, but it is not. It sort of “hangs” off the large intestine and food never passes through it. Its function is not completely understood. Many think that it is a disease-fighting organ. p. The anus is a part of the digestive system and the alimentary canal. It is the opening through which feces exit. 4. The epiglottis covers the larynx when you swallow. It stays open when you breathe. 5. Amylase can be found in saliva. It helps break polysaccharides down into smaller carbohydrates. 6. The soft palate rises and seals off the nasal cavity during deglutition. 7. From the outside to the inside you find the serosa or adventitia, the longitudinal muscularis, the circular muscularis, the submucosa, and the mucosa. The stomach has an extra layer: the oblique muscularis, which is deep to the circular muscularis. 8. The enzyme pepsin is secreted by the stomach. It breaks down proteins into peptides. Actually, pepsinogen is secreted by the stomach. It does not become pepsin until it hits the acid of the gastric juice. 9. The gastric glands produce mucus, which coats the stomach lining and protects it from its own gastric juice. 10. Intrinsic factor allows for the absorption of vitamin B12 by the small intestine. 11. The stomach can absorb water, alcohol, and aspirin. 12. Gastrin increases lower esophageal sphincter tone, decreases pyloric sphincter tone, increases the rate of secretion from the gastric pits, and increases the rate of mixing waves of the stomach. 13. In order from the stomach to the small intestine: duodenum, jejunum, and ileum. The duodenum is the smallest portion. 14. Circular folds and intestinal villi increase the surface area of the small intestine. Also, the cells which absorb the nutrients are covered with microvilli, which increase their surface area. 15. Secretin: Reduces gastric juice production and increases secretion of the acid-neutralizing juice from the pancreas, which increases the pH of the chyme. Cholecystokinin (CCK): Causes the gall bladder to contract. It also inhibits gastric secretion a bit, but not nearly as much as secretin does. It also increases the secretion of digestive enzymes from the pancreas Gastric inhibitory peptide (GIP): Decreases the rate at which the stomach empties. 16. Maltase: Breaks down maltose. Sucrase: Breaks down sucrose. Lactase: Breaks down lactose. Peptidase: Breaks down peptides. Enterokinase: Activates trypsinogen into trypsin. 17. A cell contains lots of proteins which are vital to its functions. Producing an active proteindigesting enzyme would kill the cell. 18. The bacteria produce vitamin K, biotin, and folic acid, which are absorbed in the large intestine. They also break down other chemicals that end up in the feces. 19. One way that chyme moves through the large intestine to the rectum is via mass movements. Mass movements are triggered by food entering the stomach. Thus, the act of filling the stomach triggers mass movements, which rapidly move chyme towards the rectum. 20. Blood travels from the portal triads to the central vein. Bile flows the opposite way. 21. Bile is not a digestive enzyme. It emulsifies fats, making them easier to digest. 22. The salivary glands and the pancreas produce amylase. 23. The four secretions which reduce the acidity of chyme are: alkaline mucus from the duodenal glands, intestinal juice from the intestinal glands, bile from the gall bladder, and bicarbonate in pancreatic juice. 24. Vitamins A, D, E, and K are fat-soluble. 25. Vitamins typically regulate the chemical processes in the body. 26. Vitamins D and K. Vitamin D is made from sunlight hitting the skin, and vitamin K is made by bacteria in the large intestine. It is still beneficial, however, to get these vitamins in your diet as well.