Lab 18 The Digestive System Laboratory Objectives Identify on a diagram, model or cadaver the parts of the digestive system and accessory organs. Describe the general histology of the digestive system. Analyze the pathophysiology of gastric pain (upper GI tract disease). Recognize the steps of mechanical and chemical digestion. Compare mechanical and chemical digestion. Analyze the pathophysiology of occult blood in the stool (lower GI tract disease). Describe the source and action of enzymes in the GI tract. Characterize the absorption of digested nutrients. List and describe the movements providing GI tract motility. 1
Activity 1: Cadaver Video: The Digestive System Navigation: WileyPlus > Read, Study, and Practice > Chapter 24. The Digestive System > See > Cadaver Video: The Digestive System (13:00) 1. Can you name the organs of the GI tract in order? 2. Can you name the accessory organs of digestion? 3. Can you name the structures of the oral cavity? (Note that much of this material is a review of what we learned in the previous Module.) 4. What is the difference between deciduous teeth and permanent teeth. 5. What are the four regions of the stomach? 6. What are the three regions of the small intestine? 7. What is the name of the structure where the pancreas secretes its products into the intestine? Which region of the small intestine does this happen in? 8. What are the divisions of the large intestine? 9. What are the two sphincters of the anus? Why are these important for your acceptance into a polite society? 10. Which blood vessels supply the liver, and what are their functions? Why does the liver receive both oxygenated and deoxygenated blood? 11. What is the relationship between liver and gall bladder? 2
Activity 2: PowerAnatomy > PowerAnatomy > Table of Contents > The Digestive System Review the following topics (left column): The Peritoneum Gastrointestinal Tract Organs Accessory Digestive Organs Complete Exercises (bottom-right link): A. Gastrointestinal Tract Organs B. Digestive Organ Structures C. Accessory Digestive Organs and the Peritoneum 3
Activity 3: Visual Anatomy > Visual Anatomy > Digestive System > Cadaver Practicals Review: Intestines, Anterior view Sections of the large intestine Mandible, permanent teeth, Right lateral view Stomach, Anterior view of internal anatomy Pancreas, liver, gallbladder, duodenum, Anterior view 4
Activity 4: Digestive System Histology > Anatomy Overview: Digestive System Histology 1. Name the four general layers of the GI tract from deep to superficial. 2. What does the pancreas secrete to contribute to digestion? 3. Why is the epithelium of the esophagus stratified squamous, but the intestinal mucosa is simple columnar? 4. How does the muscle in the stomach compare to the other digestive organs? 5
Activity 5: The Case of the Burning Abdomen Navigation: WileyPlus > Read, Study and Practice > Chapter 24. The Digestive System > Do > Homeostatic Imbalances: The Case of the Burning Abdomen 1. What is meant by epigastric pain? 2. Why would he have black, tarry stools? 3. What is the difference between an endoscopy and a colonoscopy? 6
Activity 6: Mechanical and Chemical Digestion Navigation: WileyPlus > Read, Study and Practice > Chapter 24. The Digestive System > See > Animation: Mechanical Digestion in the Gastrointestinal Tract Navigation: WileyPlus > Read, Study and Practice > Chapter 24. The Digestive System > See > Animation: Chemical Digestion in the Gastrointestinal Tract 1. What is the difference between mechanical and chemical digestion? If someone explained a process of digestion, how would you tell if it were mechanical or chemical in nature? 2. What is the cell type in the gut wall that allows for mechanical digestion? 3. What part of the digestive system is under voluntary control (hint: don t forget both ends of the digestive system)? How is the remainder of the digestive system controlled? 4. Where does bicarbonate in the digestive system come from? Where is it released? What is its purpose? 7
Activity 7: Match the Movement > Interactive Exercise: Match the Movement 1. Which processes in digestion are voluntary and which are involuntary? 2. How does the histology and physiology of the GI tract contribute churning and peristalsis? 3. What are haustra? 8
Activity 8: Digestive Enzymes > Interactive Exercise: Digestive Enzyme Activity 1. Which two structures produce amylase? 2. At what ph is pepsin active? Trypsin? 3. Where are the enzymes maltase, sucrase, and lactase located? 9
Activity 9: Nutrient Absorption > Interactive Exercise: Nutrient Absorption Routes 1. Why do large fatty acid molecules diffuse out of the intestinal lumen, but smaller glucose molecules are moved by secondary active transport. 2. What is the difference between primary active transport and secondary active transport? 3. Why do fatty acids and glycerides enter the lacteals and not the capillaries? 10
Activity 10: The Case of the Woman with Bloody Stools > Homeostatic Imbalances: The Case of the Woman with Bloody Stools 1. Whar are polyps? Are they fast or slow growing? 2. What medical procedure detects abnormal tissues in the colon? 3. Why is the patient jaundice? 11