1. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Fundamentals of Anatomy & Physiology SIXTH EDITION Frederic H. Martini PowerPoint ® Lecture Slide Presentation prepared by Dr. Kathleen A. Ireland, Biology Instructor, Seabury Hall, Maui, Hawaii Chapter 24, part 1 The Digestive System

2. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Learning Objectives Identify the organs of the digestive system and their major functions Outline the mechanisms that regulate digestion Describe the anatomy of the organs and accessory organs of the digestive system Discuss the functions of the major structures and regions of the digestive system and discuss the regulation of their activities

3. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Learning Objectives Explain the significance of the large intestine in the absorption of nutrients Describe the events involved in the digestion of organic and inorganic nutrients Summarize the effects of the aging process on the digestive system

4. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings SECTION 24-1 The Digestive System

5. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings The muscular digestive tract Various accessory organs The Digestive system includes:

6. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24.1 Figure 24.1 The Components of the Digestive System

7. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Ingestion Mechanical processing Digestion Secretion Absorption Excretion Functions of the digestive system

8. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Mesenteries Sheets of serous membranes that support portions of the digestive tract Greater omentum lies anterior to abdominal viscera Provides padding, protection, insulation, and energy reserves Lesser omentum The digestive system organs and the peritoneum

9. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24.2 Mesenteries Figure 24.2a

10. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24.2 Mesenteries Figure 24.2b

11. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24.2 Mesenteries Figure 24.2c

12. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24.2 Mesenteries Figure 24.2d

13. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Mucosa lines digestive tract (mucous epithelium) Moistened by glandular secretions Lamina propria and epithelium form mucosa Submucosa Layer of dense irregular connective tissue Histological organization of the digestive tract

14. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Muscularis externa Smooth muscle arranged in circular and longitudinal layers adventitia Serosa Serous membrane covering most of the muscularis externa Histological organization of the digestive tract

15. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24.3 The Structure of the Digestive Tract Figure 24.3

16. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Visceral smooth muscle shows rhythmic cycles of activity Pacemaker cells Peristalsis Waves that move a bolus Segmentation Churn and fragment a bolus Movement of digestive materials

17. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24.4 Peristalsis Figure 24.4

18. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Movement of materials along the digestive tract is controlled by: Neural mechanisms Parasympathetic and local reflexes Hormonal mechanisms Enhance or inhibit smooth muscle contraction Local mechanisms Coordinate response to changes in pH or chemical stimuli Control of the digestive system

19. Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24.5 The Regulation of Digestive Activities Figure 24.5