Chapter 24, part 1
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Transcript of Chapter 24, part 1
Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings
Fundamentals of
Anatomy & PhysiologySIXTH 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
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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
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
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SECTION 24-1 The Digestive System
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• The muscular digestive tract
• Various accessory organs
The Digestive system includes:
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Figure 24.1 The Components of the Digestive System
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• Ingestion
• Mechanical processing
• Digestion
• Secretion
• Absorption
• Excretion
Functions of the digestive system
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• 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
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Figure 24.2 Mesenteries
Figure 24.2a
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Figure 24.2 Mesenteries
Figure 24.2b
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Figure 24.2 Mesenteries
Figure 24.2c
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Figure 24.2 Mesenteries
Figure 24.2d
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• 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
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• 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
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Figure 24.3 The Structure of the Digestive Tract
Figure 24.3
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• 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
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Figure 24.4 Peristalsis
Figure 24.4
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• 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
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Figure 24.5 The Regulation of Digestive Activities
Figure 24.5