Download - 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


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


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


SECTION 24-1 The Digestive System


• The muscular digestive tract

• Various accessory organs

The Digestive system includes:

Copyright © 2004 Pearson Education, Inc., publishing as Benjamin Cummings Figure 24.1

Figure 24.1 The Components of the Digestive System


• Ingestion

• Mechanical processing

• Digestion

• Secretion

• Absorption

• Excretion

Functions of the digestive system


• 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


Figure 24.2 Mesenteries

Figure 24.2a



Figure 24.2b



Figure 24.2c



Figure 24.2d


• 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


• 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


Figure 24.3 The Structure of the Digestive Tract

Figure 24.3


• 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


Figure 24.4 Peristalsis

Figure 24.4


• 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


Figure 24.5 The Regulation of Digestive Activities

Figure 24.5