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Essentials of Anatomy and Physiology

Fifth edition

Seeley, Stephens and Tate

Slide 2.1Copyright 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Chapter 16: digestive System

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The Digestive System

Slide 14.1Copyright 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Second system to function in embryo

A tube within a tube

Material is not inside body

Humans are omnivores

Diet tempered by culture, situation

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The Digestive System

Slide 14.1Copyright 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Functions:

Ingestion: taking food in

Digestion: changes big food into littlefood

Mechanical

Chemical

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The Digestive System and Body

Metabolism

Slide 14.1Copyright 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Absorption

Molecules enter body

Via transport into blood

Egestion: eliminating wastes

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Organs of the Digestive System

Slide 14.2bCopyright 2003 Pearson Education, Inc. publishing as Benjamin CummingsFigure 14.1

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Organs of the Digestive System

Slide 14.2aCopyright 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Two components

Alimentary canal continuous coiledhollow tube

Accessory digestive organs everythingelse

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Organs of the Alimentary Canal

Slide 14.3Copyright 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Mouth

Pharynx

Esophagus Stomach

Small intestine

Large intestine

Anus

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Organs of the Digestive System

Slide 14.2bCopyright 2003 Pearson Education, Inc. publishing as Benjamin CummingsFigure 14.1

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Mouth (Oral Cavity) Anatomy

Slide 14.4Copyright 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Lips (labia)

Cheeks

Hard palate Soft palate

Uvula

Figure 14.2a

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Mouth (Oral Cavity) Anatomy

Slide 14.5Copyright 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Vestibule

Oralcavity: space

Tongue:

attached to bone

lingual frenulum

Figure 14.2a

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Mouth (Oral Cavity) Anatomy

Slide 14.6Copyright 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Tonsils

Palatine tonsils

Lingual tonsil

Figure 14.2a

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Digestive Functions of the Mouth

Slide 14.7Copyright 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Mastication (chewing) of food

Mixing food with saliva

Initiation of swallowing

by the tongue

Taste receptors

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Digestive Functions of the Mouth

Slide 14.48Copyright 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Mechanical digestion

Food broken down by chewing

Chemical digestion

Food mixed with saliva

Starch digestion begins

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Pharynx Anatomy

Slide 14.8Copyright 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Nasopharynx

Oropharynx:posterior to oral

cavity Laryngopharynx:

posterior to larynx

Connects toesophagus

Figure 14.2a

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Pharynx Function

Slide 14.9Copyright 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Passageway for air and food

Moves food to esophagus by musclecontraction

Longitudinal inner layer

Circular outer layer

Peristalsis: wave-like contractions

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Esophagus

Slide 14.10Copyright 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Extends from pharynx to stomach

passes through the diaphragm

Conducts food by peristalsis

Passageway for food only

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Activities of the Pharynx and

Esophagus

Slide 14.49Copyright 2003 Pearson Education, Inc. publishing as Benjamin Cummings

These organs have no digestive function Serve as passageways to the stomach

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Deglutition (Swallowing)

Slide 14.52Copyright 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Figure 14.13

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Layers of Organs in Alimentary

Canal

Slide 14.11aCopyright 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Mucosa

Innermost layer

Simple columnar E.T.

Lots of Goblet cells

Protects, secretes, absorbs

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Layers of Alimentary Canal Organs

Slide 14.13Copyright 2003 Pearson Education, Inc. publishing as Benjamin CummingsFigure 14.3

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Layers of Alimentary Canal Organs

Slide 14.11bCopyright 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Submucosa

Deep to mucosa

Loose connective tissue

blood vessels

nerve endings

lymphatics

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Layers of Alimentary Canal Organs

Slide 14.13Copyright 2003 Pearson Education, Inc. publishing as Benjamin CummingsFigure 14.3

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Layers of Alimentary Canal Organs

Slide 14.12Copyright 2003 Pearson Education, Inc. publishing as Benjamin Cummings

Muscularis: smooth muscle

Inner circular layer

Outer longitudinal layer

Serosa

Outermost layer = visceral peritoneum

Serous membrane

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Layers of Alimentary Canal Organs

Slide 14.13Copyright 2003 Pearson Education, Inc. publishing as Benjamin CummingsFigure 14.3