1. PowerPoint Presentation to accompany Hole’s Human Anatomy and Physiology, 9/e by Shier, Butler, and Lewis

2. UNIT FIVE

3. Chapter 17
Digestive System

4. Alimentary Canal Mucosa
surface epithelium with underlying connective tissue and small amount of smooth muscle
contains glands, including mucus glands
carries on secretion and absorption

5. Alimentary Canal Figure 17.1 Submucosa
loose connective tissue with glands, blood and lymphatic vessels, and nerves
Figure 17.1

6. Alimentary Canal Muscular layer Serosa or serous layer
two layers of smooth muscle
circular fibers compose inner coat
longitudinal fibers compose outer coat
Serosa or serous layer
visceral peritoneum
epithelium on the outside and connective tissue beneath, secretes serous fluid

7. Figure 17.3

8. Movement of the Tube Figure 17.4 Mixing movements Propelling movements
smooth muscles contract rhythmically
mix food with digestive juices
Propelling movements
wavelike movements called peristalsis
receptive relaxation occurs ahead of peristalsis
Figure 17.4

9. Innervation of the Tube
Parasympathetic impulses increase digestive system activities
Sympathetic impulses decrease digestive system activities
Submucosal plexus
controls secretion by the GI tract
Myenteric plexus
muscular layer, controls motility

10. Mouth Figure 17.5 Cheeks Lips Tongue muscles of expression and chewing
contain skeletal muscles and sensory receptors
Tongue
tongue muscles mix food
taste buds provide sensation
lingual tonsils are lymphatic tissue at the root of the tongue
Figure 17.5

11. Figure 17.6

12. Palate Figure 17.7 Roof of the oral cavity hard palate is anterior
soft palate is posterior and ends in the uvula
Figure 17.7

13. Palate Figure 17.7 Palatine tonsils Pharyngeal tonsils (adenoids)
located in the back of the throat
Pharyngeal tonsils (adenoids)
located above the soft palate
Figure 17.7

14. Teeth Figure 17.9 Primary or deciduous teeth
20 teeth, erupt between 6 months and 4 years
Secondary or permanent teeth
32 teeth, erupt between 6 and 25 years of age
incisors, cuspids, bicuspids, molars
Teeth break food into small pieces
Figure 17.9

15. Teeth
Crown
projects out from the gum
covered with enamel
Figure 17.10

16. Teeth Root Dentin anchored to the jaw by the periodontal ligament
covered with cementum
Dentin
living tissue similar to bone, but harder
surrounds the pulp cavity which contains nerves and blood vessels

17. Saliva Saliva moistens food
Saliva contains bicarbonate ions that buffer acids in the mouth
Two types of secretory cells
serous cells
secrete a watery fluid contains amylase, an enzyme that splits starch and glycogen into disaccharides
mucous cells
secrete a thick fluid, mucus, that binds and lubricates

18. Salivary Glands parotid glands submandibular glands sublingual glands
largest, secrete watery fluid rich in amylase
submandibular glands
secrete a viscous fluid
sublingual glands
smallest, secrete thick mucus fluid
Innervation
sympathetic impulses stimulate a small amount of viscous secretion
parasympathetic impulses stimulate a large volume of watery saliva

19. Figure 17.11

20. Pharynx Nasopharynx Oropharynx Laryngopharynx
communicates with the nasal cavity, air passage
Oropharynx
posterior to the mouth, passage for food and air
Laryngopharynx
inferior to the oropharynx, leads to esophagus