1.

2. METABOLISM
3. Anatomy and Physiology
4. MOUTH
5. The mouth, buccal cavity, or oral cavity is the first portion of the alimentary canal that receives food and begins digestion by mechanically breaking up the solid food particles into smaller pieces and mixing them with saliva.
Lined with epithelial cells and mucuous membrane
Lip muscle: orbicularisoris
6. TEETH
7. Enamel is the hardest and most highly mineralized substance of the body, the outer layer of tooth
Dentin is the substance between enamel or cementum and the pulp chamber that acts as a protective layer and supports the crown of the tooth
Cementum is a specialized bony substance covering the root of a tooth. Its principal role of cementum is to serve as a medium by which the periodontal ligaments can attach to the tooth for stability
The dental pulp is the central part of the tooth filled with soft connective tissue. This tissue contains blood vessels and nerves that enter the tooth from a hole at the apex of the root
8. 9. Digestion is the mechanical and chemical breaking down of food into smaller components, to a form that can be absorbed
10. Chewing
Or mastication, is the mechanical process of breaking down food into smaller particles
11. Saliva
Is secreted by the sublingual and submandibular and parotid glands
Function: is to lubricate and soften food mass
Contains the enzyme ptyalin (amylase) which breaks down starches to maltose
Chewed food is then called bolus
12. Swallowing
Or deglutition, is the act of passing down food/ bolus from the mouth down to the esophagus
13. Esophagus
A hollow, muscular tube the lies posterior to the trachea and larynx
Serves as the passage of food from the mouth to the stomach
The Lower esophageal sphincter , a zone of increased pressurethat provides a physiologic barrier to protect the esophageal mucosafrom the effects of gastric reflux
14. Peristalsis
Are involuntary wavesof the glosopharyngeal nerves stimulated by the act of swallowing
Secondary stimulation of peristalsis occurs with dilatation of the lower half of the esophaus
15. The Stomach
Has 3 anatomic divisions:
The fundus, lies aboveand to the left of the cardiac sphincter
The body
The antrum or pylorus
16. Sphincters
Regulate inflow and outflow from the stomach.
The cardiac sphincter at the proximal end of the stomach allows inflow of food and preventsbackflow of material
The pyloric sphincter lies between the distal end of the stomach and the duodenum permits the flow of chyme from the stomach
17. Stomach
Has four layers
Serous- the visceral peritoneum
Muscular- produces peristaltic movements
Submucous- contains blood, lymph and nerve plexuses
Mucous-epithelial cells with microscopic glands
18. Chief cells- secrete mucus and pepsinogen
Parietal cells- secrete hydrochloric acid, stimulated by gastrin. Also secrete the intrinsic factor
Neck cells- secrete mucus
Pyloric glands- secrete gastrin
19. Stomach
Functions:
Storage
Mixing and liquefication of bolus into chyme
Blood supply: celiac artery
Drainage: portal vein
20. Innervation:

Vagus nerve- parasympathetic stimulation

21. Results in increased secretion of gastrin and pepsin and increased gastric motor activity 22. The greater splanchic nerve and celiac ganglia- sympathetic innervation 23. Inhibits gastric secretion and motility