DIGESTIVE SYSTEM

2. DIGESTIVE SYSTEM

3. ORAL CAVITY • Oral cavity consists of the mouth and its structures, which include the tongue, teeth and their supporting structures (periodontium), major and minor salivary glands, and tonsils. • Divided into vestibule and oral cavity proper.

5. MUCOSA • A mucous tissue lining various tubular structures consisting of epithelium, lamina propria, and, in the digestive tract, a layer of smooth muscle (muscularismucosae).

6. MUCOSA OF ORAL CAVITY Masticatory mucosa • Has a keratinized and parakeratinized stratified squamous epithelium • Found in gums and hard palate

7. Lining mucosa Non keratinized epithelium Few papillae Found on lips, cheeks,floor of oral cavity

8. Specialized mucosa Associated with taste sensation Restricted to dorsal surface of tongue

10. LIPS • Cutaneous area • Red area • Oral mucosa

15. CHEEKS • Skin with sebaceous and sweat glands • Mucosa lined by Stratified squamous non cornified epithelium • Lamina propria is compact, contain papilla and connected by a submucosa to the underlying skeletal muscle. • Submucosa has elastic fibers and tubuloalveolar glands

17. GUMS • Epithelium • Lamina propria • No submucosa and no glands

18. HARD PALATE • Epithelium keratinized • Long vascular papillae • Periosteum of the hard palate • Submucosa with collagen fibers and gland

19. SOFT PALATE • Oral surface • Pharyngeal surface • Mucosa • Submucosa • Glands • Skeletal muscles

20. TONGUE • The main bulk of the tongue, particularly of the anterior two-thirds, is skeletal muscle.

21. The interlacing muscle fibers course chiefly in three directions, longitudinally, transversely, and vertically, an arrangement which gives maximal mobility and physical control.

23. LOWER SURFACE • Stratified squamousnoncornified epithelium • Lamina propria is thin and closely bound to underlying muscle.

24. DORSAL SURFACE • Anterior 2/3: Lingual papillae • Posterior 1/3: Mucosal ridges and lingual tonsils • No submucosa

26. FILIFORM PAPILLAE • Most numerous • Smallest • Evenly distributed • Slender core of vascular epithelium • Stratified squamous epithelium • Secondary projections

27. FUNGIFORM PAPILLAE • Few in number • Interspersed among the filiform papillae • Rounded summits and broader bases • Noncornified epithelium • Highly vascular connective tissue

28. 1.STRATIFIED SQUAMOUS NONCORNIFIED EPITHELIUM 2.LAMINA PROPRIA 3.TASTE BUD

29. FOLIATE PAPILLAE • Along the posterolateral border of the tongue there are folds of the mucous membrane, sometimes called the foliate papillae. • Not well developed in humans. • In some animals,e.g.,rabbits, it constitute the principle site of aggregation of taste buds.

30. CIRCUMVALLATE PAPILLAE • 9-12 in number • Resemble fungiform papillae • Much larger • Surrounded by a trench and a wall • Small oval bodies, taste buds

32. TASTE BUDS

34. TASTE SENSES

35. DORSAL SURFACE OF THE POSTERIOR THIRD OF THE TONGUE • Free of papillae • Has mucosal ridges and lingual tonsils

36. TEETH

37. ANATOMICAL DIVISION • Crown • Root • Neck

38. COMPONENTS OF TOOTH • Enamel • Dentin • Cementum • Pulp

39. ENAMEL • Consists of Enamel rods Inter rod enamel • Secreted by ameloblasts • At apical pole------Tomes process • At the base---------cluster of mitochondria

40. ENAMEL • Acellular mineralized tissue that covers the crown of tooth • Hardest substance in the body • Once formed, can't be replaced • 96-98% exist mainly as hydroxyapatite crystals

41. DENTIN • Calcified tissue harder than bone • Dentin is produced by neural crest derived odontoblasts of the adjacent mesenchyme • Sensitive structure

43. Cementum Alveolar bone proper Periodontal ligament Gingiva PERIODONTIUM

45. PULP • A C.T. compartment bounded by the tooth dentin • Apical foramen • Vascular & neural networks • Cavity decreases with age

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