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Digestive systemOral cavity
1. Digestive system general feature 2. Oral cavity (lips, cheek, gingiva, soft and hard palate)
3. Tongue4. Salivary glands5. Tonsils6. Teeth 7. Periodontal membrane8. Development of teeth
Digestive system = digestive tube + glands
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Oral cavityFunctionsІ. Main 1. Digestion (ingestion,
mastication)2. Moistening of food
ІІ. Additional 1. Articulation2. Facial expression3. Sensory reception4. Respiratory
І. Mucosa1. Еpithelium – stratified squamous nonkeratinized epithelium (180-600 mkm)2. Lamina propria – loose connective tissue3. Muscularis mucosa-smooth muscular tissue
ІІ. Submucosa - loose connective tissue (glands)
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Lips
1. Hear-bearing skin : а) epithelium stratified squamous keratinized (4 layers)
• b) lamina propria (loose connective tissue with hair follicles sweat and sebaceous glands)
2. Transitional (vermilion): external (smooth) and internal zone
3. Mucosal а) epithelium stratified squamous nonkeratinized b) lamina propria (papillae)
• c) submucosa
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Lip
Minor salivarygland
Musculusorbicularis oris
Hair follicles
Skin surface
Sweat gland
Papillae of connective tissue
Blood vessel
Mucosa surface
Red borderof lip
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TongueFunctions1. Mechanical2. Receptory (general and taste)3. Articulation TunicesІ. MucosaІІ. SubmucosaІІІ. MuscularІV. Aponeurosis
Morphofunctional peculiarities of the lover surface of the tongue1. Thin permeable epithelium 2. Well prominent blood supply 3. Salivary glands
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CheeksCheek surfaces1. External (skin)2. Internal (mucosa)• І. Skin • ІІ. Muscle• ІІІ. MucosaMucosa zones1. Upper (maxillary)2. Lover (mandibulary)3. Intermediate (no salivary glands, parotid glands ducts)1. Mucosa• а) stratified squamous nonkeratinized epithelium (smear);• б) lamina propria (dense connective tissue, elastic fibers).2. Submucosa (salivary glands).3. Muscular tunic (skeletal muscle). Adipose body of Bisha.
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Palate
• Separates oral and nasal cavity• І. Hard palate• Zones 1. Adipose• 2. Mucous• 3. Marginal• 4. Middle line (epithelial bodies)• ІІ. Soft palate • Oral surface (strutified squamous nonkeratinized
epithelium)• Nasal surface (ciliated epithelium)
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Tonsils• Lymph epithelial ring of Pirogov-Waldeier
7 tonsils : 2 tubular, 2 palatine, lingual, pharyngeal, laryngeal
Functions 1. Protective2. Immune
І. Mucosa:а) epithelium stratified squamous nonkeratinized infiltratedb) lamina propria – loose connective tissue with B lymphocytes)
ІІ. Submucosa – septae, capsuleІІІ. Muscular tunic skeletal muscle
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Tonsil
Stratified squamousnonkeratinized
epithelium
Skeletal muscle
Crypt
Connective tissue septae
Lymph nodules
Crypt
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Salivary glands major (3pairs) + minor
Functions 1. Exocine (saliva secretion)
2. Desinfection 3. Digestion4. Articulation
2. Endocrine (parotin, VIP, glukagon, kallikrein, renin ...)3. Excretion4.Homeostatic
Saliva Water -99%Minerals (Na, K, Cа, Fe, I…)Organic matters (enzymes, mucous)Cells (leucocytes, epithelial)
MFU – Acinus = secretory portion+ intercalated duct+ striated duct
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Intercalatedducts
Myoepithelialcells
Intercellularcanaliculi
Myoepithelial cells
Serousdemilunar
Mixed acinus
Striated duct
Intercalated duct
Serousacinus
Serocytes
Mucous acinusMucocytes
Basementmembrane
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Teeth 1. Functions 2. Structure 3. Deciduous and permanent teeth4. Enamel 5. Dentin 6. Cementum 7. Pulp 8. Periodontal membrane9. Development of teeth
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• Functions
1. Mastication
2. Articulation
3. Esthetic
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Lip, tooth, gingiva
• red boarder
skeletal muscle
minor salivary glands
skin with hair
cementum
tooth apex
channel of tooth
enamel
gingival fissure
periodontum
pulp
dentin
muscle
gingiva
alveolar bone
lip furrow
mandible
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Deciduous teeth (20) 1. Smaller 2. Crown lower and wider3. Shorter roots
Incisors central and lateralCuspids (canines)Molars Eruption – 6 months- 2 years 12 years
Permanent teeth (32)IncisorsCuspids Bicuspids (premolar)sMolars
Eruption -
2012/21022012/2102
3212/21233212/2123
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Enamel
1. Covers crown
2. 2,5 mm
3. Hardest tissue
Chemical composition
1) 96-97 % – mineral salts (Са hydroxyapatites, fluorides, carbohydrates)
2) 3-4 % – organic substance (fibrillar matrix)
MFU – hexagonal enamel rod (S-shaped enamel prism)
Retzius, 1835
5-12 mln in tooth
4-8 мm
Enamel rods
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Rods are formed by ameloblasts
Fur – microorganisms and + mineral and organic substances
Pellicle - glycoproteins
(II keratinous membrane)
Cuticle – ameloblats remnants (I Nasmyth’s membrane)
Enamelorgan
reticulum
Apicalterminal bar
Basalterminal bar
RER
Tome’s process
Golgi complex
Nucleus
Mitochondria
Enamel
Secretorygranules
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Enamel lamellae –thin leaflike structures
(septae)
Enamel bundles - near dentino-enamel junction
Enamel tuft (spindle)
Retzius incremental lines
Hunter-Schreger bands
Dentin
Enamel
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Dentin
Chemical composition
1) 72 % – mineral salts (Са and Mg phosphates, carbohydrates, fluorides)
2) 28 % – organic substance (collagen fibers)
Calcified dentin - dentinal tubules with Tomes’ fibers
Mantle dentin (radial Korff’s fibers)
Inner dentin (tangential Ebner fibers – imbrication lines)
Contour lines of Owen
Uncalcified dentin – predentin (odontoblasts in pulp)
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Peritubular dentin – Neumans’ sheath (less fibers)
Intertubular dentin – contains calcium crystals and globules
(linear and globular calcification)
Interglobular dentin – hypocalcified ground substance
Tomes’ granular layer- a thin layer of dentin adjacent to cementum (in the root)
Peritubulardentin
Dentin tubules
Odontoblastprocess
Dentin cross section
Intertubulardentin
Dentintubul
Peritubulardentin
Intertubulardentin
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Dentin
Odontoblastsprocess
Odontoblastnucleus
Predentin
Odontoblasts
Pulp
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Odontoblast
1. Lies in the pulp
2. Produces dentin
3. Promotes regeneration
Dentin tubule
Dentin
Predentin
RER
Calcificationzone
Odontoblastprocecss
Terminal bar
RER
GA
Mitochondria
Odontoblastnucleus
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Primary dentin - regular
Secondary dentin – forming pulpward of the
demarcation line (on the pulpal surface)
Transparent dentin – sclerotic (Ca salts are deposed in tubule and oblitarate it )
Dead tract (black)- empty tubules are filled with air
Denticles – pulp stones
1. True (tubuli and cells) 1. Free (in pulp)
2. False (concentric calcified) 2. Adherent (attached)
3. Diffuse calcifications 3. Embedded (in dentin)
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Cementum 1835 two Purkinje pupils
1. Cellular (cementocytes)
2. Acellular
Chemical composition
1. 65 % – inorganic substances
(Са(РО3)2, СаСО3)
2. 23 % – organic material
(collagen fibers and ground substance)
3. 12 % – water
Cemento-enameljunction
Apical foramen
Root
Odontoblasts
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Pulp – soft tissue
Functions1. Formative2. Nutritive3. Sensory 4. Protective
In the crownIn the root
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Pulp layers
1. Peripheral – odontoblasts and immature collagen fibers
2. Intermediate – preodontoblasts and precollagen fibers– Acellular zone of Weil
(cell-free layer in the crown of old teeth)
3. Central – loose connective tissue with blood vessels and nerves
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Periodontal membrane
(ligament)
1. Formative
2. Supportive
3. Sensory
4. Nutritive
Epithelial rests of
Malassez (Hertwig’s
epithelial root sheath)
Cementicles
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Parodontum = gingiva + alveola + periodontum
Circular ligament (10 )
Periodontum: 1) marginal (4)
2) proper (2)
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Developmentalstages
1. Dental laminaand bud
2. Enamel organ(cap and bell stage)
3. Histogenesis, organogenesis
TongueDeciduous tooth bud
DPMesenchyme
MaxillaMaxilla
Dentalpapilla
Enamel organDental
Lamina DL
Low lip
Dental papilla
A
DC
B
Enamelorgan P
Dentalpapilla P
Maxilla
Dental sac
Low lip
Enamel organ
Dentin
Enamel
Pulp
DL remnant
Dentin
ReducedEO
EnamelPermanent
tooth
Dental lamina
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Tooth eruption and replacement
1870 Hunter – root growth
1929,1936 Jasvoin – dental pupilla
1940 Kutz – bony tissue +pressure in pupilla
Dental sac
Enamelorgan
EnamelDentinPulp
Dental sac
Osteoclasts
DentinPulp
Periodontum
EnamelPermanent tooth
Pulp
Enamel
Dentin Periodontum
EnamelDentin
Pulp
Deciduous tooth Zone of eruption
Permanent tooth
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Teeth eruptionDeciduous
(months)
No Teeth Permanent (years)
First molar 5-6
6-8 1 Incisor central 7-8
8-12 2 Incisor lateral 8-9
3 First premolar 9-10
16-20 4 Canine/cuspid 10-13
5 Second premolar 11-12
14-16 6 First molar 5-6
7 Second molar 12-13
20-24 8 Third molar 18-25