Digestive system Oral cavity 1. Digestive system general feature 2. Oral cavity (lips, cheek, gingiva, soft and hard palate) 3. Tongue 4. Salivary glands 5. Tonsils 6. Teeth 7. Periodontal membrane 8. Development of teeth Digestive system = digestive tube + glands

Oral cavity Functions І. Main 1. Digestion (ingestion, mastication) 2. Moistening of food ІІ. Additional 1. Articulation 2. Facial expression 3. Sensory reception 4. Respiratory І. Mucosa 1. Еpithelium – stratified squamous nonkeratinized epithelium ( mkm) 2. Lamina propria – loose connective tissue 3. Muscularis mucosa-smooth muscular tissue ІІ. Submucosa - loose connective tissue (glands)

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

Lip Minor salivary gland Musculus orbicularis oris Hair follicles Skin surface Sweat gland Papillae of connective tissue Blood vessel Mucosa surface Red border of lip

Tongue Functions 1. Mechanical 2. Receptory (general and taste) 3. Articulation Tunices І. Mucosa ІІ. Submucosa ІІІ. Muscular ІV. Aponeurosis Morphofunctional peculiarities of the lover surface of the tongue 1.Thin permeable epithelium 2.Well prominent blood supply 3.Salivary glands

Cheeks Cheek surfaces 1. External (skin) 2. Internal (mucosa) І. Skin ІІ. Muscle ІІІ. Mucosa Mucosa zones 1. 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.

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)

Tonsils Lymph epithelial ring of Pirogov-Waldeier 7 tonsils : 2 tubular, 2 palatine, lingual, pharyngeal, laryngeal Functions 1. Protective 2. Immune І. Mucosa: а) epithelium stratified squamous nonkeratinized infiltrated b) lamina propria – loose connective tissue with B lymphocytes) ІІ. Submucosa – septae, capsule ІІІ. Muscular tunic skeletal muscle

Tonsil Stratified squamous nonkeratinized epithelium Skeletal muscle Crypt Connective tissue septae Lymph nodules Crypt

Salivary glands major (3pairs) + minor Functions 1. Exocine (saliva secretion) 2. Desinfection 3. Digestion 4. Articulation 2. Endocrine (parotin, VIP, glukagon, kallikrein, renin...) 3. Excretion 4.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

Intercalated ducts Myoepithelial cells Intercellular canaliculi Myoepithelial cells Serous demilunar Mixed acinus Striated duct Intercalated duct Serous acinus Serocytes Mucous acinus Mucocytes Basement membrane

Teeth 1.Functions 2.Structure 3.Deciduous and permanent teeth 4.Enamel 5.Dentin 6.Cementum 7.Pulp 8.Periodontal membrane 9.Development of teeth

Functions 1.Mastication 2.Articulation 3.Esthetic

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

Deciduous teeth (20) 1. Smaller 2. Crown lower and wider 3. Shorter roots Incisors central and lateral Cuspids (canines) Molars Eruption – 6 months- 2 years 12 years Permanent teeth (32) Incisors Cuspids Bicuspids (premolar)s Molars Eruption / /2123

Enamel 1.Covers crown 2.2,5 mm 3.Hardest tissue Chemical composition 1) % – mineral salts (Са hydroxyapatites, fluorides, carbohydrates) 2) 3-4 % – organic substance (fibrillar matrix) MFU – hexagonal enamel rod (S-shaped enamel prism) Retzius, mln in tooth 4-8 мm Enamel rods

Rods are formed by ameloblasts Fur – microorganisms and + mineral and organic substances Pellicle - glycoproteins (II keratinous membrane) Cuticle – ameloblats remnants (I Nasmyth’s membrane) Enamel organ reticulum Apical terminal bar Basal terminal bar RER Tome’s process Golgi complex Nucleus Mitochondria Enamel Secretory granules

Enamel lamellae –thin leaflike structures (septae) Enamel bundles - near dentino- enamel junction Enamel tuft (spindle) Retzius incremental lines Hunter-Schreger bands Dentin Enamel

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)

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) Peritubular dentin Dentin tubules Odontoblast process Dentin cross section Intertubular dentin Dentin tubul Peritubular dentin Intertubular dentin

Dentin Odontoblasts process Odontoblast nucleus Predentin Odontoblasts Pulp

Odontoblast 1.Lies in the pulp 2.Produces dentin 3.Promotes regeneration Dentin tubule Dentin Predentin RER Calcification zone Odontoblast procecss Terminal bar RER GA Mitochondria Odontoblast nucleus

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)

Cementum 1835 two Purkinje pupils 1.Cellular (cementocytes) 2.Acellular Chemical composition % – inorganic substances (Са(РО3)2, СаСО3) % – organic material (collagen fibers and ground substance) % – water Cemento-enamel junction Apical foramen Root Odontoblasts

Pulp – soft tissue Functions 1. Formative 2. Nutritive 3. Sensory 4. Protective In the crown In the root

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

Periodontal membrane (ligament) 1. Formative 2. Supportive 3. Sensory 4. Nutritive Epithelial rests of Malassez (Hertwig’s epithelial root sheath) Cementicles

Parodontum = gingiva + alveola + periodontum Circular ligament (10 ) Periodontum: 1) marginal (4) 2) proper (2)

Developmental stages 1. Dental lamina and bud 2. Enamel organ (cap and bell stage) 3. Histogenesis, organogenesis Tongue Deciduous tooth bud DP Mesenchyme Maxilla Dental papilla Enamel organ Dental Lamina DL Low lip Dental papilla A D C B Enamel organ P Dental papilla P Maxilla Dental sac Low lip Enamel organ Dentin Enamel Pulp DL remnant Dentin Reduced EO Enamel Permanent tooth Dental lamina

Tooth eruption and replacement 1870 Hunter – root growth 1929,1936 Jasvoin – dental pupilla 1940 Kutz – bony tissue +pressure in pupilla Dental sac Enamel organ Enamel Dentin Pulp Dental sac Osteoclasts Dentin Pulp Periodontum Enamel Permanent tooth Pulp Enamel DentinPeriodontum Enamel Dentin Pulp Deciduous tooth Zone of eruption Permanent tooth

Teeth eruption Deciduous (months) No TeethPermanent (years) First molar Incisor central Incisor lateral8-9 3 First premolar Canine/cuspid Second premolar First molar Second molar Third molar 18-25