Oral Mucosa

ORAL MUCOSA •

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Uninterrupted mucous membrane which is continuous with the skin near the vermilion border of the lips and with the pharyngeal mucosa in the region of the soft palate and anterior pillar of fauces • Epithelium of oral mucosa originates from ECTODERM except for TONGUE  ECTODERM

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Taste buds

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Reflexes

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Thirst response

SECRETION o

SALIVA 

3 TYPES OF MUCOSA •

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PERMEABILITY AND ABSORPTION

MASTICATORY MUCOSA o o

Comes in primary contact with food during mastication

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Keratinized

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Areas of free gingiva & attached gingiva; hard palate

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LINING MUCOSA o

Doesn’t function in mastication; has little attrition

o

Soft, pliable & non-keratinized

o

Lips, cheeks, vestibule, floor of the mouth, inferior surface of the tongue, soft palate

Covered largely with cornified epithelial papilla

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Dorsum of the tongue

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Acts as major barrier to surface abrasions and normal flora of the oral mucosa

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o

Irregular and upward projections of connective tissue

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Interdigitates with EPITHELIAL PEGS

RETE PEGS

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Provides considerable information about events within the oral cavity 

Temperature

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Touch

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Pain

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Epithelial pegs/ridges that interdigitates with connective tissue papillae

BASEMENT MEMBRANE o

SENSATION

Underlying connective tissue layer

CONNECTIVE TISSUE PAPILLAE

o

Separates and protects deeper tissues and organs in the oral region

Stratified squamous epithelium

LAMINA PROPRIA/CORIUM o

PROTECTION o

ORAL EPITHELIUM o

FUNCTIONS OF ORAL MUCOSA •

Only for animals like DOGS and not applicable to humans

GENERAL HISTOLOGIC CHARACTERISTICS OF ORAL MUCOSA

SPECIALIZED MUCOSA o

Certain drugs are successfully absorbed when held under the tongue

THERMAL REGULATION o

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Viscous fluid for maintenance of a moist surface

Structureless layer in between connective tissue and epithelium

MUCOPERIOSTEUM o

Provides firm, inelastic attachment of oral mucosa directly to the periosteum of underlying bone without intervening submucosa

o

Binds mucosa to the alveolar process or palatine bone

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STRATUM GRANULOSUM

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Larger flattened cells containing small granules called KERATOHYALIN GRANULES

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FLAGGRIN & LORICRIN proteins

HISTOLOGIC CHARACTERISTIC OF ORAL MUCOSA •

SURFACE EPITHELIUM TYPES o

NON-KERATINIZATION 

STRATUM SUPERFICIALE  •

Slightly more flattened than in the preceding layers

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Contain dispersed tonofilaments and nuclei

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Non-keratinized epithelium

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DESMOSOMES/ INTERCELLULAR BRIDGES

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Slight increase in cell size well as accumulation of glycogen in cells of the surface layer

Cuboidal or columnar cells containing separate tonofilaments and other cell organelles

o

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TYPES: ORTHOKERATINIZATION

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PARAKERATINIZATION

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INCOMPLETE PARAKERATINIZATION

Outermost keratinized layer

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SQUAMES o

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Cuboidal or columnar cells adjacent to the basement membrane

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Aka GERMINATIVE LAYER

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TONOFILAMENTS

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INTERCELLULAR BRIDGES/DESMOSOMES

LAMINA PROPRIA/CORIUM o PAPILLARY LAYER/CONNECTIVE TISSUE PAPILLA  PEGS o

STRATUM CORNEUM •

STRATUM BASALE

ULTRASTRUCTURE OF EPITHELIAL CELLS

Site of most cell division

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Points where the stratum spinosum remain in contact with each other

KERATINIZATION 

Larger elliptical/spherical cells

Flexible and tolerant of both compression and distention

STRATUM BASALE •

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o

STRATUM INTERMEDIUM •

STRATUM SPINOSUM

Interdigitates with RETE

RETICULAR LAYER  Densely arranged connective tissue fibers

Do not contain any nuclei

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-Rosette Go 031909 

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