The Oral Mucosa and Gingivae Flashcards
What are the functions of the oral mucosa
- Mechanical protection against both compressive and shearing forces
- Barrier against bacteria, toxins, antigens
- Immunological defences (humoral and cell-mediated
immunity) - Contains minor salivary glands that lubricate the mucosa
- Innervation (sensory nerve endings for touch, pain, taste)
What are the 3 functional classes of the oral mucosa
- Masticatory
- Lining
- Specialised
Where is the masticatory mucosa found, is it keratinised and describe its lamina propria
- in areas of high compression and friction
- gingivae, hard palate
- highly keratinized and thick lamina propria
Where is the lining mucosa found, is it keratinised and describe its lamina propria
• in areas that must be mobile and distensible
• cheeks, lips, alveolar mucosa, floor of mouth, ventral
surface of tongue, soft palate
• non-keratinized and loose lamina propria
Where is the specialised mucosa found
- dorsal surface of the tongue (because of taste buds)
* vermilion of lips (transition between skin-oral mucosa)
What kind of epithelium is in the oral mucosa
Stratified Squamous epithelium
What are the properties/features of the Lamina Propria
Connective tissue
Mainly fibroblasts
ECM rich in collagen
Capillaries and nerve endings
Where is the sub-mucosa and what does it consist of
Under the muscularis mucosa Loose CT Fat deposits Glands Nerves (probably intrinsic) Blood vessels
What are the different categories of stratified squamous epithelium
Keratinised
Non-keratinised
Parakeratinised
What is the surface of keratinised epithelium made of and what is it filled with
Surface made of non-viable cells without nuclei, filled with keratins (stratum corneum)
What is the surface of non-keratinised epithelium made of
Surface consists of all viable cells with nuclei
What is the surface of parakeratinised epithelium made of
Surface made of some non-viable cells without nuclei, and some apoptotic cells with shrivelled nuclei
What are the different layers of the keratinised epithelium
Stratum Corneum - keratinised layer
Stratum Granulosum - granular layer
Stratum Spinosum - prickle cell layer
Stratum Germinativum - stratum basale or basal layer
What does the stratum germinativum (basale) contain a lot of and what is its role
- Contains a lot of progenitor cells
- Gives rise to the epithelial layers above it
What are the cells of the stratum spinosum like and what is its role
- Prickly (spinous), Larger and rounder cells, connected by desmosomes
- Produces keratins that are resistant fibrous cytoskeletal proteins that are composed of intermediate filaments (found in all epithelia)
What are the cells of the stratum granulosum like and what granules can be found
- Cells become larger, flatter and more mature in this layer
- Cytoplasm gradually fills with keratinohyaline granules
What are the cells of the stratum corneum like and what is this layer’s role
- Cells lose all organelles and completely fill with keratins.
- Provides mechanical protection to the mucosa
What allows the stratum corneum cells to shed off for the physiological turnover of epithelial tissue
The desmosomes disappear