The Oral Mucosa and Gingivae Flashcards Preview

Oral Biology (Oral Cavity) > The Oral Mucosa and Gingivae > Flashcards

Flashcards in The Oral Mucosa and Gingivae Deck (47)
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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
- 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

1. Masticatory
2. Lining
3. 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
Nerves (probably intrinsic)
Blood vessels


What are the different categories of stratified squamous epithelium



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


What kind of proteins are keratins



Where are a lot of keratins found

Epithelial cells and hair


What are the layers of non-keratinised epithelium

Superficial cells
Stratum Intermedium
Stratum Spinosum
Stratum Germinativum


What are the cells of the stratum intermedium like and how is it different from the stratum granulosum

- Cells become larger, flatter and more mature
- No keratinohyaline granules


What are the cells of the superficial layer like

Nuclei present in cells
Desmosomes disappear, allowing cells to shed off and physiological turnover


What is the basement membrane found between

It is the interface between the epithelium and connective tissue


What is the role of the basal lamina

Provides mechanical adhesion of epithelium to connective tissue and, at the same time, acts as barrier between them


What synthesises the basal lamina

Synthesized by cells of the stratum germinativum


What are the 2 layers of the basal lamina

- Lamina lucida: adjacent to epithelium (laminin)
- Lamina densa: adjacent to connective tissue (collagen IV)


What is the role of hemidesmosomes in the basement membrane

structures on the cell side of basal lamina that link basement membrane to epithelial cells


What is the lamina propria

Connective tissue underlying the epithelium


Describe the collagen fibres in the superficial and deep layers of the lamina propria

Superficial - thin, loosely arranged collagen fibres
Deep - thick parallel bundles of collagen fibres