Oral Mucosa Flashcards
(55 cards)
What type of epithelium does the oral mucosa consist of?
Stratified squamous epithelium (both keratinized and non-keratinized)
How does the type of illness affect the way the illness look in the oral cavity?
When there is increase in sickness the epithelium looks whitish.
When there is a decrease in sickness the epithelium looks less white.
This is due to keratin layer being affected. (Eg. squamous cell carcinoma)
What are the roles of the oral mucosa?
It is protective against both compressive and shearing forces
Barrier function
Immunological defense
Lubrication, buffering, and secretion of antibodies
Input for touch, proprioception, pain, and taste (highly innervated
What are the 3 components of the oral mucosa?
Epithelium
Lamina propria
Sub-mucosa
What body system is the oral mucosa a part of?
Oral mucosa is part of the mucosa covering the alimentary tract
What are the histological layers of the oral mucosa?
Oral epithelium
Basement membrane
Lamina propria consisting of basal and papillary layer + a dense fibrous layer
Submucosa
How is epithelium attached to the connective tissue?
By a basement membrane and they are attached to each other.
Where is epithelium derived from embryologically?
Ectoderm or endoderm.
What does the lamina propria consist of?
Dense connective tissue
Submucosa (looser connective tissue)
What happens if the adhesive junctions in oral mucosa is defective?
This leads to a condition called pemphigous. Defect is seen between cells.
How is pemphigous treated?
Via use of corticosteroids
What causes pemphigo?
Pemphigo occurs when anchoring fibrils are defective between the cells of the basement membrane and reticular fibers.
What are the layers of the epithelium of the oral mucosa?
Stratum germinativum
Stratum spinosum
Stratum granulosum
Stratum corneum
What are the types of layers of epithelium?
Pyknotic layer
Maturing layer
Basal layer
Basement membrane
What cells are seen in the stratum germinativum/basale?
Single cell layer adjacent to the lamina propria
Cuboidal cells, progenitor cells, give rise to cells in epithelial cells above
A minority are true stem cells
Non-keratinocytes may be found in the stratum germinativum
Why does the oral mucosa heal faster than the rest of the body?
Because of the quality of the cells in the stratum basale (mitotic index high)
What happens in the stratum spinosum?
Consists of round or ovoid cells
First stages of maturation is present here from the stratum basale. They are rounder and larger than the startum basale.
Desmosomes
Parabasal layer is the layer adjacent to the basal layer
What is contained in the stratum granulosum?
Many organelles are reduced or lost, cells are larger and flatter/ Contain keratohyaline granules.
Membrane-coating granules discharge into the extracellular space.
Development of a barrier in the epithelium that limits the movement of substances between the cells.
What is contained in the stratum corneum?
Final stage of maturation
Epithelial squamas (shed via desquamation)
Mechanical protective function to the mucosa
Ortho or parakeratinized
In lining epithelium the epithelial cells are non-keratinized at the surface
What is the principle cell in the oral epithelium?
The keratinocyte which are rapidly renewing, terminally differentiated cells with cytoplasmic filaments, cell envelopes, and specialized cell junctions
What are cytokeratins?
a type of intermediate filament
What si the cytoskeleton composed of?
Micro and intermediate filaments
Microtubules
Why are cytokeratins so important?
Cytokeratins are specific to different types of epithelium and this is useful because antibodies can be used to visualize these layers
How many cells of the oral epithelium are non-keratinocytes?
Up to 10%
