Week 10 - Histology of Oral Mucosa Regional Variation Flashcards
What are the regional variations of oral mucosa
What are the different types of oral mucosa
Lining mucosa
Masticatory mucosa
Specialized mucosa
What is lining mucosa
Found in areas of the oral cavity that is not subjected to the same mechanical stresses as masticatory mucosa.
Where is lining mucosa found (3)
- lips
-labial and buccal mucosa - floor of the mouth
What is masticatory mucosa
This is the specialized type of oral mucosa that covers the gingiva and the hard palate. This type of mucosa is adapted to withstand the forces generated during chewing (mastication) and protects the underlying structures such as the alveolar bone and teeth.
Where is masticatory mucosa found
- gingiva
- hard palate
what is the example of specialized mucosa
dorsum of the tongue (contains papillae)
Describe the characteristics of labial mucosa
Lining Mucosa
- Non-keratinized
- Lines the inner surface of the lip
- Many mucous glands in the submucosa
- Wide and short papillae
- Connective tissues bind to the underlying orbicularis muscle (muscle of the lip)
What is the muscle of the lip called
orbicularis muscle
Describe the characteristics of the floor of the mouth
Lining Mucosa
- Non-keratinized, thin
- Numerous short papillae and elastic fibers
- Extensive vascular supply (rich blood supply) - hence has a rapid drug absorption
- Irregular and thin submucosa (this can be seen because the floor of the mouth is very thin)
Describe the characteristics of the vermillion zone
Lining mucosa
- Skin on the outside side and the labial mucosa on inner side of the lips
- Mucocutaneous junction connects skin with mucosa
- Translucent keratinized epithelium
- Numerous long narrow papillae
- Capillary loops in the papillae are close to surface - also rich blood supply
- Mucosa firmly attached to the underlying muscle
Describe the characteristics of gingiva
Masticatory Mucosa
- Para-keratinized - may contain nuclei but they are small and shrunken
- Prominent epithelial rete ridges (toughs)
- Slender and long connective tissue papillae
- There is no submucosa, and the lamina propria is directly attached to periosteum (mucoperiosteum)
- Fibers run perpendicular to the surface causing stippling - loss of stippling means that the gingiva is inflamed - there is no stippling if there’s gingivitis
What is stippling
refers to the textured appearance of the gum such like the dimpled surface surface of an orange peel (this is a sign of healthy gingiva)
Describe the characteristics of the hard palate
- Ortho-keratinized/para-keratinized and thick
- No submucosa in the central region
- Lamina propria directly binds to bone (mucoperiosteum) - no submucosa
- Long papillae
- moderately vascular
- Minor mucous gland posteriorly aspect
Describe the characteristics of the dorsum of the tongue
Specialized mucosa
- Functionally masticatory mucosa but it has taste buds
- Anterior 2/3 is covered by numerous papillae
What are the 4 different types of papillae seen on the tongue
- Filiform
- Fungiform
- Circumvallate
- Foliate
Describe filiform papillae
- Thin and cone shaped
- There are the most number of these papillae however they are very small and hard to see
- They are responsible for giving the tongue its texture and are responsible for sensation of touch
- Consist of a central core of lamina propria with smaller papillae branching from it
Describe fungiform papillae
- Isolated, elevated mushroom shaped
- Covered by thin epithelium which may be keratinized or nonkeratinized
- Taste buds may be found
Describe circumvallate papillae
- An anatomical landmark of the tongue as it is a V shaped sulcus terminal which divides the tongue into anterior 2/3 and posterior 1/3
- Located anterior to sulcus terminalis
- Easily seen on the tongue
- Arranged in V shaped
- Covered by non-keratinized epithelium
- Surrounded by a trench like feature
- Taste buds seen in the internal wall of the trench
- Small serous glands (von Ebner) open into the base of the trench. These glands secrete amylase. This digestive enzyme breaks down food.
Describe foliate papillae
- Present at the side of the posterior part of the tongue
- Non-keratinized surface
- May contain taste buds