Oral histology LO 5 part

stratified squamous epithelium

Oral mucosa is this kind of epithelium:

Basement membrane

The ——————— membrane lies between the epithelial and connective tissue layers

Lining mucosa, masticatory mucosa, and specialized mucosa

What are the 3 tissue types within the oral cavity?

Masticatory mucosa

This is the type of mucosa that is on the hard palate and the attached gingiva:

Lining mucosa

This is the type of mucosa that is on the floor of the mouth, ventral surface of the tongue, the cheeks, lips, and soft palate. This mucosa is as a soft surface texture, moist surface, ability to stretch, ability to be compressed, and generally pink/red in colouration. Non keratinized stratified squamous epithelium. The interface between epithelium and connective tissue has relatively less pronounced rete pegs.

Specialized mucosa

This is the type of mucosa that is on the dorsal and lateral surfaces of the tongue.

Stratum superficiale, stratum intermedium, and stratum basale

Within the epithelial layer of the lining mucosa, there are 3 layers of epithelial cells, what are they?

Lamina propria

Connective tissue of oral mucosa

Basal layer

This layer of the lining mucosa is made of cuboidal cells overlying the basement membrane. It is germinative: forms new cells. Attached firmly to basal lamina of the basement membrane. Not always 1 layer.

Intermediate layer

This layer of the lining mucosa is made of large ovoid cells with abundant fluid in the cytoplasm. Thickest layer of the lining mucosa.

Superficial layer

This layer of the lining mucosa is made of flattened cells with small nuclei. The plasma membrane thickens and becomes less permeable. Non keratinized.

Basal lamina (top) and reticula lamina (bottom)

The basement membrane under the electron microscope is made of these 2 layers:

Rete ridges or rete pegs

In the interface between the epithelium and the lamina propria, the downward projections of epithelium are called:

Connective tissue ridges or connective tissue papillae

In the interface between the epithelium and the lamina propria. The upward projections of connective tissue are called:

Papillary layer and dense reticular layer

The connective tissue layer (lamina propria) under the lining mucosa is made of these 2 layers:

Submucosa

This is the layer of lining mucosa that is under the connective tissue layer:

Labial mucosa

This type of mucosa is on the intraoral surface of the lips. Has elastic fibres- the ability to stretch. Lamina propria with seromucous glands. Submucosa- minor salivary glands and adipose CT with obicularis or is muscle.

Vermillion boarder

Junction of the oral mucosa and skin of the lips, blood vessels close to surface in thin area of epithelium.

Nonkeratinized

To examine the lining mucosa of a client, the mucosa is rolled and compressed between the fingers, this is possible because it is ———————— mucosa with a Submucosa.

Masticatory mucosa

This type of oral mucosa is stippled, has as orang peel appearance. Firm and resilient, light pink in colour, immoveable. Keratinized epithelium layer has additional layers of cells. Rete pegs more pronounced giving a firm base. Little or no Submucosa. 4 epithelial layers, the connective tissue layer is made of lamina propria (papillary layer, loose, and dense layer).

Stratum corneum, stratum granulosum, stratum spinosum (prickle cell layer), stratum basale

The masticatory mucosa has 4 epithelial layers, what are they?

prickle cell layer (stratum spinosum)

This epithelial layer of the masticatory mucosa is made up of dehydrated epithelial cells due to loss of fluid. Thickest layer of the epithelium. Cells tend to shrink from each other and remain connected by desmosomes: spiny appearance. Melanocytes are common, langerhans cells: more superficial layers: initiate immune response to pathogens and to cancer.

granular layer (stratum granulosum)

This epithelial layer of the masticatory mucosa is made of flat, stacked cells. 3-5 cell layers deep. Keratohyaline granules (chemical precursor for keratin).

Keratin layer (stratum corneum)

This is the top epithelial layer of the masticatory mucosa. Thin non-nucleated cells. Cells filled with soft keratin (replaces the cytoplasm).

parakeratinized stratified squamous epithelium has a nucleus

The difference between orthokeratinized stratified squamous epithelium (SSE) and parakeratinized SSE, is that parakeratinized SSE has:

Prickle layer

In the oral cavity, masticatory mucosa always contains a ————— layer.

Orthokeratinized SSE

The hard palate is lined with —————————- SSE. Has a thick lamina propria, rugae, and supported by dense lamina propria.

Attached gingiva

Keratinized masticatory mucosa with lamina propria firmly attached to bone.

Papillae

Keratinic extensions of the epithelium. There are 4 types of these on the tongue.

Filiform papillae

This type of papillae is slender, threadlike highly keratinized extensions of epithelial cells. Covers majority of the surface of the tongue 2-3mm height. Gives the dorsal surface of the tongue a velvety texture. No taste buds. Aids in digestion, guiding food to pharynx.

Fungiform papillae

This type of papillae is few in number, near the tip of your tongue. Thin epithelium, less keratinization, highly vascularized LM core. Reddish dots, slightly raised mushroom shaped. 1mm diameter. Taste buds on superficial portion (not near base) function is taste sensation.

Circumvallate papillae

7-15 large raised, mushroom shaped structure anterior to the sulcus terminalis. V shaped row facing pharynx. 3-5 in diameter.

Foliate papillae

These papillae are on the lateral posterior part of the tongue. 4-11 vertical grooves. Taste buds. Serous glands underlying the taste buds which cleanse. Function is taste sensation.

Taste buds

Barrel shaped epithelial structure. Supporting cells and taste cells. Taste cells with elongated microvilli into taste pore. Sensory nerve innervation. Turnover time: 10 days.

Nasal cavity

The ————— ————— is the inner space of the nose. It communicates with the exterior by 2 nares. The nares are separated by the midline nasal septum.

Nasal conchae

Each lateral wall of the nasal cavity has 3 projecting structures, or nasal —————, which extend inward.

Paranasal sinuses

The ——————— sinuses are paired air-filled cavities in bone that include the frontal, sphenoidal, ethmoid, and maxillary sinuses.

Sinusitis

The respiratory mucosa of the nasal and paranasal sinuses can become inflamed and the space congested with mucosa as a result of allergies or respiratory tract infection. This inflammation can lead to a stuffed-up feeling in the nasal cavity and ——————— in the sinus.