Oral mucosa

are melanocytes attached to keratinocytes

yes

what is the lining of the stomodeum derived from

ectoderm

What type of epithelium is the epidermis

-stratified squamous epithelium (same as the lining of the oral cavity)

What is the epidermis? What is it derived from

-epithelium of the skin

-ectoderm

Inside the area of mastication has what type of mucosa

masticatory mucosa

is masticatory epithelium keratinized or non keratinized?

keratinized epithelium

which mucosa has a highly fibrous reticular layer

-masticatory mucosa

masticatory mucosa:

bone or muscle?

bone

outside the area of mastication has what type of mucosa

lining mucosa

is lining mucosa keratinized or non keratinized epithelium?

non-keratinized epithelium

lining mucosa:

bone or muscle?

muscle

What features of the oral mucosa and submucosa are similar to our skin

-keratinized epithelium

-normal reticular layer

-muscle

What are the three types of mucosa

-lining mucosa (60%)

-masticatory mucosa (25%)

-specialized mucosa (15%)

Function of oral mucosa

-mechanically protective against both compressive and shearing forces associated with mastication

-provides innate immune barrier to micro-organisms

-role in immunological defense

Is the oral mucosa innervated?

What sensory outputs does it provide?

-yes, richly innervated

-touch proprioception, pain, temp, taste

what mucosa provides an innate immune barrier to micro-organisms, toxins and antigens;

oral mucosa

Does the oral mucosa have salivary glands

yes, secretes saliva

Function of the saliva that is secreted from the salivary glands of the oral mucosa

lubricating and buffering activity

-provides (some) antibodies (sIg's) and germicides.

Function of the mucous film from saliva

-acts as a barrier

-retains water and electrolytes keeping oral cavity moist

Lymphatic tissue of the oral cavity line what

-palatine tonsil

________ = Mucous associated lymphatic tissues

palatine tonsils

What are the first line of adaptive immune defense against pathogens.

palatine tonsils

What are the nodules of the tonsils filled with

B-cells

What occurs at the germinal center of the palatine tonsils

-activated (antigen presented) B-cells become antibody producing plasma cells

Non-keratinocyte cells found in the epithelium (4)

-melanocytes

-Langerhans cells

-Merkel cells

-nerve endings

What are melanocytes derived from

neural crest

what are Langerhans cells derived from

monocytes

what are merkel cells derived from

ectoderm

what are nerve endings derived from

neural crest

What is the lamina propria derived from

ectomesenchyme

what cells are in the lamina propria

-fibroblasts

-collagen fibers

-macrophages (langerhans cells)

origin of submucosa

ectodermal origin

--> exocrine glands

the ectomesenchyme of the submucosa consists of what two things

adipocytes

-connective tissue

what mucosa is soft and pliable

lining mucosa (oral mucosa)

muscosa?

fluids easily injected

lining mucosa (oral mucosa)

mucosa?

lining gapes when cut

lining mucosa (oral mucosa)

mucosa?

inflammation is dispersed

lining mucosa (oral mucosa)

mucosa?

firm and immobile

masticatory mucosa (oral mucoperiosteum)

mucosa?

injections are painful

masticatory mucosa (oral mucoperiosteum)

mucosa?

lining tears when cut

masticatory mucosa (oral mucoperiosteum)

mucosa?

inflammation is painful

masticatory mucosa (oral mucoperiosteum)

prior to tooth eruption what epithelium is para-keratinized?

When does it become keratinized?

masticatory mucosa

- during primary tooth eruption

prior to tooth eruption, what epithelium in non-keratinized

lining mucosa

How does para-keratinized epithelium differ form keratinized epithelium

1. nuclei present in outermost basophilia

2. no distinctive stratum granulosum

3. no stratum corneum

what do stem cells of the oral ectoderm differentiate into

stratum spinosum and stratum basale

Microfilaments and Intermediate filaments of the cytoskeleton in epithelial cells

-actin filaments (microfilament)

-keratin filament (intermediate filament)

what do keratin filaments attach to

-desmosomes

-hemi-desmosomes

cytokeratin found in masticatory mucosa (gingiva)

1, 10

cytokeratin found in lining mucosa (alveolar mucosa)

4, 13

what cytokeratin's are found in both mucosa

5, 14

why do cytokeratin matter

diagnostic to oral cancer

Loss of keratin___ is one of the most valuable diagnostic criteria for discriminating carcinoma in situ (CIS)

13

what are tonofilaments and tonofibrils composed of

cytokeratins

what is the only layer of the masticatory mucosa that undergoes mitosis

-basal layer (stratum Basale)

what is found in the basal layer of keratinized epithelium

-desmosomes

-hemidesmosomes

keratin filaments form tonofibrils

The prickle cell layer (stratum spinosum) of the masticatory mucosa (keratinized epithelium) is made up of what

-heavy keratin fibrils

-desmosomes

What layer of the masticatory mucosa develops the membrane coating granules

-prickle cell layer (stratum spinosum)

What new granule is formed in the granular layer (stratum granulosum) of the masticatory mucosa

-keratohyaline granules (still contains keratin fibrils and desmosomes)

what layer of the masticatory mucosa secretes glycoproteins from MCG

-granular layer (stratum granulosum)

What layer of the masticatory mucosa forms the cornified envelope

-keratinized layer (stratum corneum)

what happens to the cells in the stratum corneum of keratinized epithelium

-all cell organelles are lost

What are the three keratin filament associated proteins (binding proteins)

-where are they found

-filaggrin

-loricrin

-involucrin

(keratinized epithelium - masticatory)

function of filaggrin

binds to and condenses the keratin cytoskeleton (contributes to the cell compaction process that creates the squamous cell shape)

where is filaggrin synthesized and stored

-granular layer and stored in keratohyalin granules

masticatory mucosa is the same as our _____

skin

where is loricrin expressed

Expressed in the superficial layers of keratinized and nonkeratinized oral epithelia

Function of loricrin

Binds to the ends of keratin and contributes towards cornification

Function of involucrin?

Binds to Loricrin and helps to create the cornified "envelope".

________ is due to incomplete removal of organelles from the granular layer.

Para-keratinization (nuclei can still be seen)

(keratinized is the complete removal of organelles)

Layers of the keratinized masticatory mucosa

1. stratum basale (basal layer)

2. stratum spinosum (prickle cell layer)

3. stratum granulosum (Granular layer)

4. stratum corneum (keratinized layer)

layers of non-keratinized epithelium

1. stratum basale (Basal layer)

2. Stratum spinosum (prickle cell layer)

3. stratum intermedium (intermediate layer)

4. stratum superficiale (surface layer)

What is found in the stratum basale of non-keratinized epithelium

-desmosomes

-keratin filaments

-cell divisions

what two layer are found in non-keratinized lining epithelium that is also found in keratinized masticatory mucosa

-basal layer

-prickle cell layer

what layer of non-keratinized epithelium contains the membrane coating granules

prickle cell layer

what layer of non-keratinized lining mucosa contains glycogen vesicles

-stratum intermedium (intermediate layer)

Is there a complete or incomplete removal or organelles in non-keratinized epithelium

-incomplete (this is different from keratinized where all organelles are removed)

what is the importance of the incomplete removal of organelles in the non-keratinized lining mucosa

-Loosely arranged keratin filaments.

-Suface is flexible and tolerant of compression and distension.

melanocytes are what type of cell

dendritic cells that migrate from neural crest into the oral epithelium

what do melanocytes contain

-melanin that is packaged into melanosomes

how is melanin formed

-oxidation of tyrosine - DOPA- Melanin

function of melanosomes

protective shield against UV-radiation

What type of cells are langerhans cells

-antigen presenting dendritic cells

what layer are langerhan's cells present? what is its function?

-Present in Stratum Spinosum

-it scans the epithelium for antigens

what cells present antigens to T-cells

langerhans cells

are langerhan's cells attached to keratinocytes

no (move within the epithelium)

desmosomal attachment of merkel cells

-attached to basal layer of epithelial cells

the cytoplasm of a merkel cell contains what two things

-Keratin filaments (CK20)

-Small granules containing neuropeptides (SP, ViP)

what cell has slowly adapting mechanoreceptors for touch

-merkel's cell

where are merkel cells located

-hard and soft palate

-mandibular gingiva

When do merkel cells increase

-increase under acute inflammation

-substantial increase in chronic inflammation

inflammatory cells in the epithelium

-lymphocytes

-PMN cells (neutrophils) / granulocytes

-plasma cells

what epithelium has a larger number of inflammatory cells

-lining mucosa (non-keratinized)

which type of epithelium has a higher degree of permeability

non-keratinized

Cell Products that form the "Cornified Envelope"

• Keratins

• Glycolipids (from MCG)

• Keratin filament Associated Proteins:

--A. Filaggrin

--B. Loricrin

--C. Involucrin

cell contacts of the barrier

-Intercellular junctions (ex. Desmosomes, Tight junctions)

-Hemi - desmosomes

keratinized vs. non keratinized:

-permeability

-flexibility

-response to abrasion

-keratinized is impermeable (non-keratinized is permeable)

-keratinized is inflexible

-keratinized is resistant to abrasion (non-keratinized is less resistant)

layers of the lamina propria

-papillary layer (loose C.T)

-reticular layer (dense irregular C.T)

principal cell of the lamina propria

fibroblasts

what do the fibroblasts in the lamina propria secrete

-fibers and ground substance

what cell functions in wound healing of the lamina propria

fibroblasts