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Non-KeratinocytesNon-Keratinocytes

Group 4Group 4 Under supervision of Under supervision of Dr:Hany gamilDr:Hany gamilOral Histology DepartmentOral Histology DepartmentFaculty of DentistryFaculty of DentistryAl-Azhar UniversityAl-Azhar University

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Non-KeratinocytesNon-Keratinocytes It constitutesIt constitutes 10 % of population in the oral 10 % of population in the oral

epithelium.epithelium. It contains 4 types of cellsIt contains 4 types of cells..1.1. Melanocytes.Melanocytes.2.2. Langerhans cells.Langerhans cells.3.3. Merkel cells.Merkel cells.4.4. Inflammatory cells.Inflammatory cells.

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11 . .MelanocytesMelanocytes Shape Shape : Denderitic cell with marked variations : Denderitic cell with marked variations

in cell size.in cell size. Origin Origin : Neural crest cells.: Neural crest cells. Site Site : Basal layer of epithelium, and its : Basal layer of epithelium, and its

dendrites in suprabasal layer.dendrites in suprabasal layer. FunctionFunction : Synthesis of melanin pigments : Synthesis of melanin pigments

which is packed in melanosomes.which is packed in melanosomes.

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MelanocytesMelanocytes Number of melanocytes Number of melanocytes

in oral epithelium is the in oral epithelium is the same in all persons.same in all persons.

Color of oral mucosa is Color of oral mucosa is affected by masking affected by masking effect of heavily effect of heavily keratinized epithelium keratinized epithelium and the degree of and the degree of vasculature.vasculature.

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22 . .Langerhans CellLangerhans Cell ShaepShaep : Denderitic cell. : Denderitic cell. OriginOrigin : Bone Marrow : Bone Marrow SiteSite : Suprabasal layer of epithelium, and its : Suprabasal layer of epithelium, and its

dendrites in basal layer.dendrites in basal layer. FunctionFunction : Acts as antigen presenting cell, It is : Acts as antigen presenting cell, It is

the outermost arm of immune system.the outermost arm of immune system.

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Langerhans cellsLangerhans cells Langerhans cells probably Langerhans cells probably can migrate fromcan migrate fromepithelium to regional epithelium to regional lymph nodeslymph nodes..

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33--merkel cellmerkel cell ShapeShape: non-dendritic : non-dendritic

cell, posses cell, posses desmosomes and desmosomes and tonofilaments.tonofilaments.

OriginOrigin: epidermal cells.: epidermal cells. SiteSite: basal layer.: basal layer. FunctionFunction: respond to : respond to

touch.touch.

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Merkel cellMerkel cell Each cell is related to a nerve fiberEach cell is related to a nerve fiber Merkel cell posses a small membrane bound Merkel cell posses a small membrane bound

vesicles in the cytoplasm, These granules may vesicles in the cytoplasm, These granules may liberate a transmitter substance across the liberate a transmitter substance across the synapse-like junction between the Merkel cell synapse-like junction between the Merkel cell and the nerve fiber and thus trigger an impulse.and the nerve fiber and thus trigger an impulse.

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44--inflamatory cellsinflamatory cells They are transient cells associated with They are transient cells associated with

inflammatory response of oral mucosainflammatory response of oral mucosa OriginOrigin: blood: blood SiteSite: found at various levels of the epithelium : found at various levels of the epithelium

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Differences between keratinocyte & Differences between keratinocyte & Non-keratinocyteNon-keratinocyte..

KeratinocytesKeratinocytesNon_KeratinocytesNon_Keratinocytes

Always present inAlways present in layers layersPresent as Present as scattered cellsscattered cellsContains tonofilamentsContains tonofilamentsFree from tonofilaments Free from tonofilaments

except merkel cellexcept merkel cellHave desmosomal Have desmosomal junctionsjunctions

Do not have desmosomal Do not have desmosomal junctions except merkel junctions except merkel cellcell

Synthesize KeratineSynthesize KeratineDo not synthesize KeratineDo not synthesize KeratineHighHigh mitotic activitymitotic activity and and

renewalrenewal. . Low Low mitoticmitotic activityactivity. .

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Specialized mucosaSpecialized mucosa

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Specialized mucosaSpecialized mucosa Present on the dorsal Present on the dorsal

surface of the tongue , surface of the tongue , which is divided by which is divided by v_shaped sulcus v_shaped sulcus terminalisterminalis into papillary into papillary part (ant. 2/3part (ant. 2/3 ( (and and lymphatic part (lymphatic part (post.1/3).post.1/3).

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Anterior 2/3Anterior 2/3 Atnerior 2/3Atnerior 2/3 of the toung contain of the toung contain 4 types of4 types of

papillaepapillae : :1-1-filiformfiliform papillae papillae2-2-fungiformfungiform papillae papillae3-3-circumvallatecircumvallate papillae papillae4-4-foliatefoliate papillae papillae

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11--Filiform papillaeFiliform papillae Site: Site: cover the entire anterior part of the tongue.cover the entire anterior part of the tongue. Shape:Shape: cone cone--shaped .shaped . Histology:Histology: core of connective tissue covered by a core of connective tissue covered by a

thick keratinized epitheliumthick keratinized epithelium FunctionFunction: : 1-1-protection of the fungiform papillaeprotection of the fungiform papillae2-2-compressing and breaking food when the tongue is compressing and breaking food when the tongue is

apposed to the hard palate. Thus the dorsal mucosa of apposed to the hard palate. Thus the dorsal mucosa of the tongue functions as a masticatory mucosa.the tongue functions as a masticatory mucosa.

3-have no test buds3-have no test buds

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Filiform papillaeFiliform papillae

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22--fungiform papillaefungiform papillae Site:Site: in the anterior part of the tongue scattered in the anterior part of the tongue scattered

between the numerous filiform papillae.between the numerous filiform papillae. Shape:Shape: mashroom like apperance. mashroom like apperance. Histology :Histology : central core of central core of highly vascularhighly vascular

C.T. covered by a thin layer of non- C.T. covered by a thin layer of non-keratinized epithelium keratinized epithelium

Function:Function: contain test buds contain test buds

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fungiform papillaefungiform papillae

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33--circumvallate papillaecircumvallate papillae Site:Site: anterior to sulcus terminalis . anterior to sulcus terminalis . Shape:Shape: large structures each surrounded by a deep, circular large structures each surrounded by a deep, circular

groove, they do not protrude above the surface of the tounge.groove, they do not protrude above the surface of the tounge. Histology:Histology:

connective tissue core that is covered on the superior surface connective tissue core that is covered on the superior surface by a keratinized epithelium. The epithelium covering the by a keratinized epithelium. The epithelium covering the lateral walls is non-keratinized and contains taste buds, in the lateral walls is non-keratinized and contains taste buds, in the base of the groove there is ducts of minor salivary glands (base of the groove there is ducts of minor salivary glands (the the glands of Ebner) glands of Ebner) which have the following function:which have the following function:

1-1-cleansecleanse the food depris the food depris 2-2-DissolvingDissolving the food to help taste sensation . the food to help taste sensation . 3- in infant secrete 3- in infant secrete lipase enzymelipase enzyme . .

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circumvallate papillaecircumvallate papillae

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44--foliate papillaefoliate papillae Rare in human Rare in human Present in RatPresent in Rat

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Taste budsTaste buds Present in :Present in :1- papillae thexcept filiform . 1- papillae thexcept filiform .

All tongueAll tongue2- soft palate .2- soft palate .3- posterior surface of 3- posterior surface of

epiglottis .epiglottis . Shape :Shape : ovoid with rounded ovoid with rounded

base toward the connective base toward the connective tissue and pointed end at the tissue and pointed end at the outer surface. outer surface.

..

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Taste seneationTaste seneation

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Taste sensationTaste sensation

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