HISTOLOGY OF THE EYE
BatariTodjaUmar
THE EYE
Spherical structure, 25 mm in diameter
Suspended in the bony orbital socket 6 extrinsic muscles
Wall of the eye 3 concentric layers
Fibrous tunic
Vascular tunic
Nerve tunic
SCLERA
Athickfibrouslayer,coverstheposterior5/6of
theeyeball
Dividedinto3layers:
Episclera
Externallayer
Looseconnectivetissueadjacenttotheperiorbital
fat
Stroma(Substantiapropria)
=Tenonscapsule
Composedofdensenetworkofthickcollagenfibers
LaminaFushcae
Inneraspect,adjacentto
thechoroid
Containsofthinner
collagen&elasticfibers
Melanocyte
Function:
Protects&maintains
theshapeandthe
volumeoftheeyeball
Corneoscleral Limbus
Transitionalzone
betweenthecornea&
sclera
1.52mmwide,1mm
thick
Iridocornealangle
apparatusfortheoutflow
oftheaqueoushumor
trabecularmeshwork
Cornea
Transparent,0.5
mmthickatthe
center,avascular,
5layers
Cornealepithelium
Nonkeratinizing
squamousepithelium
Basalcelllayergivesrise
to57superficiallayers
Freenerveendings
terminateinthis
epithelium
Adherestotheadjacent
cellsbydesmosomes
BowmansMembrane
810mthick
Composedoffinecollagen
fibrils
Barriertothespreadof
infection
Notregenerate
Cornealstroma
Constitutes90%ofthe
cornealthickness
Composedofabout60thin
lamellae
Eachlamellaeconsistof
parallelbundlesofcolagen
fibrils
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decompressor
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Descemetmembrane
Basallaminaof
endothelialcells
Homogen
Elastic,transparent
710m
Cornealendothelium
Asinglelayerof
squamouscells
Metabolicexchange
betweenthecornea&
aqueoushumor
Preciseregulationofthe
watercontentofthe
stromamaintainthe
transparency
Physical&metabolic
changescornealswelling
IRIS
Themostanteriorpartofthevasculartunic,forms
acontractilediaphragminfrontofthelens,a
circularapperture(pupil)changesinsizein
responsetothelightintensity.Eyecolouris
determinedbytherelativenumberofmelanocytes
Composedof4layers
Anteriorlimitingmembrane
Fibroblastic&melanocytecells
Stroma
Loosefibrocollagenoussupporttissue
Bloodvessels,nerve,melaninpigment
Sphinctermuscleofthepupil
Epitheliallayer
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Anteriornonpigmented
epithelium
Dilatorpupillaemuscle
Posteriorpigmentepithelium
Facestheposteriorchamberoftheeye
Cilliary Body
Triangularshape
Extendsfromthebaseoftheiristotheora
serrata
2anatomicalregions
Parsplica
Parsplana
Function:
Aqueoushumorproduction
Acomodationprocess
Thelayersaresimilartothe
iris
Consistof:
Stroma
Outerlayerofsmooth
musclecilliary
muscle
Meridional
(longitudinal
portion)
Radial(oblique
portion)
Circularportion
Innervascularregion
extendsintothe
cilliaryprocess
Continuouswith
thevascularlayer
ofthechoroid
Epitheliallayers
3principalfunctions
Secretionofaqueoushumor
Paticipationinbloodaqueousbarrier
Secretion&anchoringthezonulafibers
Theinnercellslayernonpigmented
Theoutercellslayerpigmented
CHOROID
Darkbrownvascularsheet,
0.25mmthickposteriorly,
0.1mmthickanteriorly
Liesbetweenthesclera&
retina
Supportstheretina
Containsof:
Suprachoroidlamina
30mthick
Looseconnectivetissue
Choroidalstroma
Numerousvenules&
arterioles
Hallerlayer(outerpart)
Sattlerlayer(innerpart
Choriocapillary
4.
Capillarylayersupportingthedeeplayeroftheretina
Diameter4060m
Thinwall
Bruchsmembrane
14mthick
Interfacebetweenthechoroid&theretinalpigmentepithelium
RETINA
10layers
1. Retinalpigmentepithelium
2. Photoreceptorcells
3. Outerlimitingmembrane
4. Outernuclearlayer
5. Outerplexiformlayer
6. Innernuclearlayer
7. Innerplexiformlayer
8. Ganglioncells
9. Nervefiberlayer
10. Innerlimitingmembrane
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Retinal Layers
Retinal Pigment Epithelium
Photoreceptor cells
REFRACTIVE MEDIA OF THE EYE
LENS
Transparent,avascular,biconvex
Suspendedbetweentheedgesof
cilliarybodyzonulafibers
9mmindiameter,3.5mmthick
Capsule
Athickbasallamina
Producedbytheanteriorlenscells
Subcapsularepithelium
Cuboidallayerofcells
Onlyontheanteriorsurfaceofthelens
Lensfibers
Derivedfromsubcapsularepithelial
cells
VitreousBody
Betweenthelens&theretina
Transparentgelatinousstructure
Attachtothesurroundingstructures
Mainportionishomogenousgelcontaining99%water,
collagen,hyaluronateacid
Avascular
ACCESORY COMPONENTS OF THE EYE
Conjunctiva
Atranslucentmembrane
Extendsfromcorneosclerallimbusinternalsurfaceof
theeyelid
2layers
Stratifiedcolumnarepithelium
Gobletcellsmucin
Laminapropria
Looseconnectivetissue
Bloodvessels&lymphaticvessels
Palpebra
Upper&lowereyelid
Protectionoftheeye
Containsof:
Skin
Orbicularisoculimuscle
Tarsalplate
Conjunctiva
Glands
Meibomianglands
Sebaceoustype
Oilylayerofthetear
film
Embeddedinthetarsal
plate
GlandsofZeis
Sebaceousglands
GlandsofMoll
Apocrinesweatglands
GlandsofKrause
Fornixconjunctiva
GlandsofWolfring
Abovethetarsalplate
Lacrimalapparatus
Lacrimalglands
Upperlateralsideofthe
orbit
2parts:orbital&palpebral
parts
1020ducts
Severalseparatelobulesof
tubuloacinarserousglands
Drainsintotheupperfornix
Washoverthesurfaceof
theeye
Tearsdrainfromtheeye
throughlacrimalpuncta
Lacrimalcanaliculiatmedial
angle,
Mergeintocommonlacrimal
duct
Openintolacrimalsac,
pseudostratifiedciliated
epithelium
Continuoustonasolacrimal
ductopentonasalcavity
belowtheinferiorturbinate
