histology of the eye
TRANSCRIPT
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Endre Dobó
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> fibrous coat> cornea> sclera
> vascular coat / uvea> choroid> ciliary body> iris
> nervous coat / retinal layer> as to the development
> neural layer> pigment epithelium
> as to the structure> blind part of retina> (ora serrata)> optic part of retina
> retina proper
blind part of retina[1+1 layers]
ora serrata[boundary; 9 layers reduced to 1 here]
optic part of retina[1+9 layers]
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main layers:> fibrous coat / corneoscleral layer (tunica fibrosa)
> cornea> (corneo-scleral junction)> sclera
> vascular coat / uveal layer (tunica vasculosa bulbi / uvea)> choroid> ciliary body (corpus ciliare)> iris
> sensory coat / nervous layer (tunica nervosa bulbi)> as to the development of the eyeball
> neural layer (str. cerebrale)> pigment layer (str. pigmentosum / str. pigmenti retinae)
> as to the anatomical structure> blind part (pars coeca retinae)> (ora serrata)> optic part (pars optica retinae)
> retina proper
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retina
choroid
sclera
extra-ocular muscle
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layerlayer ofof thethe afferentafferent fibersfibers (9.)(9.)
ganglionganglion cellcell layerlayer (8.)(8.)
innerinner nuclearnuclear layerlayer (6.)(6.)
outerouter nuclearnuclear layerlayer (4.)(4.)
rodrod andand conecone processesprocesses (2.)(2.)
pigment pigment cellscells (1.)(1.)
choroidchoroid
sclerasclera
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> anterior one-sixth of the this main layer> transparent> its junction with the conjunctiva: limbus> sensory innervation by long ciliary nerves [n. V/1]> lacks vasculature (!)> layers
> corneal epithelium (epithelium corneae / epithelium anterius corneae)> stratified squamous epithelium
> underneath, there are no connective tissue papillae> free nerve endings from ophthalmic nerve [n. V/1.]
> Bowman's membrane (lamina limitans anterior / membrana limitans anterior)> acidophil, cell-free membrane> if injured, it loses its transparency
> substantia propria corneae> stroma> keratocytes> highly regular form of dense collagenous tissue
> Descemet's membrane (lamina limitans posterior)> acidophil basement membrane
> corneal endothelium / corneal mesothelium (endothelium camerae anterioris)> simple squamous epithelium
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> posterior five-sixths of the this main layer> opaque> contains few blood vessels> provides insertion for the extra-ocular muscles> layers
> lamina fusca sclerae> thin layer with occasional melanocytes> may be considered articial layer on the inner surface of sclera
> scleral stroma> densely collagenous, hypocellular tissue with elastic fibers
> episcleral layer> connected with Tenon's capsule by fine delicate collagenous fibers
> important anatomical part> lamina cribrosa
> perforated layer of the slcera for the passage of optic nerve fibers
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> from external view> conjunctival ring
> beginning of the conjunctiva of the eyeball> scleral sulcus
> in the middle"> limbus corneae (corneoscleral junction)
> from internal view> Descemet s membrane terminates, and trabecular meshwork begins> iridocorneal angle (angulus iridocornealis)
> trabecular meshwork (spongiosa sclerae)> drainage of aqueous humor (humor aquosus)> parts
> trabecules / pectinate ligaments> spaces of Fontana (spatia anguli iridocornealis)
> there is NO endothelial lining> is not continuous with the canal of Schlemm
> canal of Schlemm (sinus venosus sclerae / canalis Schlemmi)> single circular vessel, lined by endothelium> minute channels (venae aquosae) through the sclera lead to the episcleral venous
system
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corneal epithelium
conjunctival ring
substantia propria corneae
Descemet s membrane
iridocorneal angle
trabecular meshwork
canal of Schlemm
ciliary epithelium
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> layers
> suprachoroidal lamina (lamina suprachoroidea)
> contains only a few vessels and pigment
> houses the ciliary nerves, posterior ciliary arteries and the vorticose veins
> perichoroidal space (spatium perichoroideale)
> spatial system, part of which forms lymph pathways
> vascular lamina (lamina vasculosa / lamina vascularis)
> precapillary arterioles and postcapillary venules
> choriocapillary layer (lamina choroidocapillaris / lamina choriocapillaris)
> network of fenestrated capillaries
> Bruch's membrane (lamina vitrea / lamina basalis)
> double layer of basement membranes
> blood-retina barrier
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> anatomical structure
> orbiculus ciliaris (pars plana)
> ciliary m. (m. ciliaris)
> fibrae meridionales
> fibrae radiales
> fibrae circulares
> corona ciliaris (pars plicata)
> ciliary folds (plicae ciliares)
> ciliary processes (processus ciliares)
> aqueous humor (humor aquosus) is secreted here
> zonula ciliaris [lencse függeszt készüléke]
> suspensory ligament of Zinn (fibrae zonulares)
> attached to the coronal equator of the lens
> histological structure
> stroma corporis ciliaris
> loose connective tissue, with capillary network and ciliary muscles
> epithelium (pars ciliaris retinae)
> outer layer is pigmented
> inner layer is NOT pigmented
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stromastroma corporiscorporis ciliarisciliaris
epitheliumepithelium ciliareciliare
outerouter pigmented pigmented layerlayer
innerinner NOT pigmented NOT pigmented layerlayer
ciliaryciliary processesprocesses
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> anatomical structure> pupillary margin (margo pupillaris)
> lesser arterial circle of iris (circulus arteriosus iridis minor)> ciliary margin (margo ciliaris)
> greater arterial circle of iris (circulus arteriosus iridis major)> pectinate ligaments (ligamenta pectinata)
> among them: spaces of Fontana (spatia anguli iridocornealis)> histological structure
> anterior surface (endothelium camerae anterioris)> discontinuous epithelium, intermingled with melanocytes and fibrocytes
> stroma iridis> constrictor m. of the pupil (m. sphincter pupillae)
> innervated by parasympathetic fibers from the oculomotor n.> pigmented cells (melanocytes)> dilator pupillae m. (m. dilatator pupillae)
> smooth muscle cells (neuroectodermal by origin) or> pigmented (!) myoepithelial cells> innervated by sympathetic fibers from the carotid plexus)
> (membrana limitans iridis)> membrana basalis
> pigmented epithelium (str. pigmenti iridis / str. pigmentosum / pars iridica retinae)> bilayered epithelium
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endotheliumendothelium cameraecamerae anteriorisanterioris
stromastroma iridisiridis
melanocytesmelanocytes
sphinctersphincter pupillaepupillae m.m.
dilatatordilatator pupillaepupillae m.m.
pigmented pigmented epitheliumepithelium
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> parts - as to the development> neural retina (str. nervosum / str. cerebrale retinae)
> 9 inner histological layers> pigment epithelium (str. pigmentosum retinae)
> 1 layer simple epithelium, which is pigmented
> parts - as to the anatomy> light-INsensitive part (pars coeca retinae)
> contains NO photoreceptors
> pars ciliaris retinae> pars iridica retinae
> (ora serrata - ora serrata)
> here reduce the 10 layers into 2 cell layer of parscoeca
> light-sensitive part (pars optica retinae)> contains photoreceptors (rodes and cones)
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> (1) > str. pigmentosum / str. pigmenti retinae (pigment epithelium)> pigmented epithelium
> (2) > str. neuroepitheliale / str. bacilli et coni (rod and cone processes)> processes of light-sensitive cells: rods (bacilli) and cones (coni)
> (3) > str. limitans externum / membrana limitans externa (outer limiting membrane)> formed by Müller cells (glial cells)
> (4) > str. granulosum externum / str. nucleare externum (outer nuclear layer)> somata of the photoreceptor cells
> (5) > str. plexiforme externum (outer plexiform layer)> between the receptor cells and bipolar cells> between the horizontal cells and receptor cells
> (6) > str. granulosum internum / str. nucleare internum (inner nuclear layer)> neurons: bipolar and horizontal neurons, amacrine cells> cell bodies of Müller cells
> (7) > str. plexiforme internum (inner plexiform layer)> between the bipolar neurons and ganglion cells
> (8) > str. ganglionare (ganglion cell layer)> ganglion cells
> (9) > str. neurofibrarum (layer of the afferent fibers)> unmyelinated optic nerve fibers> here branch the retinal central blood vessels
> (10) > str. limitans internum / mebrana limitans internum (inner limiting membrane)> formed by Müller glial cells; demarcates the innermost aspect of the retina from the
vitreous body
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> principal refracting media of the eye> cornea> lens of eye (lens crystalina)
> non-refracting optical media of the eye> aqueous humor (humor aquosus)> vitreous body (corpus vitreum)
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> ciliary process of ciliary body
> posterior chamber
> anterior chamber
> spaces of Fontana of the trabecular meshwork
(between the pectinate ligamants)
> canal of Schlemm (sinus venosus sclerae)
> venae aquosae (small-caliber blood vessels)
> episcleral veins
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> bulbar conjunctiva (conjunctiva bulbaris / conjunctiva bulbi)
> continuous with the cornea
> non-keratinized stratified squamous epithelium
> connective tissue papillae
> lamina propria
> (conjunctival fornix [fornix conjunctivae [reflection])
> stratified columnar epithelium
> palpebral conjunctiva (conjunctiva palpebralis / conjunctiva palpebrae)
> stratified columnar epithelium
> close to the fornix
> goblet cells occur in the outermost layer (!!!)
> non-keratinized stratified squamous epithelium
> close to the anterior palpebral edge
> small lacrimal glands may appear in the entire conjunctiva
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> elastic biconvex structure
> structure
> lens capsule (capsula lentis)
> 10-20-mikrometer thick membrana basalis
> anterior surface
> subcapsular epithelium (epithelium anterius)
> single cuboidal epithelium
> (lens equator)
> posterior surface
> lens fibers (fibrae lentis)
> epithelial cells
> losing their nuclei: anucleate fibers
> stretch between the anterior and posterior poles of the lens
> contain crystalline protein
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the eye is partioned by the lens, suspenssory ligament and ciliary body into:> smaller anterior compartment
> filled with aqueous humor> watery fluid, hypotonic with respect to plasma> secreted by the ciliary processes of ciliary body> source of nutrients for the non-vascular lens and cornea
> parts> anterior chamber (camera bulbi anterior)
> bordered by cornea, iris and lens> posterior chamber (camera bulbi posterior)
> bordered by lens, suspensory ligament and ciliary body> large posterior compartment
> contains vitreous body> gelatinous mass> consisting of vitreous humor
> 99% is water & hyaluronic acid> hyaloid canal / Cloquet s canal (canalis hyaloideus)
> hyaloid artery during embryological development> vitreous membrane / hyaloid membrane
> condensation of fibers on the surface of the vitreous body