Eye Iris%20 pupil iris ciliary body ilayers FIBROUS VASCULAR NEURAL Eyeball Eyeball Eyeball in LM eyeball anterior segment posterior segment Eyeball Three layers of the eye 1.Multilayer inner retina 2.Middle choroid – pigmented, vascular 3.Outer sclera – dense fibrous c . t. Fibrous tunic - tunica externa oculi nCornea n – HP_img6-19-1 Sclera Cornea •Stratified squamous epithelium •Bowman´s membrane-anterior limiting lamina •Substantia propria cornae -200 - 250 layers of regularly organized collagen fibrils -fibrocytes /keratocytes/ •Descemet´s membrane-posterior limiting lamina -the basement membrane of the posterior endothelium •Posterior endothelium -simple squamous epithelium n cor20he Cornea HP_img6-19-2 Vascular tunic - tunica media oculi •Choroid –- loose c.t. with network of blood vessels, numerous pigment cells •Ciliary body –- loose c.t. with smooth muscle cells – musculus ciliaris /accomodation/ –- ciliary processes – generate aqueous humor •Iris –- central opening of the iris - the pupil HP_img6-19-1 ch c i Choroid •Lamina suprachoroidea /lamina fusca sclerae/ •Lamina vasculosa •Lamina chorocapillaris •Lamina vitrea /Bruch´s membrane/ choroid sclera retina choroid Choroid oko4 Ciliary body - structure HP_img6-19-3 ciliary epithelium - outer cell layer is pigmented, whereas the inner cell layer is nonpigmented /pars caeca retinae/ m. ciliaris ciliary processes Ciliary body ciliary body nTwo functions –- accomodation –- production of the aqueous humor –ACCOMODATION –from the ciliary processes extend fibers towards the lens - fibres are called zonular fibres –contraction of the m. ciliaris reduces the tension of the zonule fibres and result in a thickening of the lens which focusses on close objects - accomodation Image_000184A aq humor production of the aqueous humor Ciliary processes Image_000188A oko5 Iris nAnterior epithelium –discontinued layer nAnterior border layer –pigment cells nStroma iridis –gelatinous c.t., numerous pigment cells –surrounds the pupil are smooth muscle cells which form the annular sphincter pupillae muscle nPosterior border layer –m. dilator pupillae /myoepithelial cells/ nPosterior epithelium –one layer pigmented cells HP_img6-19-4 colour of the eyes pars iridica retinae Retina ilayers ora serrata Retina (neural tunic) – cell types nPigment cells nNeurons –1st neuron = rod cells and cone cells –2nd neuron = bipolar cells –3rd neuron = ganglion cells (multipolar) –interneurons §horizontal cells §amacrine cells nNeuroglia –Müller cells – occupy practicly the entire retina, part between outer and inner limiting membrane (which are formed by their cell bases) n retina3 Sclera – Choroidea - Retina oko7 Retina ret inner limiting membrane 10 layers Retina HP_img6-19-5 light Retina - fovea centralis Bez názvu maximal visual acuity only cone cells Retina - discus nervi optici Image_000178A eyeball optic disc - blind spot sclera Retina retina Refractive media nCornea nAqueous humor nLens nVitreous body n n Refractive media are characterized by high transparency and refractivity. anatomy Lens lens The lens fibers are highly specialized cells that differentiate from lens epithelium cells. biconvex body Lens nlens capsule –is generated by the cells of the subcapsular epithelium nsubcapsular epithelium –anterior and lateral parts→stayes –posterior part→lens fibers nlens fibres –very long (up to 12 mm), hexagonal cells, form the body of the lens –lens fibres are nucleated in the soft, outer cortex of the lens –lens fibres located deeper loose their nuclei and become part of the harder nucleus of the lens len20he Fasciculus opticus – optic nerve nis surrounded by the three meninges nc.t. septa, which arise from the pia mater, separate the fibre bundles in the optic nerve nthe axons in the optic nerve are supported by astrocytes and oligodendrocytes, microglia is also present nervus opticus nervus opticus Eyelid HP_img6-19-8 cutaneous part conjunctival part Meibomian glands – tarsal /sebaceae/ Zeiss glands /gl. sebaceae ciliares/ Moll glands /gl. sudoriferae ciliares – apocrine/ tarsal plate Eyelid /palpebra oculi/ oko14 tarsal plate and tarsal Meibomian glands /sebaceae/ Conjunctiva HP_img6-19-8a stratified columnar epithelium with goblet cells lamina propria mucosae Lacrimal apparatus nlacrimal gland –compound tubuloalveolar gland producing a lysosyme-rich serous fluid nlacrimal canaliculi –superior –inferior –lenghth: 8 mm, lined with s.s.epi nlacrimal sac nnasolacrimal duct –opens into the meatus inferior –lined with a pseudostratified ciliated epi tears Lacrimal gland Image_000175A tears Eye – list of slides n88. Anterior eye segment n89. Posterior eye segment n90. Fasciculus opticus n91. Palpebra n92. Glandula lacrimalis retina- animace