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Anatomia retina

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  • 1. INSTITUTO DE LA VISION07 marzo 2011Dr. Fily Martinez D.

2. RETINA: 3. Retina: develops as part of the brain1. (outer layer) Fibrous: dense connective tissue Sclera white of the eyeRememberthe 3 layers ofCorneathe external2. (middle layer) Vascular: uveaeye? Choroid posterior, pigmented Ciliary body Iris3. (inner layer) Sensory Retina and optic nerve Retina is 2 layers Outer thin pigmented layer: Melanocytes (prevent light scattering) Inner thicker neural layer Plays a direct role in vision Three type of neurons: 1. Photoreceptors 2. Bipolor cells 3. Ganglion cells3 4. Light passes through pupil in iris, through vitreous humor,through axons, ganglion cells and bipolar cells, tophotoreceptors next to pigmented layer4 5. Photoreceptor neurons signal bipolar cells, which signalganglion cells to generate (or not) action potentials: axons runon internal surface to optic nerve which runs to brain*Know that axons from the retina form the optic nerve, CN II 5 6. Photoreceptors: 2 types Rod cells More sensitive to light - vision permitted in dimlight but only gray and fuzzy Only black and white and not sharp Cone cells High acuity in bright light Color vision 3 sub-types: blue, red and green light cones*Know that rods are for B & W and cones are for color6 7. If you want moredetail, itsfascinating 7 8. Retina throughophthalmoscope Macula: at posterior pole Fovea: maximal visual acuity (most concentrated cones) Optic disc: optic nerve exits Vessels 8 9. Green is area seen by both eyes, and isthe area of stereoscopic vision Visual pathwaysAt optic chiasm, medial fibers from each eye(which view lateral fields of vision) cross toopposite side. Optic tracts (of crossed anduncrossed, sensing opposite side of visual field ofboth eyes) synapse with neurons in lateralgeniculate of thalamus. These axons form the opticradiation and terminate in the primary visual cortexin the occipital lobe. Left half of visual fieldperceived by right cerebral cortex, and vice versa.9 10. TIPOS CELULARES: CEL. FOTORRECEPTORAS: CONOS Y BASTONES. CEL. HORIZONTALES. CEL. BIPOLARES. CEL. AMACRINAS. CEL. INTERPLEXIFORMES. CEL. GANGLIONARES. 11. CAPAS DE LA RETINA:1.EPR: CELULAS PIGMENTADAS.2.CAPA DE FOTORRECEPTORES: CONOS Y BASTONES.3.MLE: UNION INTERCEL. ENTRE CEL. FR Y CEL. DE MLLER.4.CAPA NUC. EXT: FORMADA POR LOS NUCLEOS CELULARES DELAS CEL. FOTORRECEPTORAS.5.CAPA PLEXIFORME EXT: CONEXIN SINAPTICA DE CEL. FR, BIPY HORIZ.6.CAPA NUC. INTER: FORMADA POR NUC. DE LAS CEL.BIP, HORIZ. Y AMACRINAS.7.CAPA PLEX. INTER: CONEXIN SINAPTICA ENTRE CEL.BIP, AMACRINAS Y GANGLIONARES.8.CAPA DE CEL. GANGLIONARES.9.CAPA DE FIBRAS NERVIOSAS.10. MLI: LAMINA BASAL QUE SEPARA LAS CEL. DE MLLER. 12. RETINA: EPRES UNA MONOCAPA DE CELULAS QUECONTIENEN MELANOSOMAS.TEJIDO VITAL PARA ELMANTENIMIENTO DE LA FUNCIONFOTORRECEPTORA.UNO DE LOS TEJIDOS CON MAYORACTIVIDAD METABOLICA. 13. FUNCIONES DEL EPR:REGULACION DE LA TEMPERATURAMANTENIMIENTO DE LA BARRERAHEMATORRETINIANA EXTERNAADHESION RETINIANAABSORCION DE LA LUZ 14. FUNCIONES DEL EPR: FAGOCITOSIS DE LOS SEGMENTOS DESPRENDIDOS DE LOS FOTORRECEPTORES APORTE DE O2 Y NUTRIENTES A FOTORRECEPTORES TRANSP. ACTIVO DE MAT. DENTRO Y FUERA 15. RETINA: ELEMENTOS VASCULARES CIRCULACION COROIDEA RETINA EXT. ART. RETINIANA CENTRAL RETINA INT. CIRCULAC. MACULAR ART. CILIORETINAL VASOS SANGUINEOS RETINIANOS MANTIEN LABARRERA HEMATORRETINIANA INTERNA 16. Thank you. RetinaService.

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