Nervous layer

    Cards (100)

    • nervous layer
      pigment layer and neural layer
    • retina is a layer of...
      thin transparent layer of nervous tissue
    • retina position - extends from...
      extends from optic disc to the ora serrata
    • surface area retina
      1,094mm2
    • thickest retina
      near optic disc
    • thinnest retina
      foveal floor and towards periphery
    • one degree of visual angle =
      288 μm on the retina
    • retina colour
      depends on amount of pigmentation of individual
    • small amounts of pigment retina
      -light coloured funds
      -allows for viewing sub-retinal elements
    • darkly pigmented retina
      -fundus = typically more heavily pigmented
      -sub-retinal elements not seen
    • retinal blood vessels - 2 types
      arterial supply and venous drainage
    • arterial supply retina
      central retinal artery and posterior ciliary artery
    • venous drainage retina
      arcade veins -> central retinal vein
      choroidal veins -> vortex veins
    • retinal zones
    • ora serrata - this is the transition zone between..
      transition zone between retina and pars plana
    • ora serrata postion
      underlying the vitreous base and associated with increased risk of retinal detachment
    • ora serrata width
      -2.1mm temporally
      -0.7mm nasally
    • optic disc - this is the region at back of eye where...
      region at the back of the eye where the optic nerve meets the retina
    • optic disc dimensions
      -vert diameter = 1.86mm
      -hor diameter = 1.75mm
      -3.4mm from macula
    • physiological cup - what type of area is it? what is it free from?
      -pale central area
      -free from nerve axons
      -cup disc ratio
    • area centralis - what type of zone and location
      circular zone of retina situated between the superior and inferior temporal arteries
    • area centralis shape
      elliptical
    • what is fovea
      clinical macula
    • macula lutea
      oval zone of yellow discolouration within centre of retina
    • macula lutea size
      3mm in diameter
    • yellow colour macula lutea dye name
      xanthophyll
    • fovea
      centre of area centralis
    • fovea position
      -4mm temporal to disc
      -0.8mm below horizontal meridian
      -1.85mm diameter thickness
    • what does fovea correspond to =
      5 degree of visual field
    • foveal avascular zone
      capillary free zone in centre of fovea
    • foveal avascular zone size
      0.2-0.6mm diameter
    • foveola
      -highest visual acuity
      -thinnest part of retina
      -devoid of ganglion cells
      -only cones and muller cells
    • umbo
      -tiny depression in the centre of foveola
      -corresponds foveol reflex
    • foveol reflex
      -intensely bright spot of light
      -visible due to reflexion of light from wall of foveal depression
    • loss of foveal reflex
      early sign of damage
    • neuron III
      conductive elements
    • neuron II
      conductive and associative elements
    • neuron I
      perception elements
    • retinal pigment epithelium - single layer of... contains....
      -single layer of hexagonal cells
      -contain melanin & lipofuscin
    • adjacent RPE cells have what type of junctions?
      tight junctions and constitute outer blood retinal barrier
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