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Unformatted text preview: 2-18-08 anatomy notes1.Organ Systems2.Nervous Systema.Vision (sight)i.Physiology of Vision1.Requirementsa.Image focused on the retinai.If that process is impaired, vision is impairedb.Rods & cones reaction to light raysi.Their reaction is to initiate nerve impulses or APsc.Transmission of APsi.Over optic nerve to occipital lobed.Visual interpretation centeri.Primary visual cortex2.Image focusing-lens focuses image on the retinaa.Far Vision-object more than 20 feet away and light rays are paralleli.Ciliary Muscles-relaxed, resting positionii.Choroid Coat-resting positioniii.Tension on suspensary ligament-suspensary ligament exerts tension on the lens1.Tension all around the edge2.Lens has low curvature (flat)b.Near Vision-object less than 20 feet away & light rays are divergent from point sourcei.Ciliary Muscles contractii.Choroid pulled forward towards the corneaiii.Decreased tension on suspensary ligament b/c of choroid being pulled forward1.Less tension on lens (lens is elastic)...
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