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21 Cards in this Set
- Front
- Back
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Optic Disc |
extrance/exit for neurovasculature. no photoreceptors |
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Macula |
Highest concentration of photoreceptors. Most are cones. |
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Fovea Centralis |
Highest concentration of photoreceptors within the Macula. (Center of Macula) |
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Horizontal cells |
help improve distinctness of lines - processing within the eye. |
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Rods |
- High sensitivity, specialized for night vision - More photopigment so captures more light - Low acuity - achromatic - extra-macular areas - peripheral vision |
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Cones |
- Lower sensitivity, specialized for day vision - High acuity - Chromatic - 3 types of cones, each sensitive to different parts of the visible spectrum - concentrated in macular region |
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Binocular zone |
- Area of visual field that both eyes see. - measured in degrees - gives us depth perception |
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Nasal hemiretina |
Info from here decussates. |
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Temporal hemiretina |
Info from here does not decussate |
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superior visual field |
picked up by inferior retina |
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inferior visual field |
picked up by superior retina |
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Projections from the Visual Field |
90% to Lateral Geniculate Nucleus of the Thalamus 10% to other areas: - pretectal area of midbrain - Hypothalamus - Superior colliculus of the midbrain |
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Projections to Pretectal area of the midbrain |
input used to produce pupillary constriction reflexes 2* neurons --> pretectal Pretectal --bilateral--> Edinger-Westphal nuc. E-W nuc --> parasymp. pahtway |
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Projections to Hypothalamus |
pupillary dilation reflex provides light-cycle information: circadian rhythms, reproductive cycles |
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Projections to Superior Colliculus of Midbrain |
- input used to generate saccadic eye movements - coordinates visual, somatic and auditory info. - convergence accommodation reflex (cross eyes to see object moving closer) - Corneal blink reflex |
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Lateral Geniculate Nucleus of the Thalamus |
Processes visual information that is sent to the cortex and results in visual perception. LGN has layers to help maintain retinotopic organization of information. |
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Genticulocalcarine Fibers Parietal Loop |
- visual info from inferior visual field (superior retina) - goes to superior bank of calcarine fissure |
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Genticulocalcarine Fibers Temporal loop (Meyer's loop) |
- visual info from superior visual field (inferior retina) - goes to inferior bank of calcarine fissure |
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Occipital Lobe Input |
Primary visual cortex: raw data Secondary visual cortex: ant., sup., and inf. to primary. Provides analysis and visual meaning. |
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Occipital Output: Ventral Stream |
occipital lobe --> temporal lobe
helps identify objects |
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Occipital Output: Dorsal Stream |
occipital lobe --> parietal lobe analysis of motion and positional relationships |
