Visual System Flashcards
Retina
Contains the visual receptors
Covers 2/3 of eye
Layers of cells
Fovea
Centre of visual field
Has high concentration of receptors
Light in environment travels as…
Electromagnetic energy
Light waves pass through…
Cornea
What focuses waves onto the retina?
Cornea and lens
Pupil
Opening into inner chamber
Controls amount of light entering eye
Axons which eventually form optic nerve travel across X before leaving eye via Y
Retinal surface
Retinal blind spot
2 types of visual receptors
Rods and cones
Rods
Vision in dim light
Cones
High acuity
Concentrated in fovea
Daytime color
These transduce electromagnetic energy into action potential
Rods and cones
Optic chiasma
Where optic nerves from 2 eyes meet
Reorganization of fibers occurs here
From optic chiasma, optic tract runs to part of thalamus (X), continues to Y, then Z
LGN - lateral geniculate nucleus
Optic radiation
Cortex of occipital Iobe
Visual cortex is organized functionally into…
Columns of neurons
Orientation column
Reds versus blues and violets regarding wavelength
Reds have longer wavelength
