Visual Pathway Flashcards
What is the nasal field of vision?
Half of the vision which is closest to the eye and travels contralaterally down the optic chiasm to the lateral geniculate nucleus to the visual cortex.
What is the temporal field of vision?
Half of the vision furthest from the eye and travels ipsilateral at the optic chiasm to the lateral geniculate nucleus and visual cortex.
What is the optic radiation?
Projection tract from the lateral geniculate nucleus to the visual cortex.
What is the order of the visual pathway?
Optic nerve
Optic chiasm
Lateral geniculate nucleus
Optic radiation
Visual cortex
Why does Homonymous hemaniopia occur?
Damage to the visual pathway after the optic chiasm, affecting the ipsilateral nasal field and the contralteral temporal field of vision.
What is the consequence of optic nerve lesion?
Loss of vision to the eye affected.
What is the consequence of optic chiasm lesion?
Affects the crossing over of the nasal visual fields, causing bitemporal hemaniopia.
What is the consequence of a lesion to the optic tract?
Right Homonymous superior quadrantopia, where the field of vision on the superior portion of the ipsilateral nasal and contralateral temporal of both eyes are affected.
What is the role of the macula?
Responsible for central vision and fine detail.
Which part of the vision is unaffected by occlusion of the posterior cerebral artery?
Macula due to receiving alternative blood supply from the middle cerebral artery. This is macular sparing.
What is the upper optic radiation?
Carries fibres from the superior retinal quadrants to the visual cortex, via the parietal lobe.
What is the lower optic radiation?
Carries fibres from the inferior retinal quadrants to the visual cortex via the temporal lobe
