Visual defect is contralateral homonymous hemianopia with macular sparing. What is the cause for it
Block in posterior cerebral aery supplying occipital lobe - Contralateral homonymous hemianopia with macular sparing Block in optic tract -Contralateral homonymous hemianopia CHOICE EXPLANATION & ELIMINATION REASON 1 Not correct 2 Not correct 3 Not Correct statement 4 Correct statement Visual pathways. Transection of the pathways at the locations indicated by the letters causes the visual field defects shown in the diagrams on the right. The fibers form the nasal half of each retina decussate in the optic chiasm, so that the fibers in the optic tracts are those from the temporal half of one retina and the nasal half of the other. A lesion that interrupts one optic nerve causes blindness in the eye (A) A lesion in one optic tract causes blindness in half of the visual field. (C) and is called homonymous (same side of the both visual fields) hemianopia (half-blindness). Lesions affecting the optic chiasm destroy fibers form both nasal hemiretinas and produce a heteronymous (opposite sides of the visual fields) hemianopia (B) Occipital lesions may spare the fibers from the macula (as in D) because of he separation in the brain of these fibers from the others subserving vision.
Block in optic tract
Block in optic nerve
Block in optic chiasma
Block in posterior cerebral aery supplying visual coex
Neuroanatomy 1