PHGY 210 Lecture Notes - Occipital Lobe, Fiber Bundle, Superior Colliculus
Document Summary
The neural pathway leaving the eyes starting with the optic nerve. The optic nerve, optic chiasm, and optic tract. The ganglion cell axons leaving the retina pass through three structures before forming synapses in the brain stem (see fig. 10. 2): optic nerve, optic chiasm, optic tract. The optic nerves exit the left and right eyes at the optic disks and combine to form the optic chiasm. Here the axons originating in the nasal retinas cross from one side to the other and this is called decussation (i. e. the crossing of a fiber bundle from one side of the brain to the other). In this case the decussation is partial and following this crossing, the axons of the retinofugal projections form the optic tracts. Left visual hemifield: objects appearing to the left of the midline. Right visual hemifield: objects appearing to the right of the midline (see fig.