What structure is the arrow pointing to?
Incorrect. The optic nerves merge to form the indicated structure. Try again!
Incorrect. The lateral geniculate body is distal to this structure within the visual pathway. Try again!
Correct. The optic chiasm is where optic nerves come together and where the optic tracts start. The retinal ganglion axons coming from nasal retina (temporal visual field) cross to enter the contralateral optic tract; the retinal ganglion axons coming from temporal retina (nasal visual field) do not cross, entering the ipsilateral optic tract. Damage to chiasmal crossing fibers causes "bitemporal hemianopia." Common causes are pituitary tumors, meningiomas, aneurysms, and craniopharyngiomas.
Incorrect. The optic tracts emerge from the indicated structure. Try again!