Monday, December 13, 2010

Optic Radiation

The Optic radiation is a thick bundle of axons which lie in a fanlike pattern, going from relay neurons in the lateral geniculate body of the thalamus to the visual cortex along the calcarine fissure. Carrying visual information to the occipital lobe, the optic radiation fibers are found in each cerebral hemisphere.

Both optic radiations split into two parts on each side and travel in the following way: 1) fibers from the inferior retina, which is also called "Meyer's loop", must pass through the temporal lobe by looping around the inferior horn of the lateral ventricle, carrying information from the superior part of the visual field; 2) fibers from the superior retina, also called "Baum's loop", travel straight back through the parietal lobe to the occipital lobe in the retrolenticular limb of the internal capsule to the visual cortex, carrying information from the inferior part of the visual field.