The point where optic nerves from each eye cross over to the opposite half of the brain is the optic
a. chiasm
b. disk
c. retina
d. cornea

If you can understand the lower figure on this page, then you have learned the major pathway that visual information takes on its way from the eye to the primary visual cortex. The figure is really not too difficult to understandreally. Imagine that the colored bar (half red, half blue) is in front of your eyes. The red part of the bar will project to the nasal part of your left retina and the temporal (lateral) part of your right retina. The blue part of the bar will project to the nasal part of your right retina and the temportal (lateral) part of your left retina. Right and left visual information cross to opposite sides of the brain. This crossover occurs in the optic chiasm. After the optic chiasm, information about the right visual field (blue) is on the left side of the brain, and information about the left visual field (red) is on the right side. The pathways stay this way all the way up to the visual cortex. Follow the blue and red lines from the eyes to see the flow of information. From the retina, the first synapse is in the lateral geniculate nucleus of the thalamus. The next synapse is made in primary visual cortex in the occiptal lobe.

Electoral current force mechanical advantage if the wheel and axle is 2 n and the output force is 20 n