Question

At the optic chiasm, which of the following is true?

1) Axons from the lateral halves of each retina cross.
2) Axons from the retinae synapse on those from the other half.
3) The olfactory nerve crosses to the opposite side of the brain.
4) Axons from the medial halves of each retina cross.
5) The optic nerve enters the cerebellum.

Answer 1

At the optic chiasm, it is true that axons from the medial halves of each retina cross to the opposite side of the brain.

Step-by-step explanation:

At the optic chiasm, axons from the medial halves of each retina cross over to the opposite side of the brain. This decussation allows the right field of view of each eye to be processed on the left side of the brain and the left field of view to be processed on the right side.

The axons from the medial retina of the left eye, for instance, will cross to the right hemisphere of the brain at the optic chiasm. Conversely, the axons from the lateral halves of each retina do not cross at the optic chiasm and remain on the same side as their originating eye. Therefore, the correct statement is that axons from the medial halves of each retina cross at the optic chiasm, which is option 4.