IV.B.1 Head: Nasal & Orbital Region Page 3 of 6

Optic Nerve CN II

	The optic nerve leaves the orbit through which foramen?
Optic canals of the sphenoid bone.
	The some of the optic nerve crosses at the optic chiasm. Which nerve fibers cross at the chiasm?
The nasal hemiretinal fibers cross and therefore the fibers seeing the same visual field end up on the same side of the brain.

The anterior part (from the orbit to the chiasm) of the nerve is called the optic nerve. The posterior part (from the chiasm to the visual cortex) of the nerve is called the optic tract.

Step 5:  Using the Draw tool, point out the left optic tract on the axial cut in the Cross-Sections window. The optic tracts wrap around the thalmus on their way to the visual cortex.