Lab 4 (ƒ3) - The Ventricles and Blood Supply

Cranial Nerves of the Telencephalon and Diencephalon

A. Cranial Nerve I

Cranial Nerves of the Telencephalon and Diencephalon

Before proceeding with the next segment of this exercise, be certain to locate and identify the olfactory bulbs and the olfactory tracts. They are located on the inferior surface of the frontal lobe and are associated with the olfactory nerve or cranial nerve I. Just rostral to the anterior perforated substance the olfactory tract divides into the medial olfactory stria and the lateral olfactory stria (see inset). The lateral olfactory stria terminates in the uncus and structures forming the limbic system.

B. Cranial Nerve II

Notice also the optic nerve, cranial nerve II, the optic chiasm and the optic tract. Normally the optic nerve is attached to the eye. The optic chiasm is formed by the decussation (midline crossing) of optic nerve fibers that innervate the nasal half of the eye. The optic tract consists of the uncrossed optic nerve fibers from the temporal half of the ipsilateral eye and the crossed optic nerve fibers from the nasal half of the contralateral eye. The optic tract travels laterally and terminates in the thalamus of the diencephalon.