where does the optic nerve cross the midline ​
optic chiasm
title: Optic nerve text: Optic nerve The optic nerve, also known as cranial nerve II, or simply as CN II, is a paired nerve that transmits visual information from the retina to the brain. In humans, the optic nerve is derived from optic stalks during the seventh week of development and is composed of retinal ganglion cell axons and glial cells; it extends from the optic disc to the optic chiasma and continues as the optic tract to the lateral geniculate nucleus, pretectal nuclei, and superior colliculus. The optic nerve is the second of twelve paired cranial nerves and is technically part of the title: Optic nerve text: of the optic nerve terminate in the lateral geniculate nucleus from where information is relayed to the visual cortex, while other axons terminate in the pretectal nucleus and are involved in reflexive eye movements. Other axons terminate in the suprachiasmatic nucleus and are involved in regulating the sleep-wake cycle. Its diameter increases from about 1.6 mm within the eye to 3.5 mm in the orbit to 4.5 mm within the cranial space. The optic nerve component lengths are 1 mm in the globe, 24 mm in the orbit, 9 mm in the optic canal, and 16 mm in the cranial title: Oculomotor nerve text: passes medially over the optic nerve. It supplies the superior rectus and levator palpebrae superioris. The "inferior branch" of the oculomotor nerve or the "inferior division", the larger, divides into three branches. All these branches enter the muscles on their ocular surfaces, with the exception of the nerve to the inferior oblique, which enters the muscle at its posterior border. The oculomotor nerve (CN III) arises from the anterior aspect of mesencephalon (midbrain). There are two nuclei for the oculomotor nerve: Sympathetic postganglionic fibres also join the nerve from the plexus on the internal carotid artery in the wall of title: Ophthalmic nerve text: form the external nasal branch. The ophthalmic nerve is joined by filaments from the cavernous plexus of the sympathetic, and communicates with the oculomotor, trochlear, and abducent nerves; it gives off a recurrent (meningeal) filament which passes between the layers of the tentorium. The ophthalmic nerve supplies branches to the cornea, ciliary body, and iris; to the lacrimal gland and conjunctiva; to the part of the mucous membrane of the nasal cavity; and to the skin of the eyelids, eyebrow, forehead and nose. It is the smallest of the three divisions of the trigeminal, and arises from the upper part title: Optic nerve text: (which is the part within the orbit). 3. intracanicular part (which is the part within a bony canal known as the optic canal); and, 4. cranial part (the part within the cranial cavity, which ends at the optic chiasm). From the lateral geniculate body, fibers of the optic radiation pass to the visual cortex in the occipital lobe of the brain. In more specific terms, fibers carrying information from the contralateral superior visual field traverse Meyer's loop to terminate in the lingual gyrus below the calcarine fissure in the occipital lobe, and fibers carrying information from the contralateral inferior visual