The Anatomy, Physiology and Histology of Optic Nerve

The optic nerve (Nervus opticus) is the second of the 12 cranial nerves and is considered to be a part of the central nervous system. It carries visual information from the neurosensory retina to the occipital cortex. The nerve consists of the axons of retinal ganglion cells (RGCs). These axons extend in an organized pattern from the RGC soma to the lateral geniculate nucleus where the neurons synapse. The nerve is subdivided into fascicles by connective tissue and glial septa, and it is surrounded by cerebrospinal fluid. The optic nerve has intraocular, intraorbital, intracanalicular, and intracranial parts and a length of approximately 50 mm. The central retinal artery, the Zinn-Haller circle formed by the short posterior ciliary artery extensions, and pial vessels take part in the blood supply of the nerve.