Optical nerve

The optical nerve ( nervus opticus ) is the 2nd pair of the cranial nerves; it is the sensory Nerf sight, which transmits the visual information of the Rétine to the Cerveau.

Anatomy

The optical nerve is the 2nd pair of the 12 cranial nerves. It is a centripetal nerve like I. It thus goes from the periphery (the eye) in the center (side geniculate bodies). The optical nerve takes birth with the back of the retina by a nervous fiber cluster coming from the various cones and sticks. The nerve will traverse the muscular cone (formed by the muscles right sup, right inf, right ext., small oblique, large oblique and the raising device of the eyelid) making an S (what makes it possible to leave a room for maneuver to the nerve at the time of the movements of the brain in the brain-pan). It is accompanied by the oftalmic artery which comes to be rolled up around him. II will emerge in cranium by the optical channel (hole to dig in the small wing of the sphénoide) while passing before by one of the rings of Zinn. The two counterparts will meet on the level of the roof of the pituitary gland to form the optical chiasma which is in front of the pituitary stem. From this chiasma are born the two terminal sections from the nerve which will walk on towards the side geniculate bodies from where will leave optical radiations towards the visual cortex.

Physiology

The blind spot off the eye is produced by the absence off retina where the optic nerve leaves the eye. This is because there are No Photoreceptor S in this area. -->

Role in the diseases

  1. optical Neuropathy
  2. Syndrome of Traquair

ref.: vulgaris medical The pathology of the optical nerve gathers the affections called optical neuropathies. They are ignitions of this nerve, secondaries with problems tumoral (due to a tumor), vascular, toxic or degenerative. The syndrome of Traquair is a disease of the optical chiasma (meeting of the 2 optical nerves) associating:

  • a scotome (gap in the field of vision, due to nonperception in a territory of the retina) located side of the lesion

  • a temporal notch on other side, translating a lesion of the part before optical chiasma

External bond

  • The optic nerve one medical MRI
  • vulgaris

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