What are the eye nerves?
eye nerves are all cells in the retina, optical, oculomotor, trochlear and abduction nerves. These are also known as cranial nerves II, III, IV and VI. The retina contains many types of specialized neurons, including photo panels and retinal ganglium cells. Along with the optical nerve they are the foundation of a vision. The other three eye nerves control the muscles that move the eyeball.
The retina is an extension of the central nervous system sensitive system, on which light is projected by the eye lens. Photoreceptor cells of retina, bars and cones are specially adapted nerves that change chemically when the light hits them. Native cells react to the differences in brightness and are most active in the dark, while conical cells are sensitive to the colors of information that come from wavelengths of light. Other retina neurons are code of information that are electrically transmitted by gangli cells at the back of the retina. These neurons become an optical nerve after leaving the eye.
eye nerves develop from different tissues during pregnancy. The optical nerve comes from the same part of the embryo as most of the brain, including the front brain and thalamus. For this reason, it is classified as part of the central nervous system. Ganglion cells of retina and optical nerve make more than information transfer: actively sort them. Like neurons in the brain, they involve and process data, in this case they categorize color signals coming from cone cells and divide them into several groups called channels of color opponence.
About 1 million neurons of optical nerve runs from the brain to the ganglium cells of the retina. Half of the nerve fibers from each retina pass to the other side of the optical chiasm, which is located near the pituitary gland along the domozek path. From there the fibers are called an optical tract and passes the Thalam before reaching the visual bark of the parietal lobe where the light information is processedfrom the retina. Eye nerves end in various visual cortics.
Eye movement is controlled by cranial nerves III, IV and VI. The first, Oculomotoric Nerve, controls the lid, narrowing of pupils and a large part of the eye. The trochlear nerve is smaller and controls only one muscles of the eye, the superior oblique, which allows rolling and crossing the eyes. It is particularly susceptible to the trauma of the skull because of its long passage of the brain and fragility. The Abducens nerve only controls the ipsilateral side rectus muscles, which changes the eyeball directly to the side.