Optic nerve function & Structure
The optic nerve is located in the back of the eye. It is also called the second cranial nerve. This is the second of several cranial nerve pairs. The task of the optic nerve is to transmit visual information from the retina to the brain’s viewing centers by means of electrical impulses.
Optic nerve function
The optic nerve function consists of ganglion cells or nerve cells. It consists of over one million nerve fibers. Our dead point is caused by the lack of specialized photosensitive cells or photoreceptors in the part of the retina in which the optic nerve leaves the eye.
Glaucoma is one of the most common diseases affecting the optic nerve. Glaucoma cause from high intraocular pressure or high pressure in the fluid inside the eye (glassy fluid). This high pressure compresses the optic nerve and causes cell death. This is known as atrophy of the optic nerve.
Although the optic nerve is part of the eye, it considers being part of the central nervous system.
Structure of optic nerve classifies as the second of the twelve paired cranial nerves. It is technically part of the central nervous system, not of the peripheral nervous system, because it comes from the outflow of the diencephalon (optic stalks) during embryonic development.
As a consequence, optic nerve fibers coated with myelin produce from dendrocytes and not by Schwann cells in the peripheral nervous system and are encapsulated in the meninges of the brain. Peripheral neuropathies, such as Guillain-Barré syndrome, do not affect the optic nerve. However, most often the optic nerve group with other eleven cranial nerves and considered part of the peripheral nervous system.
The optic nerve rather covers in all three layers of the tire (tire, arachnoid, and tire) than epineurium, perineurium, and endoneurium occurring in the peripheral nerves.
The fibrous pathways of the central nervous system of mammals (in contrast to the peripheral nervous system) are incapable of regeneration, and thus damage to the optic nerve causes irreversible blindness. Retinal fibers run along the optic nerve to the nine primary visual nuclei in the brain from which the main transmitter enters the original visual cortex.
A photo of the fundus showing the back of the retina. The white circle is the beginning of the optic nerve.
It consists of axons of retinal ganglion cells and glial cells. Each human optic nerve contains from 770,000 to 1.7 million nerve fibers, which are the axons of retinal ganglion motile cells. In a well that has high stringency, because ganglion cells connect to only 5 photoreceptor cells; in other areas of the retina, they connect with many thousands of photoreceptors.
Others Optic nerve function
Optic nerve leaves the orbit through the visual channel. It is running on the medial side towards the visual muzzle. The partial decomposition of the fibers from the temporal visual fields (nasopharyngeal) of both eyes occurs. The proportion of splitting fibers varies depending on the species and correlate with the binocular grade that the species enjoy.
Most of the optic nerve axons end up in the lateral nucleus. It information pass to the visual cortex, while other axons end up in the pre-temporal nucleus and take part in the reflex movements of the eyes.
Other axons end in the supra chiasm nucleus and take part in the regulation of the sleep and wakefulness cycle. Its diameter increases from about 1.6 mm in the eye to 3.5 mm in the orbit up to 4.5 mm in the space of the skull.
The length of the optic nerve component is 1 mm on the globe. It is 24 mm on the orbit, 9 mm on the visual canal and 16 mm in the space of the skull before attachment to the visual band. There is a partial decomposition, and about 53% of the fibers intersect to form optical lines. Most of these fibers end in the lateral elbow body.