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Essay On Human Visual System

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Human sensory perception is facilitated by a number of extremely complex systems that are responsible for relaying sensory information to the brain. Two such systems are the visual system and the auditory system.
The human visual system can be broken down into three major components: the retina, the visual pathway, and the visual cortex.197 Each of these three components house complex systems within themselves comprised of many small, yet significant, parts that work together to allow the processing of visual information.
In order to understand visual processing, one must begin with the retina. The retina is a layered network of cells whose nuclei are grouped into three different sections. The first of these is the outer nuclear layer, …show more content…

The auditory nerve, much like the optic nerve of the visual system is composed of ganglion cell fibers. In the case of the auditory system, these fibers originate from ganglion cells in the spiral of the cochlea.112 The fibers of the auditory nerve carry signals to the brainstem where they then synapse with neurons within the cochlear nucleus. Information from the left ear is transmitted to the left cochlear nucleus and information from the right ear to the right nucleus, however, much like in the visual system, many of the fibers that leave the cochlear nucleus cross over to deliver signals to the contralateral side of the brain.112
The area of the brainstem that is believed to process information about where sounds are coming from, the superior olive to be exact, receives input from fibers on both sides of the nucleus.112 The auditory system differs from the visual system in that in the auditory system, the cochlea is unable to produce an exact placement of the location of a stimulus, whereas the retina, within the visual system, can directly identify where a stimulus originates.114 This, again, is where the superior olive comes into play computing very small time differences between the signals that arrive in each of the

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