The brain Flashcards
Describe the visual centre of the brain
The primary visual centre of the brain is located in the visual cortex in the occipital lobe of the brain. The visual cortex spans both hemispheres of the brain with the right hemisphere receving its input from the left hand side of the visual field while the visual cortex in the left side receives its input from the right side of the visual field. The visual cortex has several areas which each process different types of visual information such as colour shape or movement
How is the visual cortex involved in visual processing?
This process begins in the retina where light enters ans strikes the photoreceptors, then nerve impulses from the retina are transmitted to the brain via the optic nerve. Some nerve impulses from the retina travel to ceirtan areas of the brain involved in the coordination of circadian rhythms, but the majority terminate in the thalamus which acts as a relay station passing information on to the visual cortex
Describe the auditory centre of the brain
The auditory centre of the brain is concerned with hearing and most of this area lies within the temporal lobes on both sides of the brain where we find the auditory cortex. The auditory pathways begin in the cochlea in the inner ear where sound waves are converted into nerve impulses which travel via the auditory nerve to the auditory cortex in the brain. On the pathway from the cochela to the brain it stops at the brain stem where basic decoding takes place such as the duration and intensity of the sound, then it stops at the thalamus which acts as a relay station and carries out further processing of the auditory stimulus , then the last stop is the auditory cortex where it is recgonised and may result in an appropriate response
Describe the function of the motor cortex
This is responsible for the generation of voluntary motor movements, and this is located in the frontal lobe of the brain along a region called the precentral gyrus. Both hemispheres of the brain contain these, with the motor cortex on one side of the brain controlling the muscles on the other side of the body, the different parts of the motor cortex exert control over different parts of the body. These regions are arranged logically next to one another, foot control is next to leg control excetera
Describe the function of the somatosensory cortex
This detects sensory events arising from different regions of the body, and this is located in the parietal lobe of the brain along a region called the postcentral gyrus. The postcentral gyrus is the area of the cortex dedicated to the processing of sensory information related to touch. Using sensory information from the skin the somatosensroy crotext produces sensations of touch, pressure, pain and temperature which is then localised to specific body reigons, both hemispheres of the brainhave a somatosensory cortex with one side of the brain receiving information from the other side of the body
