The post central gyms, according la Brodman's mapping, consists of areas 3,2.1. Plasticity of the neurons Suppose the median nerve of the right hand i

are liable la alter slightly if the situation alters The post central gyms, according la Brodman's mapping, consists of areas 3,2.1. Plasticity of the neurons Suppose the median nerve of the right hand is destroyed and consequently there is sensory loss of The palm of the right hand. The corresponding area of the sensory homonculus. (SI), in the left hemisphere, is Thus, now, useless With passage of lime it will be noted that impulses from some neighbouring nerves (neighbours of the now destroyed median nerve], somehow, project [to some extent), on the palm aiea of the left SI, so thai this area now regains some activity. This is an example of plasticity of the neuronal activity Further projection and body imaging From the post central gyrus, further order neurons arise to end in parietal lobe, wtiere various informations are further integrated and body image made For a short account of body image (and parietal lobe neglect) see introduction to sec XB l and chap 6 sec XD, parietal lobe) Comparison between the lemniscal and the anterolaleral systems (1) The lenimscal system appeared late in the evolution and The anterotaleral system is more primitive. (2) The anterolaleral system conveys rather crude senses, whereas Ihe lernniscal system conveys rather finer senses. (3) Conduction through the lernniscal system is faster as the journey To The thalamus is accomplished by two neurons whereas the same is accomplished in the anTerolaleral system, very often, by more than two neurons