. Diseases of the nervous system . the mus-cle areas affected by disease of the second neuron are induced, and these areattributed to the absence of control, therefore the inhibition, of impulses ofthe will, and to the preponderance of reflex irritation. Often, however, theparalysis is complete. The second motor neuron originates in those portions of the cortex ofthe brain which we designate as the motor. From animal experiments (Ewaldand Hitzig, H. Munk) as well as by embryologic investigation and clinical NEURON SYSTEMS AND NEURON DISEASES 61 research combined with the findings at autopsies,
. Diseases of the nervous system . the mus-cle areas affected by disease of the second neuron are induced, and these areattributed to the absence of control, therefore the inhibition, of impulses ofthe will, and to the preponderance of reflex irritation. Often, however, theparalysis is complete. The second motor neuron originates in those portions of the cortex ofthe brain which we designate as the motor. From animal experiments (Ewaldand Hitzig, H. Munk) as well as by embryologic investigation and clinical NEURON SYSTEMS AND NEURON DISEASES 61 research combined with the findings at autopsies, we know that the motorcerebral cortex is situated in the posterior and lower portion of the frontallobe, and in the anterior portion of the parietal lobe, especially in the anteriorand posterior ( ?) central convolutions. Here also there are isolated fields for certain motor regions. Thus, the center for the lower extremities is situated in the central con-volutions on both sides of the upper portion of the central furrow ( Fig. 55.—Convexity of the Brain from Above. (After Toldt.) 55-57); those for the upper extremity in the lower portion; for the facialand hypoglossal nerves the center is quite low down; that for the larynx isin the operculum; the center for movements of the trunk is in front of thecenters for the extremities in the posterior part of the two upper frontal con-volutions; that for speech beside the center for the larynx in the posteriorlower frontal convolution close to the operculum. The center for the move-
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectnervoussystem, bookye
