Mot<)r nishirbditccs. 



429 



muscles the cfifccts of the spasms arc of little importance, except 

 that in kmg; standin^^ contracture atrophy is likely to develop. 

 Spasm of the respiratory muscles of necessity causes fatal suffo- 

 cation because of interference willi respiratory movements. 

 Spasms of the muscles of mastication cause starvation. In other 

 examples a fatal termination may be explained by the primary or 

 some collateral action exerted by the poisons causing' the con- 

 vulsions, the tetanus poison for example acting both by the 

 lesions induced in the ganglionic cells and by a hemolytic action. 

 It should be kept in mind that th.e spasms themselves are noth- 

 ing more than the symptoms of the actual nervous disturbances. 



(For details v. Friedberger-Fr(")lincr, Lchrbucli tier klinischcn fJiilcr- 

 siichifiii^siiicfliodcii f. Ticrarztc. III. Aufl. Stuttgart. F. Enke.) 



Loss of muscular power is termed [^als\ (akiiicsis [a. prii'.,] 

 TyKij/T/o-is, nv)vement ) and may be differentiated into a complete loss of 

 mobility (paralysis) , or ])artial loss {paresis) in which the power 

 of the muscles to perform movements is only reduced in degree. 

 In case of deficiency in co-ordination, where the movements are 

 performed clumsily and hesitatingly, the term ataxia ( a priv., 

 ij Td^ts, arrangement ) is employed. Loss of motion occurs in 

 pathological changes which directly inhibit muscular contractility 

 (atrophy, inflanuuation, rupture, degenerations), or interfere with 

 the movements of the bones (ankylosis of joints), or in conditions 

 of inefificient innervation which induce palsy both indirectly by 

 reducing the stimulus for contraction and by causing local 

 changes [in the muscle]. 



A faulty innervation itself is usuall}' the result of anatomical 

 changes involving the ganglionic cells or nerve fibres and thus 

 interfering with the formation of impulses or interrupting their 

 transmission, as for example stretching^, disintegration of the 

 nervous substance by pressure (tumors), or destruction and degen- 

 eration from poisons (toxines, lead), or disturbances of blood sup- 

 ply. The location of the changes may be in the central motor, 

 apparatus, cerebral cortex or cord (cerebral or spinal palsy), or 

 in the nerve trunks and their terminations (peripheral palsy). 



The central and some of the peripheral palsies are usually 

 unilateral (hemiplegia) because they are 'usually due to focal 

 lesions, to local changes, in one of the bilaterally i^laced nerve 

 ganglia or nerves; wdiile spinal palsies generally involve both 

 sides of tlie body (paraplegia) because in the comparatively small 

 transverse area of the spinal cord the lesion causing the anatomical 



