Nervous and mental diseases . he muscle is more readily caused to contract by the constantcurrent, but that the normal mastering strength of the negativeclosing contraction over the positive has disappeared and that thepositive closing contraction is equal to or greater than the thus : A. C. C. = or > C. C. C. Anodal tetanus (A. T.)is often obtained. This polar difference continues until the ner^-eeither regenerates and regains its normal status, or, failing to recover,gradually the galvanic irritability subsides. It is entirely abolishedwith all other electrical response
Nervous and mental diseases . he muscle is more readily caused to contract by the constantcurrent, but that the normal mastering strength of the negativeclosing contraction over the positive has disappeared and that thepositive closing contraction is equal to or greater than the thus : A. C. C. = or > C. C. C. Anodal tetanus (A. T.)is often obtained. This polar difference continues until the ner^-eeither regenerates and regains its normal status, or, failing to recover,gradually the galvanic irritability subsides. It is entirely abolishedwith all other electrical responses in complete recovery take place, the restitution is marked ordinarily, first,by a return of voluntary control, then, by the appearance of galvanicand faradic excitability in the nerve, and, last of all, by faradic excita-bility of muscle. The hyperexcitability of the muscle to galvanism and M. tibial, antic. M. extens. digit, M. peroneus brevis M, extensor hallucislong. Mi. interossei dorsales. iVeri. peroneus M. gastrocneni. peroneuslongus M. soleus M. flexor hallucis long. M. extens. digit, M. abductor digiti min. Fig. 13.—Nerves and motor points iu lower extremity. the polar variations from the normal gradually right themselves at thesame time. These changes and the pathological process in nerve andmuscle are shown in the diagrams (Fig. 14) modified from Erb. In some cases we find a partial reaction of degeneration^ the nerve- 48 NERVOUS AND MENTAL DISEASES. trunk response being only slightly modified. The inverted polar formulais not necessarily present. The most essential element in the reactionof degeneration is the modal change,—the slowly appearing muscularresponse,—so at variance with the instantaneous eifect produced in in importance is the lessened faradic control of the muscle, and, last,the polar modifications. The variations in the galvanic and faradicresponses in disease are due principally
Size: 1049px × 2382px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, booksubjectmentalillness, booksubjectnervoussys
