A contribution to the study of muscular tremor / by Frederick Peterson.

  • Peterson, Frederick, 1859-1938.
Date:
[1888]
Catalogue details

Licence: Public Domain Mark

Credit: A contribution to the study of muscular tremor / by Frederick Peterson. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

    2/14 (page 2)
    The so-called fibrillar contractions3 occur in the muscles of the tongue after section of the hypoglossal nerve (Schiflf), and in the muscles of the face after section of the facial nerve. According to Bleuler and Lehmann these may take place for six months in the tongues of rabbits after section of the hypoglossal. Some drugs cause such fibrillar contractions, as aconitin, guanidin, pilocarpin and physostigmin, accord- ing to Brunton by irritating the motor nerve-endings, for the contractions are gradually abolished by curara. Such phenomena may be termed idio-muscular. Yet the re- searches of Gerlach tend to obscure the doctrine of specific muscular irritability by showing that a nerve fibre on pene- trating the sarcolemma divides into inter-fibrillar threads, which come into direct relation with the sarcous substance. Now as regards the physiological action of muscle through the mediation of the nervous system, we learn that a con- tinued voluntary contraction in man consists of a series of single contractions rapidly following each other, frequent intermittent vibrations which reach their maximum when a person shivers (E. Weber). Tetanus is a condition of continuous vibratory contrac- tion, an accumulation of contractions which follow each other too rapidly for relaxation to take place. Horsley and Schafer4 have demonstrated that such con- tractions, whether natural or not, are caused by impulses from the central nervous system along the motor nerves, discharged rhythmically at the rate often per second. This innervation rhythm may be generated in the motor cells of the spinal cord, in the medulla, pons or mesencephalon, while the cortical cells may produce rhythmic impulses numbering twelve or thirteen per second. J. von Kries, in a study of volitional muscular activity,5 calls attention to familiar voluntary rhythmical movements, and the. number that can be made per second. For instance, in the repetition of la-la-la the muscles engaged in articula- tion and moving the jaw cannot be made to exceed in fre- 3 Ibid., p. 512. •< Journal of Physiology, i885, pages 96 and in. » Archivfur Physiologie, 188b.