The diagnosis of diseases of the spinal cord / by W. R. Gowers.

  • Gowers, Sir William Richard, 1845-1915.
Date:
1884
Catalogue details

Licence: Public Domain Mark

Credit: The diagnosis of diseases of the spinal cord / by W. R. Gowers. Source: Wellcome Collection.

Provider: This material has been provided by The University of Leeds Library. The original may be consulted at The University of Leeds Library.

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    slight vibration tkrougli the muscle (which may be felt by the liand applied to the calf), which excites a contraction in the state of extreme irritability. This extreme irritability, however, has also to be explained. It is clearly the result of the passive tension placed upon the muscle, and it is, perhaps, a true reflex phenomenon, the afferent impidse being the tension on the muscular , fibres. It is thus assumed that the passive tension may produce two effects:—(1.) To cause, by reflex action, an excessive irritability to local stimuli—a state of incipient contraction in which an actual contraction is developed with extreme readiness. If the tension is gradual and gentle, the effect may be confined to this. (2.) If sudden, the tension excites not only the reflex irrita- bility, but also a local contraction. When this contraction is over, the continued tension on the relaxing fibres developes another contraction, and so on in the recurring clonus.* Additional evidence that the afferent impulse originates in the muscle, and not, as has been supposed, in the tendon, is fm-nished by the fact (which you may easily verify on yourselves) that the passive flexion of the foot causes a sensation of distinct pain in the muscle, and no sensation in the tendon—the pain proving that an afferent impulse does originate in the muscle tmder the conditions. The same conclusion is indicated by the fact that, while a lateral tap on the tendon will caiise the contraction, if the other edge of the tendon is so supported that the tendon cannot move under the tap, and so cannot affect the muscle, no contraction occurs. If it should be ultimately proved that the short interval which I have found to intervene between the tap and the contraction is suSicient for such a reflex process, each contraction may be reflex, but it will remain true that the impulse exciting it is from the muscle, and has little or nothing to do with the tendon, and that the term tendon reflex is an inaccurate and misleading term. It * In this comiection, it is interesting to note that physiologists have ascertained that a moderate resistance, or load, increases the contraction ■which results on a given stimulation through the nerve. (See Foster's rhysiology, 3rd Ed., p. 81.)