Experimental researches applied to physiology and pathology / By e. Brown-Séquard.

  • Brown-Séquard, Charles-Edouard, 1817-1894.
Date:
1853
Catalogue details

Licence: Public Domain Mark

Credit: Experimental researches applied to physiology and pathology / By e. Brown-Séquard. 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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    after it has been cut in the neck, the vessels of the face and of the ear after a certain time begin to contract; their contraction increases slowly, but at last it is evident that they resume their normal condition, if they are not even smaller. Then the tem- perature and the sensibility diminish in the face and the ear, and they become in the palsied side the same as in the sound side. When the galvanic current ceases to act, the vessels begin to dilate again, and all the phenomena discovered by Dr. Bernard reappear. I conclude, that the only direct effect of the section of the cervical part of the sympathetic, is the paralysis and conse- quently the dilatation of the bloodvessels. Another evident con- clusion is, that the cervical sympathetic send motor nerve fibres to many of the bloodvessels of the head.* 8. Nearly all physiologists believe that the secretion of the gastric juice is stopped after the section of the two pneumo- gastric nerves. It is difficult to solve the question by experi- ments on warm-blooded animals, because they die too quickly after the section of the vagi. But it is not so with frogs. I have found that they are able to live perfectly well either after the extirpation of the medulla oblongata, or after the extirpation of the ganglia of the par vagum. In both these cases I have found that digestion continues to be performed. Consequently, if the gastric juice is necessary to digestion, it is certain that this liquid is secreted.f * My experiments prove, also, that the bloodvessels are contractile, and that the nerves are able to put them in action. I have also to remark that it is a fact, well established by Budge and Waller, that the cervical sympa- thetic is one of the motor nerves of the iris, and that the spinal cord is the origin of the nerve-fibres going from the sympathetic to the iris. Some experiments, which I intend to perform again, appear to prove that the same parts of the spinal cord which giye origin to some of the motor nerve- fibres of the iris, originate also the motor nerve-fibres going from the cer- vical sympathetic to the vessels of the head. Another conclusion is to be drawn from the results obtained by Budge, Waller, Bernard and myself; it is that the cervical sympathetic, instead of receiving its fibres from upwards to give them downwards, receives them downwards and distributes them upwards. fComptes rendus de l'Acad. des Sciences. Paris. 1847. T. xxiv. p. 363-64.