An experimental investigation into the functions of the eighth pair of nerves, or, The glosso-pharyngeal, pneumogastric, and spinal accessory / by John Reid.

  • Reid, John, 1776-1822
Date:
[1840?]
Catalogue details

Licence: Public Domain Mark

Credit: An experimental investigation into the functions of the eighth pair of nerves, or, The glosso-pharyngeal, pneumogastric, and spinal accessory / by John Reid. Source: Wellcome Collection.

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    after each pinch of the pharyngeal branch of the par vagum with the forceps ; while the same irritation applied to the glosso-pha¬ ryngeal immediately afterwards, was followed by no visible muscu¬ lar movement. Being now satisfied that in the preceding expe¬ riment we had in the second operation divided the pharyngeal branch of the par vagum instead of the glosso-pharyngeal, the ani¬ mal was killed, and the dissection proved that we were right in our conjecture. Exp. III.—-The nerve was exposed on one side in a small cocker dog affected with the distemper, but no satisfactory evidences of sensation or muscular movements were observed. This might arise from the sickly condition of the animal, or, as we shall im¬ mediately show, from the nerve being only irritated anterior to, or on the distal side of that part of the trunk where the pharyngeal branches leave it. Exp. IV.—The glosso-pharyngeal nerve was first exposed on one side, and then on the other, in a middle-sized terrier. Very forcible convulsive movements of the muscles of the throat and lower part of the face, but more especially of the throat, were observed on pinching these nerves with the forceps. On cutting the nerve across, the same convulsive movements and indications of suffering were no¬ ticed on pinching the nerve on the proximal end, or that part of the nerve which retained its natural connection with the medulla oblongata. These convulsive movements were exactly similar to those observed when the nerve was entire. There were no con¬ vulsive movements on irritating the lower end by the forceps. Exp. V.—-The nerve was exposed on one side in a middle- sized full-grown pointer. When irritated by pinching it firmly with the forceps, only very feeble convulsive movements of the throat were excited, and such as would readily have escaped no¬ tice, had we not been in search of them. Professor Sharpey of the London University College, was present from the commence¬ ment of this experiment, and as we were proceeding to expose the nerve of the opposite side, we were joined by Professor Alison. On irritating the opposite nerve by pinching it with the forceps, the convulsive movements of the muscles of the throat were dis¬ tinctly marked, but still in a less decisive manner than in some of the preceding experiments. The nerve was then included firmly in a ligature. On irritating the nerve on the proximal side of the ligature, the same convulsive movements followed ; while no effect was observed from the irritation of the nerve on the distal side, or that in connection with the tongue and pharynx. The same difference in the results was also obtained from the irritation of the two ends of the nerve when cut across. We had in this dog an opportunity of contrasting the manner in which muscular move¬ ments are induced through the stimulation of a motor nerve, such