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, 1809-1849.

Date:: [1838]

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.

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

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$branches, distinct convulsive movements of the muscles of the face and throat, and decided indications of suffering were observed. On pricking the nerve during the moaning of the animal, it was several times remarked that the voluntary actions of the muscles of the throat were interrupted by these convulsive starts. This animal Avas killed a few days after, and it was ascertained that while the nerve had been satisfactorily divided on one side, one pretty large pharyngeal branch had been left on the other. Dr Sharpey also examined this dissection, and was fully satisfied of its accuracy. The impression on my mind is, that this pharyngeal twig was found on the left side, (the side first operated on,) but as it is not expressly stated in my notes, I cannot positively af- firm it. Exp. VII.—On exposing the glosso-pharyngeal nerve in a stout tenier bitch, we found that irritation of the lingual branch was at- tended by no visible muscular movements, and no decided indica- tion of suffering; while on irritating some of the small pharyn- geal filaments individually, which leave the trunk of the nerve soon after it leaves \\\e foramen lacerum, convulsive movements of the muscles of the throat and face, and marked indications of suffering followed. It will be unnecessary to detail the results of the other ten expe- riments which were performed to ascertain the effects of irritating this nerve, as far as the indications of muscular movements and com- mon sensation are concerned. I may state, however, that the facts detailed in the above experiments were amply confirmed by those which were subsequently performed. It was found that the mus- cular movements excited by pinching this nerve varied in degree in different animals, but were always distinctly marked when the precaution was taken to irritate the nerve before it had given off its pharyngeal branches. It was also repeatedly observed, that when the nerve was cut across, irritation of the lower end, or that in connection with the muscles, was followed by no movement; while, on the other hand, irritation of the cranial end, even when the nerve was divided before it had given off a single twig, was followed by as powerful convulsive twitches as when the nerve was entire. We also remarked more than once, that while the pinch- ing of the lingual branch caused no muscular movements, irrita- tion of one of the small pharyngeal twigs was followed by very strong convulsive twitches of the throat and lower part of the face. The capability of this nerve to transmit those impressions which excite sensation, was amply proved by the severe and un- doubted indications of suffering which in many cases followed the pinching of it with the forceps. In several cases, however, the indications of suffering were much less strongly marked than in others, but that this nerve possesses common sensation, in the$