Narrative of the discoveries of Sir Charles Bell in the nervous system ... / [Alexander Shaw].

  • Shaw, Alexander, 1804-1890.
Date:
1839
Catalogue details

Licence: Public Domain Mark

Credit: Narrative of the discoveries of Sir Charles Bell in the nervous system ... / [Alexander Shaw]. Source: Wellcome Collection.

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    1 ought now, perhaps, before finishing this part of the subject, to draw some further attention to the was aware of this nerve being restricted, in its power of giving motion, to controlling the muscles of mastication. AVithout revert¬ ing to the instance in the text, where it is distinctly shewn that it was that portion of the infraorbitary branch alone which passes to the lips, a part of the organ of mastication, that was supposed to give motion, while the other portions of the same branch that go to the lower eyelid and nostril, which have nothing to do with that organ, were considered to be simply sensitive, I may present another example. Neither the eyebrow nor forehead can be said to form a part of the organ of mastication. It will, therefore, be found, that in experimenting on the supraorbitary branch of the fifth, which supplies these parts, Sir Charles Bell expressly stated that this branch had no power over the muscles. “ I divided,” he says, “ the branch of the fifth pair, which goes to the forehead (supra¬ orbitary), in a man, at his urgent request, on account of tic- douloureux. there followed no paralysis of the muscles of the eyebrow.”—(P. 23.) I may subjoin one or two additional illustrations. “ We have seen,” Sir Charles remarks, “ that when the fifth nerve—the nerve of mastication and sensation — w7as cut in an ass, the animal could no longer gather his food. In the individual whose face was paralysed on one side, during the excited state of respiration, there could be observed no debility or paralysis in the same muscles when he took a morsel into his mouth and began to chew. * * In all animals that havfe a stomach with palpi, or tentacula, to embrace their food, the rudiments of this nerve (the fifth pair) may be perceived ; and always in the vermes, that part of their nervous system is most easily discerned which surrounds the oesophagus near the mouth. If a feeler of any kind project from the head of an animal, be it the antenna of a lobster or the trunk of an elephant, it is a branch of this nerve which supplies sensibility to the member, and animates its muscles. But this is only if it be a simple organ of feeling, and is not, in its office, connected with respiration. From the nerve that comes off from the anterior ganglion of the leech,