Three papers on the nerves of the encephalon, as distinguished from those arising from the spinal marrow / by Sir Charles Bell.

  • Bell, Charles, Sir, 1774-1842.
Date:
1838
Catalogue details

Licence: Public Domain Mark

Credit: Three papers on the nerves of the encephalon, as distinguished from those arising from the spinal marrow / by Sir Charles Bell. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    In conclusion, and in explanation of the marked difference in the origin of the nerves of the spine and of the encephalon, we shall find that it is principally owing to the columns of motion and sensation. 1. All the nerves of Sense,—the olfactory, optic, auditory, not excepting the gustatory, though running into the base of the brain, must deviate from the an- terior column, which is that of motion; and, accordingly, they twist round that column to enter directly into the sensorium (as the olfactory does), or to associate with the column of sensation, like the optic tractus, and roots of the auditory nerve. 2. The next source of irregularity of form and apparent intricacy in the base of the brain, is a consequence of the various sensibilities and active powers of the eye and its appendages, which require no fewer than six nerves to this one organ! Hence the ophthalmic of the fifth nerve, in addition to the proper optic nerve,— hence the motor independently of the fifth,—hence the sixth and the fourth, to associate the deep and superficial muscles of the eye and eyelids. 3. Another source of intricacy is the intrusion, as it were, of the fifth nerve among those of the encephalon. The fifth, a nerve of double root, a sensitive and motor nerve, a nerve with a distinct ganglion on its posterior root, I early announced to be a spinal nerve, that is, the anterior or (in the human body) the superior of the spinal nerves. This nerve not only giving motion to the jaws, but being the nerve of sensibility, mingles its branches with every other nerve, goes every where in the head and face, and enters into every organ, and is there- fore a source of exceeding great intricacy, until the just principle be obtained.* 4. Lastly, a main source of intricacy in the nerves of the base of the brain, and of the whole nervous system, is the existence of a distinct source of motion inde- pendent of volition, and yet necessarily conjoined to it,—a source of power which shall govern the act of respiration, and yet permit a union of the apparatus of breathing with those of speech; for example, the necessity of joining the motion of the features with the pneumatic office of the lungs, being the cause of that deviation which we perceive in the facial nerve from those of simple volition. In short the double origin and double function of the nerves of the spine is the reason of their uniformity and simplicity of distribution. The nerves of the brain differ from those of the spine, and from each other, inasmuch as each has a peculiar endowment, and necessarily a distinct origin. They therefore vary in course and distribution, and hence their apparent intricacy. * The discovery of this fact has been caught at by men, as incapable of the induction which led to it, as of following it up in its consequences.