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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    and of the trunk in consequence. The whole active machinery of the frame is in most intmiate union. If we consider the office of the eyes—the necessity for their free and uncon- trolled motions—their sole dependence on the sensation in the retina—we shall be ready to acknowledge that they must be relieved from the train of concate- nated actions which occurs in every movement of the frame besides. Thus unem- barrassed, the recti muscles of the eye are suited to that sympathy, and that ex- traordinary minuteness of accordance with the state of sensation in the retina, which are necessary to vision. Resuming the consideration of the columns of motion and sensation:—they may be traced up into the cerebrum; the great crus cerebri is formed of these combined columns, as each diverges, and is lost in the hemisphere. The column of motion is still anterior, so that the anterior part of the crus belongs to mus- cular action, and the posterior part to sensation. Now, considering that the essential difference in these columns is this—that in the anterior, the course of impulse is outward from the sensorium commune, and inwards, or towards the sensorium in the posterior, the origins of all the nerves must conform, or the system is overthrown. We look with increasing interest on the roots of nerves, as conclusive on this subject. The first nerve, the olfactory, being traced backwards, divides into three roots, and disperses in the inferior part of the anterior lobe of the cerebrum, without the intervention of the columns, and without interference with them. The second or optic nerve, though in direct contact with the column of mo- tion, takes no origin from it; but in a long and circuitous course, under the name of Tractus opticus, turns round the crus cerebri, to fall into the rear or back part of the column of sensation; and so, is combined with those nerves, through which the impulse is towards the sensorium, or inwards. Even on proceeding so far, it is fair to infer that a nerve of sense gives off no branch—that it can communicate no endowment—that it is unequal to con- fer either motion or sensation, or any property but that which is its limited of- fice. Further, if we take the pen, and trace the nerves of sense—the olfactory, optic, auditory, and gustatory—we shall find them all avoiding the anterior co- lumn, and falling into the back part of the sensitive column; so that already in part we perceive the cause of irregularity in the base of the brain, in the neces- sity of the nerves of sense avoiding the anterior column, to gain the posterior or sensitive column. We come next to the Third Nerve. This nerve is distinguished from all others; its origin is peculiar, and its distribution limited. By universal consent, it has got the name of motor ocxdi, being distributed to the voluntary muscles of