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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    crosses all the other nerves, and, though crowding with them into the orbit, forms no relation with them, but is altogether given to the abductor muscle.* Again, in following the root of the facialis, and especially that portion of it which arises from the respiratory tract, we find a relation established between it and the root of the fourth nerve or trochlearis; and this delicate nerve passes for- ward like the other, enters the foramen lacerum, and gains the bottom of the or- bit, touches no other nerve, but is wholly given to the superior oblique muscle. If an objection should be made to the circuitous course of these nerves, as the source of the relations between the muscles, how else are the sympathies to be accounted for ? and what interpretation are we to put upon the fact, that wherever there are recti and ohliqui muscles of the eye,—wherever the eye pos- sesses protecting motions, we find the same arrangement of the third, fourth, and sixth nerves, from man downwards.f Surely it is time to read off the anatomy of the nervous system,—to seek for the relations of parts through their nerves,—to ask ourselves why there are such deviations in their course,—and why these deviations are constant, not in indivi- duals only, but in the different classes of animals ? If, with this view, we ask ourselves why the facial nerve takes a course different from the fifth, the func- tions of the part to which it is distributed do sufficiently inform us, that the fea- tures must be joined in sympathy or unison with the act of respiration. If we inquire why its branches reach to the eyelids, to the very part through which the branches of the fifth pass, we have only to notice the necessity for a guarding action of the eyelids in all excited conditions of the respiratory system. I need not here repeat my former observations. In the same manner we may interpret the course of the spinal accessory nerve, or the reverted course of the recurrent of the par vagum. In looking generally to the remarkable deviations in the course of the nerves, we shall find that they are confined to those which join distant parts in the act of breathing, or modify the act of breathing, as in speaking, swallowing, Ac. No such irregularities are found in the system of nerves which minister to voluntary motion and sensation. They are distributed with a perfect symmetry or regu- larity. And in the orbit, if we take away the respiratory of the face (the facialis), and the nerves resulting from that connection, viz. the fourth and sixth, the in- tricacy of the orbitary nerves is removed; there would remain one for vision, another for common sensibility, and a third for motion. * Where there is a retractor muscle, this abducens nerve supplies it, which strengthens the sup- position of a relation between the retraction of the eye and its simultaneous direction inwards. f Taking the facts of the anatomy into account, and the actions of these muscles, the subject be- comes of great interest, as connected with the expression in the eye.