The essentials of medical anatomy / by H.R. Kenwood.

  • Henry Richard Kenwood
Date:
1889
Catalogue details

Licence: Public Domain Mark

Credit: The essentials of medical anatomy / by H.R. Kenwood. Source: Wellcome Collection.

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    cerebri and enter the chiasma; in the chiasma, most of the fibres pass diagonally across to enter the optic nerve of the opposite side; but a few fibres pass di- rectly into the optic nerve of the same side. The nerves leave the chiasma and enter the optic foramina. They furnish the sense of sight. The thirds or Oculo-motor nerves^ arise from the grey matter of the floor of the Sylvian aqueduct, in the region of the superior corpora quadrigemina; the fibres pass forwards, through the tegmentum and the tegmental nucleus, and partly through the substantia nigra, to emerge on the under surfaces of the crura cerebri, close to the pons; a small part of each root often emerges from between the fibres of the crusta, and joins the trunk of the nerve independently. These nerves give branches to all the muscles of the orbit, with the exception of the supei ior oblique and external rectus, also to the sphincter muscle of the iris, and the ciliary muscle of the eyeball. The fourth^ or Trochlear nerves^ arise from a nu- cleus in the region between the superior and inferior quadrigeminal bodies, immediately below that of the third nerve. On the base of the brain, the small nerves are seen passing round the external border of the crura cerebri. They supply solely the superior oblique muscles of the eyeball. The fifths or Trtgemmal nerves, consist each of a