On the physiology of the semicircular canals and their relation to seasickness / by Joseph Byrne.

  • Byrne, J. Grandson (Joseph Grandson), 1870-1945.
Date:
1912
Catalogue details

Licence: Public Domain Mark

Credit: On the physiology of the semicircular canals and their relation to seasickness / by Joseph Byrne. Source: Wellcome Collection.

Provider: This material has been provided by the Augustus C. Long Health Sciences Library at Columbia University and Columbia University Libraries/Information Services, through the Medical Heritage Library. The original may be consulted at the the Augustus C. Long Health Sciences Library at Columbia University and Columbia University.

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    and that no fibres from the sixth or third nucleus enter the posterior longitudinal fasciculus. The fibres of the posterior longitudinal fasciculus to the sixth nucleus more probably represent efferent cerebellar or other paths which, with similar fibres or collaterals passing from the cerebellimi or other centre to the third and fourth nucleus, afford a more rational explanation of the coordinated action of these nuclei. Moreover, v. Bechterew^^ con- siders the cerebellar superior olivary tract which, through the superior olives, makes connection with the sixth nucleus as an efferent cerebellar jy-cith for ocular move- ments. In a similar way, perhaps, may be explained the coordinated relation of the seventh and third, as well as of the other cranial nerve nuclei. 5. With the cerebellum. These paths have not been satisfactorily demonstrated, v. Bechterew states that a continuous connection exists between the third nucleus and the cerebellum, by which the latter becomes in- structed as to the position of the eyeballs and the condi- tion of the pupil. These pathways lie in the superior peduncle of the opposite side. The relation, therefore, between the oculo-motor nucleus and the cerebellum is a crossed one. V. Bechterew, ^^ however, in discussing the centrifugal function of the spinal bundle of the middle peduncle and of the cerebellar superior olivary tract, states that the fibres passing in the superior peduncle to the oculo-motor nucleus of the opposite side are also cerebello-efferent for the control of reflex ocular movements. The relations of the third nucleus to the seventh and to the other cranial nerve nuclei are probably mainly through the cerebellum via the superior peduncle, and thence through efferent cerebellar paths, including those in the posterior longi- tudinal fasciculus. The fourth nucleus lies near the middle line, just caudad to the third nucleus, from which it is separated by a small intfjrval. It seems to lie in a distinct depres- sion on the posterior longitudinal fasciculus. It is 2 mm long, and ext(m(ls from a point oy)posite the superior fxjrder of the inferior colliculus. to the lower ])ole of the colliculus. It is in relation with the cortex of thf? inferior