A text-book of physiology - for medical students and physicians (1916) (14769883212)
Summary
Identifier: textbookofphysio1916howe (find matches)
Title: A text-book of physiology : for medical students and physicians
Year: 1916 (1910s)
Authors: Howell, William H. (William Henry), 1860-1945
Subjects: Physiology Medicine
Publisher: Philadelphia and London : W. B. Saunders Company
Contributing Library: Yale University, Cushing/Whitney Medical Library
Digitizing Sponsor: Open Knowledge Commons and Yale University, Cushing/Whitney Medical Library
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and the cerebellum, present amechanism which may be used to explain the influence exercisedby the cerebellum upon muscular activity. 2. Connections with the Vestibular Branch of the Eighth Cran-ial Nerve.—This branch, arising in the semicircular canals andutriculus and sacculus, ends in the pons in several nuclei (Deiters,Bechterews) and also in the n. fastigii of the cerebellum. Thesenuclei, in turn, are connected with other parts of the centralnervous system, but the details are not yet completely known.The connections that have been most clearly established arethose made with the motor centers. Through the medial longi-tudinal fasciculus these nuclei are connected with the motornuclei of the cranial nerves and with descending paths in the spinal 236 PHYSIOLOGY OF CENTRAL NERVOUS SYSTEM. cord (vestibulospinal), which end in the motor centers for the spinalnerves. In how far the vestibular nuclei may make afferent con-nections with the cerebellum is undecided, but it seems probable
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Fig. 104.—Diagram to indicate a possible descending path from cerebrum to cord in ad-dition to the pyramidal system, namely, the secondary or cerebellar motor path (VanGehuchten). The path is indirect and comprises the following units: 1. The cortico-ponto-cerebellar path, represented as arising in the motor area of the cerebrum and passingdown with the pyramidal system to end in the pons, thence continued through the middlepeduncles to the cerebellar cortex of opposite side. 2. The path from the cerebellar cortexto the dentate nucleus. 3. The path from the dentate nucleus to the red nucleus passingby way of the superior peduncles, brachium conjunctivum. 4. The path from the rednucleus to the motor cells of the spinal cord (rubro-spinal tract). that such tracts exist, in view of the fact that destruction of thesemicircular canals and severe lesions of the cerebellum cause motordisturbances that are strikingly similar. 3. Connections with Other Sensory Nuclei.—In addition to thespe