. Diseases of the nervous system . Fig. 85.—Diagram of the Course of theSensory Tracts from the PosteriorRoots to the Medulla. (After Edin-ger.) 90 HISTOLOGY OF THE CENTRAL NERVOUS SYSTEM form the second neuron, sends its fibers through the raphe to the most dorsalregion of the crossed lemniscus. The same is true of the nucleus of the glosso-pharyngeal nerve. (Probably the ascending roots of the glosso-pharyngealand vagus send crossed fibers into the lemniscus tract; no positive knowledgeconcerning this is at hand.) The relations of the auditory nerve are more complicated. These ariseat the he
. Diseases of the nervous system . Fig. 85.—Diagram of the Course of theSensory Tracts from the PosteriorRoots to the Medulla. (After Edin-ger.) 90 HISTOLOGY OF THE CENTRAL NERVOUS SYSTEM form the second neuron, sends its fibers through the raphe to the most dorsalregion of the crossed lemniscus. The same is true of the nucleus of the glosso-pharyngeal nerve. (Probably the ascending roots of the glosso-pharyngealand vagus send crossed fibers into the lemniscus tract; no positive knowledgeconcerning this is at hand.) The relations of the auditory nerve are more complicated. These ariseat the height of the pons in the median portion of which, above the pyramidal Radix anterior Central motor path of conductionMotor nerve cell Sensory collaterals (reflex collaterals) Peripheral motor nerve fiber Peripheral motornerve terminal Peripheral sensory nervefiber Peripheral sen sory nerve terminal. ^JRadix posterior Ascending and de-scending branch ofthe sensory rootfibers Sensory collaterals 5* Tract cell and tractfiber Fig. 86.—Diagram of the Motor and Sensory Conduction Tracts (Reflex Arcs). (After Toldt.) tract, the lemniscus tract passes upward. The nuclei of the acoustic nervehave been described (Figs. 88, 89, 94, 95). The ventral nucleus, situatedventrally and laterally near the entrance of the nerve, contains some of thesecond neuron cells. These fibers pass horizontally and medially through thepons between the pyramidal and lemniscus tracts, and cross to the otherside. This tract is called the corpus trapezoideum (Figs. 88, 89, 95).Large numbers of nerve-cells are here deposited. Directly above them dor-sally and immediately below the nucleus of the facial nerve is a small col-lection of ganglia, the upper olive, into which large numbers of these fiberspenetrate. Many fibers of the corpus trapezoideum appear to split up around theirown cells as well as around the cell
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectnervoussystem, bookye
