A manual of anatomy . ve a longitudinal course. In the area just dorsal to the pons fibers are the pyramids, twolarge compact bundles of longitudinal fibers on their way to theoblongata. Some of these fibers terminate in the nuclei pontisrepresenting cerebropontile fibers. Dorsal to the pyramids are seen avariable number of deeper transverse pontile fibers. The arcuatefibers and nuclei of the oblongata are analogous to the pons fibers andpontile nuclei. Dorsal to the pons lie the fibers of the medial lemniscus forming a26 402 THE NERVE SYSTEM rather compact bundle upon each side of the raphe.


A manual of anatomy . ve a longitudinal course. In the area just dorsal to the pons fibers are the pyramids, twolarge compact bundles of longitudinal fibers on their way to theoblongata. Some of these fibers terminate in the nuclei pontisrepresenting cerebropontile fibers. Dorsal to the pyramids are seen avariable number of deeper transverse pontile fibers. The arcuatefibers and nuclei of the oblongata are analogous to the pons fibers andpontile nuclei. Dorsal to the pons lie the fibers of the medial lemniscus forming a26 402 THE NERVE SYSTEM rather compact bundle upon each side of the raphe. In higher sec-tions these lemnisci diverge from the midline to make room forthe trapezium. Pars Dorsalis Pontis.—The lemnisci separate the pons proper fromthe pars dorsalis pontis (preoblongata). Dorsal to the outer sideof the lemniscus is seen the central tegmental tract and the superiorolivary nucleus connected with the fibers of the trapezium (acousticfibers). Between the superior olivary nucleus and the formatio. Fig. 289.—Diagram of the nuclei of the cerebral nerves in the brain stem (dorsal view).Motor nuclei in solid black, sensor nuclei dotted. reticularis lies a bundle of fibers {trapezial) that form the trapeziumof the next level. This portion shows also th^ formatio reticularis oneach side of the raphe with the median longitudinal bundle in its dor-sal area; between the formatio reticularis and the cavity of the ven-tricle is the ventricular gray substance in which are seen certain cere-bral nerve nuclei. Near the midline is seen the nucleus insertus (Streeter) that con-tinues up to the aqueduct. To the side of this lies the nucleus of theabducens nerve; lateral to this the principal vestibular nucleus is notedand beneath the gray the descending root of the vestibular nerve; atthe dorsal margin lies the upper end of the restiform body. Deeper THE INTERNAL ANATOMY OF THE PONS REGION 403 ventrad and over the superior olivary nucleus is the nucleus of thefacial nerv


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Keywords: ., bookcentury1900, bookdecade1910, booksubjecthumananatomy, bookyea