A manual of anatomy . sections. Near the side are seen the nucleus andlibers of the spinal root of the trigeminal nerve. Pons and Pars Dorsalis Pontis.—This portion of the brain stem isequivalent to the oblongatal part plus a broad and thick band oftransverse fibers ventrally placed; the latter fibers constitute the THE INTERNAL ANATOMY OF THE PONS REGION 401 pons. This part of the brain wiU be considered in three sections:(i) lower, (2) middle and (3) upper. I. If a section at the lower ejid be examined the ventral partwill be seen to consist of a rather thick mass {pars basalis ponds)of tran
A manual of anatomy . sections. Near the side are seen the nucleus andlibers of the spinal root of the trigeminal nerve. Pons and Pars Dorsalis Pontis.—This portion of the brain stem isequivalent to the oblongatal part plus a broad and thick band oftransverse fibers ventrally placed; the latter fibers constitute the THE INTERNAL ANATOMY OF THE PONS REGION 401 pons. This part of the brain wiU be considered in three sections:(i) lower, (2) middle and (3) upper. I. If a section at the lower ejid be examined the ventral partwill be seen to consist of a rather thick mass {pars basalis ponds)of transversely coursing fibers, the pons, and two large bundles oflongitudinal fibers, the pyramids. In among these fibers are seencollections of nerve cells called the nuclei pontis. The transversefibers are more abundant in man than in any other animal. Most ofthem lie ventral to the pyramidal tracts and serve to connect thecerebellar hemispheres with each other. At the lateral boundaries Nucleus globosus Nucleus tecti. Nucleus einboliform^s Nucleus dentatus Bechterews nucleusDeiters nucleusSpinal root of V nerve 7 s Nucleus of VII nerve Superior Thalamolivolive ary tract _^_^__ Brachium ?t t i-^ conjunctivuni ._ ? Corpus re tiformc Nucleus VI nerve^XM^J^ Bra-hium pontis VI11 nerve Fig. Pons Pyramid Medial lemniscusSection of the lower part of the pons rc^^ion. of the pons these fibers are collected into a compact bundle thatenters the corresponding cerebellar hemisphere as the middle pedun-cle {bracJiium pontis). Some of the pons fibers end around the cellsof the pontile nuclei of the same side and some go to the opposite side;new fibers then arise from these cells and continue to the cerebellarhemisphere. Some of the cells of the nuclei pontis are also way-sta-tions in the pathway of cerebropontile fibers and new fibers arisinghere pass to the cerebellar hemispheres. These cerebropontile fibershave a longitudinal course. In the area just dorsal to the pons fibers are the pyrami
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Keywords: ., bookcentury1900, bookdecade1910, booksubjecthumananatomy, bookyea
