Chambers's encyclopaedia; a dictionary of universal knowledge . ar, an ascending antero-lateral tract, a crossed ]iyramidal tract, a laterallinuting layer, and a lateral mixed zone ; while theanterior column consists of a ilirect jjyramidaltract and an anterior mixed zone. The relationsof these tracts have been fairly delinitely estab-lished. The posteromedian cohinin is nearlyentirely composed of libres of the posterior rootswhich, after entering the cord and for ashort distance in the postero-exlernal column, arecontinued upwards as high as the medulla oblon-gata, where they end. Th
Chambers's encyclopaedia; a dictionary of universal knowledge . ar, an ascending antero-lateral tract, a crossed ]iyramidal tract, a laterallinuting layer, and a lateral mixed zone ; while theanterior column consists of a ilirect jjyramidaltract and an anterior mixed zone. The relationsof these tracts have been fairly delinitely estab-lished. The posteromedian cohinin is nearlyentirely composed of libres of the posterior rootswhich, after entering the cord and for ashort distance in the postero-exlernal column, arecontinued upwards as high as the medulla oblon-gata, where they end. This column tlien will forma direct path of connection of the posterior rootswith the medulla oblongata. The direct cerebellartract connects a column of nerve-cells in the pos-terior horn of the lumbar and dorsal regions of thecord {which is termed tlarkes vesicular column)with the middle lobe of the cerebellum. Theanterolateral tract appears to connect the neive-cells in the posterior horn of one side of the cordwith the medulla oblongata of the opposite from the cerebrum and from the posterim-roots an<l other . In the posterior horn the Fig. 2.—Section of Spinal Cord (outline of tracts shown on left side):anterior liieiliaii fissure; 2, posterior inediuii septum; :i, 4, 5. anterior, lateral, andl^ti^terior white coluiuiis ; 6, 7, anterior and posterior liorn of gray matter ; 8, 9, anteriorand posterior coniinissiu-es : 10, posterior median column; 11, posterior lateral column ;J2, direct cerebellar tract; 13, antero-lateral ascending tract; 14. crossed pyramidaltract; 15. lateral limiting layer; IG, 17, lateral and anterior mixed zone; tract; 19, posterior, and 20, anterior roots. All these tracts degenerate, and presumably alsociuiduct nervous imjiulses in an u|iwaid diiect and crossed iiyranddal tiucls form thedownward continuation of the • motor libres fromthe surface of the biain to the cells in the anterior
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Keywords: ., bookcentury1900, bookdecade1900, bookpublisherlondo, bookyear1901
