The anatomy of the nervous system, from the standpoint of development and function . ion transverse to the long axis of the enter the cord from the pia mater and are accompanied by con- THE SPINAL (OKI) 87 nective tissue from the pia and by the subpial aeuroglia. It has been generallysupposed that the white Fascicles of the cord were composed almosl exclusivelyof myelinated Gibers; and it is true that these, parti) because of their size, arethe most conspicuous elements. In cross-sections stained In the Weigertmethod the myelin sheaths alone are stained; and since th
The anatomy of the nervous system, from the standpoint of development and function . ion transverse to the long axis of the enter the cord from the pia mater and are accompanied by con- THE SPINAL (OKI) 87 nective tissue from the pia and by the subpial aeuroglia. It has been generallysupposed that the white Fascicles of the cord were composed almosl exclusivelyof myelinated Gibers; and it is true that these, parti) because of their size, arethe most conspicuous elements. In cross-sections stained In the Weigertmethod the myelin sheaths alone are stained; and since the fibers are cut atright angles to their long axes, they appear as rings. Cajal (1009) has shownthat there are also great numbers of unmyelinated fibers in the longitudinalfascicles of the cord (Fig. 62). The different Fascicles differ not only in the sizeof their myelinated fibers but also in the proportion of unmyelinated fiberswhich they contain. The fasciculus dorsolaterals or tract of Lissauer (Fig. 63)contains fine myelinated fibers with great numbers of unmyelinated Fig. 63.—From a cross-section of the spinal cord of the cat; a narrow strip extending acrossthe apex of the posterior gray column: a, Fasciculus cuneatus; b, fasciculus dorsolateralis (Lis-sauer); c, dorsal spinocerebellar tract. The unmyelinated fibers appear as black dots. Pyridin-silver method. Close to it lies the dorsal spinocerebellar tract which is composed almost ex-clusively of large myelinated fibers. Gray Substance.—The gray matter is composed of nerve-cells, includingtheir dendrites, and of unmyelinated axons and smaller numbers of myelinatedfibers—all supported by a neuroglia framework and richly supplied with capil-lary blood-vessels. The axons of the cells of Golgis Type I are very long andrun out into the white substance or into the ventral roots. Those of the cellsof his Type II are short and end within the gray matter. In addition, greatnumbers of collaterals from the dorsal ro
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectnervoussystem, bookye
