Human anatomy, including structure and development and practical considerations . o be composetl of iniuunerable, closely set, small cells, heldtoii^ether by delicate supportniii;- tissue. These ai)j)arent cells are the niedullatcdnerve-fibres cut transversely, in which the sectioned axis-cylinders show as deeplystained dots, that commonly lie somewhat eccentrically and are surrounded by deli-cate irrei^ularly annular striations representing the framework of the medullary c< ncrve-tibres of the cerebro-spinal axis are without neurilemma, the lack of thissheath beiuir compensated l)y
Human anatomy, including structure and development and practical considerations . o be composetl of iniuunerable, closely set, small cells, heldtoii^ether by delicate supportniii;- tissue. These ai)j)arent cells are the niedullatcdnerve-fibres cut transversely, in which the sectioned axis-cylinders show as deeplystained dots, that commonly lie somewhat eccentrically and are surrounded by deli-cate irrei^ularly annular striations representing the framework of the medullary c< ncrve-tibres of the cerebro-spinal axis are without neurilemma, the lack of thissheath beiuir compensated l)y a slitjht condensation of the neurog^lia around thefibres. Seen in trans\erse sections this iiuestment a])pears as the rin^- that givesa definite outline to the fibre. Tile iiitlividual nerve-fibres vary i^reatly in size, even within the same tract and smallfibres often : side by side. Tlie smallest may be less than .cx)5 mm. and the larjjest mm. In a general way, the diameter of the fibre bears a direct relati(jn to its length, those Fig. 892. ^ ^ ft\ ^. .Trabeiula oi neuruglia Neuroglia cell Ner\e-lihre Blood-vessel in pia Subpial layerof neuroglia Peripheral part of transverse section of spinal cord, showing nerve-fibres subdivided into groups by ingrowth of subpial layer of neuroglia. >; 230. having an extended course being larger than shorter ones ; it follows that the fibres occupyingthe peripheral parts of the white matter, particularly in the lateral columns, are more frequentlyof large diameter than those near the gray matter. The immediate surface of the white substance beneath the pia mater is formed by a con-densed tract of neuroglia, the subpial layer, from . mm. in thickness, that is devoid ofnervous elements and forms the definite outer boundary of the cord. This zone consists of adense interlacement of circular, longitudinal and radial neuroglia fibrils among which numer-ous glia cells are embedded. From the deeper surface of th
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Keywords: ., bookauthormc, bookcentury1900, bookdecade1910, booksubjectanatomy
