Human anatomy, including structure and development and practical considerations . runk (Fig. 850), the transversely cut individualmeduUated nerve-fibres appear as small circles, sharply defined by a fine outline (theneurilemma), each enclosing a deeply stained dot (the axis-cylinder in section).The interval between the latter and the neurilemma, corresponding to the spaceoccupied by the myelin, usually appears clear and unstained with the exception ofdelicate and uncertain suggestions of membranous septa. In contrast with itsunstained appearance in sections tinged with carmine, after the actio
Human anatomy, including structure and development and practical considerations . runk (Fig. 850), the transversely cut individualmeduUated nerve-fibres appear as small circles, sharply defined by a fine outline (theneurilemma), each enclosing a deeply stained dot (the axis-cylinder in section).The interval between the latter and the neurilemma, corresponding to the spaceoccupied by the myelin, usually appears clear and unstained with the exception ofdelicate and uncertain suggestions of membranous septa. In contrast with itsunstained appearance in sections tinged with carmine, after the action of osmic acidor special hematoxylin staining (Weigert) the medullary substance exhibits a darkcolor and the axis-cylinder appears surrounded by a deeply tinted ring. The neuri- THE NERVOUS TISSUES. 1007 lemma nuclei are occasionally seen as deeply stained crescentic figures that partiallyembrace the nerve-fibre, lying beneath the neurilemma within depressions in themedullary substance. Fig. 850. -0. ( • Perineurium —? - .-- ????.; iJiRy « Endoneurium. >;i:;>:-U:*;^:^^^^ Nerve-fibre Epineurium .lg^ Blood-vessel Transverse section of funiculus composed of nerve-fibres held together by endoneurium andsurrounded by perineurium. X 175. Viewed in cross-section, the nonmeduUated fibres appear as small irregularlyround figures arranged in groups that correspond to bundles (Fig. 851). Whennumerous, the latter are aggregated Fig. 851. Epineurium r--- ;>\\. \ ):^l into secondary bundles betweenwhich extend delicate connective-tissue septa, continuous with thegeneral envelope investing the nerve-trunk. The medullary substancebeing wanting, the pale fibres areof small size and often possess adiameter of less than .001 mm. The Ganglia.—The cell-bodies of the neurones that consti-tute the sensory pathways within theperipheral nerves and of the neu-rones of the sympathetic systemare collected at various points intoaggregations known as examples of t
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Keywords: ., bookauthormc, bookcentury1900, bookdecade1910, booksubjectanatomy
