. The elements of pathological histology with special reference to practical methods . truction of theglobe of the eye or optic nerve, is also apt to be followed by anatrophy in the corresponding portions of the central nervous system,an atrophy which may involve the ganglion cells as well as the ATROPHY AND SOFTENING 338 paths of conduction. Lastly, a primary atrophy of ncrvc-jihres alsooccurs in the brain under certain circumstances, as after insolationand in general paralysis (see p. 342). Softening of the brain and spinal cord is a necrosis due to dis-orders of the circulation setting in e
. The elements of pathological histology with special reference to practical methods . truction of theglobe of the eye or optic nerve, is also apt to be followed by anatrophy in the corresponding portions of the central nervous system,an atrophy which may involve the ganglion cells as well as the ATROPHY AND SOFTENING 338 paths of conduction. Lastly, a primary atrophy of ncrvc-jihres alsooccurs in the brain under certain circumstances, as after insolationand in general paralysis (see p. 342). Softening of the brain and spinal cord is a necrosis due to dis-orders of the circulation setting in either suddenly or gradually(embolism, vascular disease, compression), or to mechanical destruc-tion, and the process is called white or red (or yellow) softeningaccording as it runs its course without or with hsemorrhages.(The softening brought about in the spinal cord by compression isalso called compression or contusion myelitis.) In the first instancethe ganglionic cells and the nerve-fibres undergo necrosis (the formernot uncommonly swelling up and becoming hyaline, or vacuoles. Fig. 160.—Atrophy of the Anterior Horns of the Spinal Cord in Chronic;Anterior Poliomyelitis, x 545. (Alum cochineal.) A, Anterior column ; B, Anteriorhorn ; a. Ganglion cell with processes ; b, Atrophic ganglion cells ; c, Atrophic ganglioncells with pigment; d, Corpus aniylaceum ; c, Nuclei of neuroglia cells. forming in them), whilst finally they dissolve altogether. The ganglioncells may also, however, undergo fatty degeneration, and when oncedead, may even calcify. In the nerves it is the medullary sheath which is most breaks up into drops of variable size and of very numerous andstrangely outlined forms, these drops being still at the outset com-posed of myelin, though later, as they become smaller and smaller, it isimpossible to distinguish them from fat-droplets. The axis cylindersmay remain unaltered for a longer time, or may swell up or becomevaricose. Within the limits of t
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectpatholo, bookyear1895
