Histology; normal and morbid.
- Dunham, Edward K. (Edward Kellogg), 1860-1922
- Date:
- 1898
Licence: Public Domain Mark
Credit: Histology; normal and morbid. Source: Wellcome Collection.
Provider: This material has been provided by the Augustus C. Long Health Sciences Library at Columbia University and Columbia University Libraries/Information Services, through the Medical Heritage Library. The original may be consulted at the the Augustus C. Long Health Sciences Library at Columbia University and Columbia University.
92/466 page 96
![processes is an axis-cylinder process. Tlie multipolar cells have one axis-cylinder process, the rest being of the dendritic type already mentioned, which are distinguished as '^protoplasmic processes. Xerve-cells are, as a rule, larger than the other cytoplasmic cells of the body, with the exception of the larger epithelial cells. Their cytoplasm is so finely granular that the cells look much more trans- parent than those of epithelium. With a high power the cytoplasm frequently exhibits fine striations, which are prolonged into the processes, giving them an appearance of longitudinal fibrillation. These appearances are due to the arrangement of the fibrils of spongioplasm. Considerable attention has of late been given to certain granules, which become evident in the cytoplasm when nerve-cells have been fixed in alcohol or in acid solutions. These granules have an affinity for dyes, chroraophilic granules, and usuallv occur in groups in the neighborhood of the nucleus. Their significance is not yet understood. The protoplasmic processes of the nerve-cells diminish in diam- eter as they branch, and they also present occasional varicosities, which give them an irregular contour. They terminate either in fine-pointed extremities or in little, knobbed ends, and do not unite with those of neighboring cells, but form with them an intricate interlacement of delicate nervous twigs. The axis-cylinder processes arise in conical extensions of the cell, and then become uniform in diameter and of a smooth contour without varicosities. When tliey l^ranch the two divisions retain their size throughout their course until they enter into the forma- tion of some terminal structure. The average size of the nuclei of nerve-cells is greater than that of the other nuclei in the body, but they appear to contain less chromatin, and therefore stain less deeply and present a less distinct intranuclear reticulum. Nerve- or ganglion-cells are found in the gray matter of the central nervous system, in the ganglia, and sometimes in the course of nerves and in their peripheral terminations (Fig. 82). 2. Nerve-fibres.—There are two varieties of nerve-fibres : the white, or niedulhited, and the gray, or non-mcdullated. These differ both in their appearance when seen by the unaided eye and in their micr()sco])ical structure. (a) Medullated nerve-fibres consist of a central cylindrical struct-](https://iiif.wellcomecollection.org/image/b21223841_0092.jp2/full/800%2C/0/default.jpg)
