ATROPHY, DEGENERATION, PIGMENTATION, AND NECROSIS. 



79 



distinct. In simple atrophy, under whatever conditions it may occur, the 

 tissue elements become smaller without marked alterations in structure, 

 and may finally disappear altogether. In the majority of cases, how- 

 ever, atrophy of cells or other tissue elements is not simple but is asso- 

 ciated witETand often determinedHS'y, various^ phases of Regeneration 

 degenerative atrophy. 



Degeneration. 



ALBUMINOUS DEGENERATION (Cloudy Swelling, Parenchymatous De- 

 generation, Acute Degeneration, Granular Degeneration). 



Under a variety of conditions in which there is a disturbance of tis- 

 sue nutrition, but especially often in infectious diseases and in intoxica- 

 tions when poisonous substances come in contact with the tissues, the 



FIG. 15. ALBUMINOUS DEGENERATION. KIDNEY. 

 The lesion is moderate in degree and is most marked in the largest tubule above. 



cells of the body show an accumulation in the cytoplasm of albuminous 

 granules, of various sizes and forms. This is a type of cell degeneration 

 which is so often associated with infectious diseases and certain phases 

 of inflammation, that it is sometimes regarded as a part of the inflam- 

 matory process. The cells in this condition are usually swollen and are 

 more opaque than normal, the nucleus being somewhat concealed in the 

 granules when these are numerous (Fig. 15). The albuminous granules 

 in the cells are soluble in dilute acetic acid but not in ether, being thus 

 distinguished from fat. 



While all the cells of the body are subject to this phase of proto- 

 plasmic degeneration, it is most pronounced and frequent in the paren- 

 chyma cells of the liver and kidney, in muscle, in epithelial cells of the 

 mucous membranes. These are, it will be seen, cells in which metabolism 

 is active and the exigencies of nutrition are imperative. The alterations in 

 the ganglion cells of the central nervous system in infectious diseases and 



