Parciichyiiiafous Iii/hunination. 287 



Parenchymatous, Degenerative Inflammation.— The inflammatory pro- 

 cesses almost exclusively run their course in the vascular connective 

 tissue of the organ; the other constituents, gland cells, muscles or nerves, 

 take a more or less passive part. Inasmuch, however, as there may often 

 be noted in the tissue elements constituting the organic parenchyma 

 mitntivc disturbances and regressive metamorphoses, either as primary 

 changes produced by the cause of the inflammation, or as secondary 

 alterations, due to the inflammatory process itself, it has become more or 

 less customary to speak of such instances under the names parenchymatous 

 or degenerative inflammatiou. Due to the action of irritants which 

 primarily cause inflammatory changes in the interstitial tissue, there often 

 occur such changes as cloudy swelling, fatty degeneration or necrosis m 

 parenchymatous organs like the liver, kidneys or brain, of so marked a 

 character that the real signs of inflammation in these cases almost entirely 

 disappear, and perhaps can only be demonstrated by means of the micro- 

 scope. The process and condition might well be summarily relegated, 

 because of its principal features, to the degenerations. As the type of the 

 degeneration is sometimes a complex one, made up of a number of forms 

 of regressive changes, it is customary when some of the other features 

 of inflammation coexist (hypersemia, swelling, induration) and the gross 

 anatomical picture does not necessitate their separation, to employ the 

 term "degenerative inflammation" for the combination of the two processes. 

 [The editor feels that here too much stress is laid upon the passivity 

 of the parenchymatous tissues in inflammation. They are, it is true, not 

 the elements which strikingly react in the process, and their regressive 

 changes are usually much more apparent than their active participation. 

 Yet they do react and in practically the same way, as by proliferation, to 

 some degree in this or that inflammatory process. A hepatitis is more 

 apt, it is true, to exhibit the liver cells swollen and granular, yet occa- 

 sionally there are found cells with karyokinetic figures in their 

 nuclei ; direct nuclear division is not infrequently seen in the nuclei of 

 muscle fibres in the case of myositis ; the axis cylinder buds in the 

 inflammation caused by traumatic injury of a nerve, or the new growth 

 of muscle spindles in the inflammation about a similar lesion of muscular 

 tissue, argue to the same end. Proliferation commonly takes place in 

 the epithelium of an inflamed mucous membrane or in a gland, and while 

 parenchymatous cells probably take no part in ordinary encapsulation of 

 foreign bodies, they may take part in elimination. They probably exert 

 no unimportant part in the destruction or dimunition of virulence of 

 many toxic chemicals, as is a generally accepted function of the liver ; 

 and their aid in excretory elimination from the body of the same type 

 of irritants, and in a minor measure of particulate elements, as unfit and 

 perhaps harmful albuminous granules, cannot be overlooked. That they 

 are in a way phagocytic is evinced by their assumption of pigment 

 material, changing it, i^ is true, in many cases by their metabolic activity. 

 A microorganism may lodge upon some epithelial cell on a mucous sur- 

 face, on a duct, or even in an acinus of some gland, and fail to be dis- 

 lodged. The cell may react to the irritant microbic influences by pouring out 

 a volume of secretion, possibly mucus, in which the microorganism is 



