458 INANITION AND MALNUTRITION 



chronic inanition. In many chronic disorders, inanition may be an insignificant 

 factor in the earlier stages, but may become increasingly important during the 

 progress of the disease, ultimately constituting the immediate cause of death 

 (Chossat). 



Complications of various kinds may also modify the results of inanition. 

 This is especially true of the infections, which are sometimes characteristic of 

 the later stages (e.g., in xerophthalmia), where the resistance of the organism 

 has been lowered by inanition, either total or partial. Certain phenomena 

 characteristic of inflammation often appear, including cell degeneration, vascular 

 exudates, leukocytic or round cell infiltrations and cell proliferation. These 

 may be due to associated infections, or to toxins set free by the atrophic degen- 

 eration of the tissues during inanition. Visceral hyperemia is characteristic 

 in the later stages of inanition, probably chiefly a passive hyperemia due to 

 cardiac weakness, although Nicolaeff ('23) considers it a hyperemia a vacuo, 

 associated with atrophy of the parenchyma. 



As to species, the effects of inanition are obviously different in plants and 

 animals, between protozoa and metazoa, and between invertebrates and verte- 

 brates. On the whole, the vertebrates appear less plastic and more resistant 

 to inanition, as they are to environmental influences in general. Even among 

 vertebrates, there are often striking differences in the results of inanition in 

 different orders, genera and species. There are also differences according to 

 the age, sex, and even the individual. These differences are due partly to 

 different size and structure of the body, amount of reserve food material, etc., 

 but doubtless depend chiefly upon more fundamental differences in the proto- 

 plasmic structure and composition, upon which the rate and character of the 

 metabolism depend. 



Variation in Parts of the Organism. — It is furthermore clearly apparent 

 that the effects of inanition vary in extent and character in different parts of 

 the same organism. Variable atrophy in different parts of the body may lead 

 to marked abnormalities of form. These variations depend chiefly upon the 

 variable resistance in the constituent organs and tissues. Thus the nervous 

 system and (usually) the skeleton are relatively resistant, while the adipose 

 and lymphoid tissues readily undergo marked atrophy. In general, the ecto- 

 dermal derivatives appear more resistant than the entodermal, and the meso- 

 dermal least resistant. Even in the same tissue, however, the effects may vary 

 greatly in the individual cells. Often scattered groups of cells appear especially 

 affected, perhaps on account of lesser resistance, or of more unfavorable rela- 

 tions to the supply of nutrition. 



Intracellular Variation. — Within the cell, the different cytoplasmic struc- 

 tures vary notably in the extent and character of change during inanition. 

 Thus metaplastic materials, such as glycogen and ordinary fat, usually soon 

 disappear; while the mitochondria are relatively persistent. The nucleus is 

 relatively more resistant than the cytoplasm, as was noted by Pfitzner ('86), 

 thereby increasing the "nucleus-plasma ratio." Mitosis is usually suppressed 

 by inanition, but may continue in certain organs or tissues with persistent 

 growth; and there is sometimes (inflammatory?) cell proliferation, especially 



