20S VETERINARY PATHOLOGY. 



fluence resulting from circulatory disturbances or altered com- 

 position of blood. Diminished oxj'gen supply results in incom- 

 plete o.xidation uf the available intracellular fat which is then 

 accumulated within the cell. Changed environments include the 

 variation of the chemic reaction of a tissue, the tissue tempera- 

 ture, amount of fluid, etc. Disturbance of the environments in- 

 fluences the cell metabolism and maj- cause the union of cleav- 

 age pr(jducts of fat that exist within the cell, or the infiltration 

 and intracellular accumulation of fat may be favored. Changed 

 environments may also render the cells unable to utilize the food 

 brought to them. 



The causes of cloudv swelling are also etiological factors in 

 the production of fatty degeneration, in fact, fatty degeneration 

 is fref|uently associated with cloudy swelling and the fatty de- 

 generation is the result of disturbed metabolism. Disturbed 

 metabolism is produced by insufficient or improper food, dimin- 

 ished suppl_y of oxygen, or inability of the cells to utilize the 

 food or oxygen supplied, the inability of utilization being a re- 

 sult of the damaging influence of chemic or thermic variation 

 of the environments of the cells. 



Appearance. — Vfacroscopic. — A tissue affected wlith fatty de- 

 generation varies in appearance according to the extent of the 

 process. In general, affected tissues are paler in color (change 

 in color is frequently in patches which appear yellowish), lighter 

 in weight (in extreme case, liver tissue affected with fatty de- 

 generation, floats in water), greasy or oily in appearance, (a 

 knife blade that had been used in sectioning a fattv tissue is 

 usually smeared with drops of oil or fat), and usually swollen 

 or enlarged in the early stages, succeeded by diminution in size 

 as the fat is resorbed. Tissues affected with fatty degeneration 

 are less elastic, and more friable. 



microscopic. — In the very early stages the cells contain small 

 granules that are differentiated from the granules of cloudy 

 swelling only by the chemic test referred to above or by special 

 stains, as Sudan Ifl. .\s the degeneration progresses, the minute 

 fat droplets coalesce, forming drops sufficiently large to be rec- 

 ognized microscopically, as small, clear spots or holes in the 

 cell protoplasm in sections of tissue fixed in fluids that are sol- 

 vents for fats and as fat drops in fresh tissues. The affected 

 cells are swollen to an extent which is proportional to the degree 

 of the degeneration. Ultimately the cell membrane ruptures 

 and the enclosed fat is liberated, thus producing a condition not 



