28 MANUAL OF EQUINE MEDICINE. 



of the veins, as in ascites from cirrhosis of the liver. It 

 also occurs as the result of inflammation, and more rarely 

 of lymphatic obstructions. 



General dropsy is active or passive. 



Active general dropsy is abrupt in its onset, and may 

 result from a chill or other causes. It is widely distributed, 

 and is frequently associated with febrile symptoms. 



Passive general dropsy may be due to heart or renal 

 disease, or ansemia. 



HYPERTROPHY. 



By hypertrophy we mean a quantitative overgrowth of 

 an organ or tissue. The increase is either due to an in- 

 crease in size of the individual tissue elements, or to an 

 increase of their number. In the former case the hyper- 

 trophy is termed simple ; in the latter it is termed numerical 

 hypertrophy. 



Hypertrophy is accompanied by increase in size and 

 weight, and sometimes also by change of shape of the 

 organ. Hypertrophy is regarded as the anatomical ex- 

 pression of increased function. In muscle, for example, 

 v/here it is most commonly met with, the increase of work 

 performed is followed by increase in size of those upon 

 which the strain is thrown. 



Since it helps to maintain the balance between the work 

 to be done and the agent performing it, this hypertrophy is 

 termed 'compensatory.' 



ATROPHY. 



Atrophy is a diminution of the substance of an organ 

 or tissue ; it is thus the reverse of hypertrophy. 



Atrophy is either simple or numerical, according as it is 

 characterized by diminution of the actual size of the tissue 

 elements, or by a diminution of their number. 



