CHAPTER IV. 



DISEASES OF THE CIRCULATORY SYSTEM. 



FIG. 137. 



HEART AND PERICARDIUM. 



ATROPHY. 



Hypoplasia of the heart a congenital smallness is often 

 associated with a similar malformation of the aorta and other 

 bloodvessels, and of the generative organs. This condition 

 has been noted especially in connection with chlorosis. The 

 heart is uniformly affected in all its parts. 



Brown atrophy, an acquired change associated with pigmen- 

 tation, is seen in cases of wasting diseases, as tuberculosis and 



cancer ; and especially also in old 

 age. The heart is dark brown in 

 color, and quite small, often not 

 weighing more than a third of 

 normal ; its walls are thin and 

 cavities contracted. The epicar- 

 dium is frequently wrinkled, the 

 coronary arteries prominent and 

 tortuous, due to the loss of subperi- 

 cardial fat. On microscopical 

 section the muscle-fibres are found 

 to be thinner than normal, and in 

 the centre of each is a brown spot 

 of pigment (Fig. 137). Similar 

 pigmentation is also often asso- 

 ciated with cardiac hypertrophy. 

 The resulting symptoms are not 

 usually serious, as the lessened 

 power of the cardiac muscle is but commensurate with the 

 decreased demand made upon it, 



318 



Brown or senile atrophy of the 

 heart (Ribbert). The muscle- 

 fibres are reduced in diameter; 

 at the ends of the nuclei are col- 

 lections of pigment-granules. 



