244 



the circulation, forming emboli. Fibrinous thrombi are apt to form 

 upon the roughened surface of the inner coat, or upon the surface of 

 the erosions. 



Fatty degeneration and calcification of the middle and outer coats 

 may occur, and large, hard, calcareous j^lates jDroject inward, upon 

 which thrombi may form or may exist in connection with atheroma 

 of the inner coat. When there is much thickening and increase of 

 new tissue in the wall of the affected artery, it ma}^ encroach upon 

 the capacity of the vessel, and even lead to obliteration. This is 

 often associated with interstitial inflammation of glandular organs. 



Treatment. — Carbonate of potassa in dram doses, to be given in 4 

 ounces liquor acetate of ammonia every six hours. Scalded bran 

 sufficient to produce loosening of the bowels, and complete rest. 

 Externally, applications of hot water or hot hop infusion. 



ATHEROMA. 



Atheroma is a direct result of an existing chronic endarteritis, the 

 lining membrane of the vessels being invariably involved to a greater 

 or less degree. It is most frequently found in the arteries, altjiough 

 the veins may develop an atheromatous condition when exposed to any 

 source of prolonged irritation. Atheroma may affect arteries in any 

 part of the body; in some instances almost every vessel is diseased, in 

 others only a few, or even parts of one vessel. It is a very common 

 result of endocarditis extending into the aorta, which we find perhaps 

 the most frequent seat of atheroma. As a result of this condition the 

 affected vessel becomes impaired in its contractile power, loses it nat- 

 ural strength, and in consequence of its inabilitj- to sustain its accus- 

 tomed internal pressure, undergoes, in many cases, dilatation at the 

 seat of disease, constituting aneurism. In an atheromatous vessel, 

 calcareous deposits soon occur, which render it rigid, brittle, and sub- 

 ject to ulceration or rupture. In such vessels the contractility is 

 destroyed, the middle coat atrophied and bej'ond repair. Atheroma 

 in the vessels of the brain is a frequent cause of cerebral apoplexy. 

 No symptoms are manifested hy which we can recognize this condition 

 during life. 



CONSTRICTION OF AN ARTERY. 



This is usually the result of arteritis, and may partly or wholl}^ be 

 impervious to the flow of blood. AVhen this occurs in a large vessel it 

 may be followed by gangrene of the j)arts ; usually, however, collateral 

 circulation will be established to nourish the parts previously supplied 

 by the obliterated vessel. In a few instances constriction of the aorta 

 has produced death. 



ANEURISM. 



Aneurism is usually described as true and /a/w. True aneurism is 

 a dilatation of the coats of an artery over a larger or smaller part of 



