Pathology


Categories: Uncategorized
Sources: Disturbances Of The Heart

The pathology of arteriosclerosis is a thickening and diminishing

elasticity of the arteries, beginning with the inner coat and

gradually spreading and involving all the coats, the larger arteries

often developing calcareous deposits or thickened cartilaginous

plates--an atheroma. If the thickening of the walls of the smaller

vessels advances, their caliber is diminished, and there may even be

complete obstruction (endarteritis obliterans). On the other hand,

some arteries, especially if the calcareous deposits are

considerable, may become weakened in spots and dilation may occur,

causing either smaller or larger aneurysms.



Histologically the disease is a connective tissue formation

beginning first as a round-cell infiltration in the subendothelial

layer of the intima. This process does not advance homogeneously;

one side of an artery may be more affected than the other, and the

lumen may be narrowed at one side and not at the other, allowing the

artery to expand irregularly from the force of the heart beat. As

the disease continues, the internal elastic layer is lost, the

muscular coat begins to atrophy, and then small calcareous granules

may begin to be deposited, which may form into plates. In the large

arteries, the advance of the process differs somewhat. There may be

more actual inflammatory signs, fatty degeneration may occur, and

even a necrosis may take place.



However generally distributed arteriosclerosis is, in some regions

the disease is more advanced than in others, and in those regions

the most serious symptoms will occur. The regions which can stand

the disease least well are the brain and coronary arteries, and next

perhaps the legs, at the distal parts at least, where the

circulation is always at a disadvantage if the patient is up and

about.





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