Injury to the endothelium -atherosclerosis is initiated by damage to the endothelial cells, which exposes the subjacent connective tissue (subendothelium). the loss of the antithrombogenic endothelium results in aggregation of platelets. atherosclerosis is one form of arteriosclerosis (hardening of the arteries) that involves deposition of fatty material primarily in the walls of the conducting arteries. the intima and media become infiltrated with lipid. intimal thickening occurs through the addition of collagen and elastin with an abnormal pattern of elastin cross-linking. platelets release mitogenic substances that stimulate proliferation of smooth muscle cells. the thickening of the intima is also called an atheromatous plaque and worsens with repeated damage to the endothelium. it is most dangerous in small vessels, particularly the coronary arteries, where occlusion can result in a myocardial infarction. atherosclerotic plaques also lead to thrombi and aneurysms.
