Atherosclerosis, Coronary Artery Disease and Endothelium essays

Atherosclerosis, Coronary Artery Disease and Endothelium essays One of the foremost leaders of mortality in the US is coronary artery disease (CAD). This disease strikes many older men and women, as a result from the infamous factors of high cholesterol, high blood pressure, and diabetes mellitus, not to mention others. Thanks to research over the last decade, there is more understanding of the role endothelium plays in the coronary system. Instead of having non-active, diffusional barrier-like qualities, as was once thought, the endothelium serves many critically important functions. At the blood vessel walls, the endothelium synthesizes and releases active substances such as nitric oxide and bradykinin, two potent regulators of vessel function. It is found that the physiologic changes in the endothelium affect the mechanisms responsible for atherosclerosis, and progressively in coronary artery disease. The changes that generate these conditions are known as endothelial dysfunction. As we will see, even the smallest factors can play a wi despread role in atherogenesis, or the making of degenerative plaques of cholesterol in the inner layer of an artery. Atherosclerosis, a condition increasing with age, is marked by the deposition of lipids into already-present plaques, causing elevated plaques. The inner layer, or endothelium, is the primary site of development of atherosclerosis. The endothelium is a highly dynamic, multifunctional organ whose central role is to respond to changes in stress and blood flow (Jairath, 1999). The endothelium is the largest organ in the body; its total mass is equal to about five human hearts, and surface area about the size of a tennis court. The vascular tone of the blood vessel is maintained by endothelium-released vasoconstrictors and vasodilators. Vasoconstrictors include endothelin, angiotensin II, thromboxane A2, arachidonic acid, prostaglandin H2, thrombin, and nicotine. Vasodilators include nitric oxide, prostacyclin, bradykinin, endoth...