Analysis of Atherosclerosis
Analysis of Atherosclerosis
Atherosclerosis is the hardening of the innermost portion of the arteries; it is also the most common form of arteriosclerosis. With atherosclerosis, fatty material containing cholesterol or calcium is deposited on the innermost layer of the artery. The result is a narrowing of the inside diameter of the blood vessel, constricting blood flow. . This can progress to the point where the artery becomes so narrow that a blood clot, or thrombus, forms and blocks blood flow to an entire portion of the body. This type of atherosclerosis is considered to happen with the gradual aging of the vessels and plaque build up. Eating foods containing high volumes of cholesterol and saturated fats speeds up this process.
In another form of atherosclerosis, a rough area or ulcer forms in the diseased interior of the artery. Blood clots then tend to develop on this ulcer, break off, and travel further downstream, forming a blockage where the arteries get narrower. This kind of blockage resulting from a clot formed elsewhere in the body is called an embolism. Excessive alcohol use, direct trauma to the vessel, and bacterium tend to cause such lesions. Nicotine contained in tobacco, also tends to enhance platelet aggregation, which may lead to thrombotic (blood clot) events.
Irritation to the endothelium causes immune system response. The injured endothelial cells release chemo tactic compounds and growth factors, which transport greater amounts of lipids, particularly LDLs, to the irritated site. LDLs then in turn become oxidized, and attract macrophages. Plaque becomes full of phages that migrate beneath interna, where they are transformed into foam cells, and loose there scavenging ability.
The smooth muscle cells also deposit collagen and elastin fibers, thickening the interna and producing fibrous lesions with a core of dead and dying foam cells called fibrous or atherosclerotic plaques. As the inner portion of the vessel starts to die it is replaced with non-elastin scar tissue, and calcium salts begin to accumulate in the area. The once elastic vessel is now calcified, and scared, disabling its ability to stretch, increasing systemic blood pressure. The narrowed vessels, and increased blood pressure decreases localized blood flow to the area.
As the artery becomes blocked, it can cause a noise very much like water roaring over rocky rapids. Your physician can listen to this noise, or bruit, directly, or can use special amplification systems to hear this noise....