arteriosclerosis

The name given a group of degenerative diseases of arteries characterized by thickening and hardening of their walls. The group includes three types of lesions: (1) atherosclerosis involves the aorta and its major branches; (2) medial sclerosis involves the muscular arteries of the legs; and (3) arteriolosclerosis involves the small branches of the arterial tree, called the arterioles.

Atherosclerosis is by far the most common and important form of arteriosclerosis, and the two terms are often used interchangeably. Atherosclerosis has global distribution and occurs in virtually epidemic proportions in the Western industrialized nations. Factors associated with the high incidence and severity of atheromas (anatomic lesions of atherosclerosis) include a high total caloric intake, high fat intake, sedentary living, aggressive personality, emotional stress, and cigarette smoking. Hypertension (high blood pressure) does not induce arteriosclerosis, but it augments its development and accelerates the progress of the disease if it is present. The excessive incidence of myocardial infarction (heart attack) in cigarette smokers has been clearly documented. High blood lipid levels especially of cholesterol and triglycerides are also associated with higher incidence. The strong supposition thus arose that environmental and nutritional factors are of prime etiologic importance in the development of the disease, although the specific cause has not been identified. See also Heart disorders; Hypertension.

Atheromas begin within the lining layer of the aorta (intima) or its branches and subsequently extend into the middle layer (media) of these vessels. The basic lesion has been shown to be a focal overgrowth of the smooth muscle cells of these layers, possibly following from a mutation. The cells subsequently degenerate, producing an accumulation of lipids in their cytoplasm, then necrosis, and finally calcification and scarification. As these lesions enlarge in the intima, the overlying endothelial cells may become disrupted, and fibrin clots are deposited on the surface. The lumen of the vessel is diminished in diameter (stenosis) by both the atheromatous plaque and the overlying clot. The occurrence of successive layers of clots and enlarging plaque produces narrowing of the lumen. If the process involves all layers of the arterial wall, it may weaken the wall, and an aneurysm may result.

When the atherosclerotic process occurs in the smaller branches of the aorta, complete occlusion may occur. If the process takes place in the vessels supplying blood to the heart muscle (coronary arteries), the blood supply may be restricted or stopped completely, producing a myocardial infarction. If the process involves the arteries supplying the brain, hemorrhage and stroke may occur. If arteries leading to the legs, arms, or internal organs are occluded, gangrene may result. Because of these sequelae, atherosclerosis assumes awesome importance as the major cause of death in the United States. See also Hemorrhage.

Although the vast majority of cases of atherosclerosis appear to be principally caused by environmental factors, there are some specific genetic defects associated with the genesis of the process. Individuals with primary diabetes mellitus develop severe arteriosclerosis at an earlier age than nondiabetic individuals do. Familial hypercholesterolemia, homocystinuria, and hypothyroidism are other examples of metabolic defects associated with arteriosclerosis. See also Diabetes.

Medial sclerosis is an uncommon type of arteriosclerotic lesion, affecting arteries of the arms, legs, and genital tracts of both sexes. The disorder is characterized by ringlike calcifications within the media (middle layer) of affected vessels. The endothelial lining of the vessel is not altered, and occlusion of the vessel seldom occurs.

Arteriolosclerosis is an increased generalized thickening of the walls of arterioles related to hypertension. The change is often most prominent in the kidneys, although other internal organs may be similarly affected. Individuals with diabetes mellitus have an increased incidence of the lesion. See also Circulation disorders.

Thickening and calcification of the arterial walls, leading to loss of elasticity, occurring with ageing and especially in hypertension. See also atheroma; atherosclerosis.

A general term that is applied to a number of problems associated with a thickening and hardening of an arterial wall, and reduced elasticity of blood vessels. Arteriosclerosis is associated with high blood pressure and heart disease. It is more common among people who are inactive and have unbalanced diets, high in fat. The risk is reduced by taking regular, vigorous aerobic exercise.

Dansk (Danish)
n. - arteriosklerose, åreforkalkning

Nederlands (Dutch)
aderverkalking

Français (French)
n. - (Méd) artériosclérose

Deutsch (German)
n. - (med.) Arteriosklerose, Arterienverkalkung

Ελληνική (Greek)
n. - (παθολ., μτφ.) αρτηριοσκλήρωση

Italiano (Italian)
arteriosclerosi

Português (Portuguese)
n. - arteriosclerose (f) (Med.)

Русский (Russian)
артериосклероз

Español (Spanish)
n. - arteriosclerosis

Svenska (Swedish)
n. - åderförkalkning

中文（简体）(Chinese (Simplified))
动脉硬化

中文（繁體）(Chinese (Traditional))
n. - 動脈硬化

한국어 (Korean)
n. - 동맥 경화[증]

日本語 (Japanese)
n. - 動脈硬化症, 動脈硬化

العربيه (Arabic)
‏(الاسم) تصلب الشرايين‏

עברית (Hebrew)
n. - ‮טרשת עורקים‬

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