السلام عليكم ورحمة الله وبركاتة

شباب انا ابغي بحث لمادة الإنكليزي لأني دورة وله حصلة فأرجوا منكم التكرم بمساعدتي ...,,,,,



والي بساعدني يحصل ليي واحد من هالمواضيع إلي مخليين:

1-Cholestrol (كولسترول)

2-Healthy Food (الطعام الصحي)

3-Keeping Filt (كيف تكون صحي)

أرجوا منكم مساعدتي

ونسألكم الدعاء

وعليكم السلام ورحمة الله وبركاته ..


((( كوليسترول )))



Cholesterol, a complex alcohol constituent of all animal fats and oils. It can be activated to form vitamin D. Cholesterol is one of a group of compounds known as sterols and is related to such other sterols as the sex hormones and the hormones of the adrenal cortex.

A close relationship exists among levels of blood cholesterol in the body, those of other fats or lipids, and the development of atherosclerosis . In this disorder, plaques containing cholesterol are deposited on the walls of arteries, particularly those of small and medium size, reducing their inside diameter and the flow of blood. Clotting of blood, such as may occur in the coronary arteries to cause a heart attack, is most likely to develop at places where arterial walls are roughened by such plaques.

Although many foods, particularly dairy products and meat fat, contain cholesterol, the body also synthesizes this sterol from cholesterol-free substances. Nevertheless, investigation indicates that a cholesterol-rich diet causes abnormally high levels of cholesterol and the related fats and lipids in the blood. Evidence strongly indicates that people with such high levels are more likely to develop atherosclerosis and heart attacks than those with lower levels. Also significant is the fact that scientists have identified two forms of cholesterol-carrying proteins in the blood, called high-density and low-density lipoproteins. The low-density form is thought to promote atherosclerosis, whereas the high-density component may retard it. In 1984, the United States National Heart, Lung and Blood Institute reported results of a study indicating that high levels of low-density lipoproteins also increased the risk of heart attacks and heart disease.

Persons who have abnormally high levels of cholesterol—especially low-density cholesterol—on a congenital basis can reduce their risk of heart attack by lowering their blood cholesterol. This is done by following a diet low in cholesterol and saturated fats, getting sufficient exercise, and using certain drugs. In 1987, lovastatin, one of a class of drugs that inhibit cholesterol synthesis, was approved for sale in the United States. Many similar drugs are now available. See Nutrition, Human.

Cholesterol and its derivatives are secreted through the oil glands of the skin to act as a lubricant and protective covering for the hair and skin. Lanolin, a grease extracted from raw sheep wool and composed largely of cholesterol esters, has a variety of commercial uses in lubricants, leather preservatives, ointments, and cosmetics.