Cholesterol is a soft, waxy substance found among the lipids (fats) in the bloodstream and in all your body's cells. It's an important part of a healthy body because it's used to form cell membranes, some hormones and is needed for other functions. But a high level of cholesterol in the blood ?hypercholesterolemia ?is a major risk factor for coronary heart disease, which leads to heart attack.
Cholesterol and other fats can't dissolve in the blood. They have to be transported to and from the cells by special carriers called lipoproteins. There are several kinds, but the ones to focus on are low-density lipoprotein (LDL) and high-density lipoprotein (HDL).
from.... www.americanheart.org/presenter.jhtml?identifier=4488 - 45k -
Cholesterol is a sterol (a combination steroid and alcohol) and a lipid found in the cell membranes of all body tissues, and transported in the blood plasma of all animals. Trace amounts of cholesterol are also found in plant membranes.
The name originates from the Greek chole- (bile) and stereos (solid), and the chemical suffix -ol for an alcohol, as researchers first identified cholesterol in solid form in gallstones in 1784.
Cholesterol is not necessarily dietary in origin; it is synthesized internally by the body from unburned food metabolites. Its level in blood can be raised beyond natural levels by eating raised food amounts, especially with cholesterol-containing foods. Cholesterol is more abundant in tissues which either synthesize more or have more abundant densely-packed membranes, for example, the liver, spinal cord, brain, and atheromata (arterial plaques). Cholesterol plays a central role in many biochemical processes, but is best known for the association of cardiovascular disease with various lipoprotein cholesterol transport patterns and high levels of cholesterol in the blood. Cholesterol is insoluble in blood, but is transported in the circulatory system bound to one of the varieties of lipoprotein, spherical particles which have an exterior composed mainly of water-soluble proteins.
In recent years, the somewhat imprecise term "bad cholesterol" has been used to refer to LDL (low-density lipoprotein) which, according to the lipid hypothesis, is thought to have harmful actions, and "good cholesterol" to refer to HDL (high-density lipoprotein), thought to have beneficial actions.
from. wikipedia
Cholesterol is a fatty substance (a lipid) that is an important part of the outer lining (membrane) of cells in the body of animals. Cholesterol is also found in the blood circulation of humans. The cholesterol in a person's blood originates from two major sources; dietary intake and liver production. Dietary cholesterol comes mainly from meat, poultry, fish, and dairy products. Organ meats, such as liver, are especially high in cholesterol content, while foods of plant origin contain no cholesterol. After a meal, cholesterol is absorbed by the intestines into the blood circulation and is then packaged inside a protein coat. This cholesterol-protein coat complex is called a chylomicron.
The liver is capable of removing cholesterol from the blood circulation as well as manufacturing cholesterol and secreting cholesterol into the blood circulation. After a meal, the liver removes chylomicrons from the blood circulation. In between meals, the liver manufactures and secretes cholesterol back into the blood circulation.
from. medicine net
Links to other sites on the Web
Who Am We?
To. President No Moo Hyun
Who Am I?
Term Paper
Chenua Achebe
Rest of my essays