1. Blood lipids are the general name of neutral fats (triglycerides) and lipids (phospholipids, glycolipids, sterols and steroids) in plasma, which are widely found in human bodies. They are essential substances for the basic metabolism of living cells. Generally speaking, the main components of blood lipids are triglycerides and cholesterol, among which triglycerides participate in energy metabolism in the human body, while cholesterol is mainly used to synthesize plasma membrane, steroid hormones and bile acids.
Second, the lipids contained in plasma are collectively referred to as blood lipids. Although the plasma lipid content only accounts for a small part of the whole body lipid, both exogenous and endogenous lipid substances need to move between tissues through blood. Therefore, the content of blood lipid can reflect the situation of lipid metabolism in the body.
Third, after eating a high-fat diet, the plasma lipid content increases greatly, but this is temporary, and usually it can gradually become normal after 3 to 6 hours. When testing blood lipids, blood samples are often taken after meals 12 ~ 14 hours, so as to reflect the true situation of blood lipid level more reliably. Because the increase of plasma cholesterol and triglyceride levels is related to the occurrence of atherosclerosis, these two items have become the key items in blood lipid measurement.
4. All blood lipids combine with protein to form lipoproteins. The basic structure of lipoprotein is composed of triglycerides with different contents, surrounded by a layer of phospholipids, cholesterol and protein molecules.
Five, the source of blood lipids in the human body has two ways, namely endogenous and exogenous. Endogenous blood lipid refers to the blood lipid components synthesized by tissues and cells such as liver and fat. Exogenous blood lipid refers to the blood lipid components ingested from food. Specifically, endogenous blood lipid refers to a serum lipid substance secreted and synthesized by the human body itself. Endogenous blood lipids first pass through the liver and fat cells, then combine with cells and release into the blood, which can become the energy source of human metabolism and life activities.
6. Compared with endogenous blood lipids, blood lipids that come from the outside and cannot be directly synthesized by the human body are called exogenous blood lipids. Most of these blood lipids are absorbed by the human body from food intake. After food is digested and absorbed by the gastrointestinal tract, lipid substances enter the blood, thus becoming blood lipids.