**1. Blood Lipid Absorption and Transport:**
– Short- and medium-chain fatty acids are absorbed directly into the blood via intestine capillaries.
– Long-chain fatty acids are transported as chylomicrons through the lymphatic system.
– Cholesterol is packed into chylomicrons for delivery to the liver.
– Chylomicrons are transported to the bloodstream through the lymphatic system.
– Chylomicrons are taken up by liver hepatocytes.
**2. Cellular Uptake and Secretion of Lipids:**
– Fatty acids are taken up by liver cells, adipocytes, and muscle cells after a meal.
– Insulin stimulates the uptake of fatty acids in cells.
– Fatty acids taken up by the liver are converted into VLDL and secreted into the blood.
– Adipocytes release stored fatty acids into the blood when the concentration decreases.
– Cholesterol is synthesized in response to low blood cholesterol by cells in the liver and intestines.
**3. Lipoprotein and Cholesterol Transport:**
– Cholesterol fate in the blood is determined by lipoproteins.
– Cholesterol is transported in lipoproteins in the bloodstream.
– LDL particles can be categorized as large and buoyant or small and dense.
– Cholesterol circulates in the blood in low-density lipoproteins.
– Cholesterol is taken into cells by LDL receptor-mediated endocytosis.
**4. Lipid-Related Medical Conditions:**
– Hyperlipidemia is the presence of elevated or abnormal levels of lipids and/or lipoproteins in the blood.
– Hypercholesterolemia is high cholesterol levels in the blood.
– Hyperlipoproteinemia is elevated levels of lipoproteins.
– High cholesterol levels are associated with atherosclerosis and cardiovascular disease.
– Dyslipidaemia refers to abnormal levels of lipids in the blood, such as high cholesterol or triglycerides.
**5. Lipid Research and Management:**
– Lipid Hypothesis explains the relationship between blood lipids and heart disease.
– National Cholesterol Education Program provides guidelines for managing cholesterol levels.
– Seasonal Variation in Cholesterol Levels impacts lipid metabolism and treatment strategies.
– Understanding dyslipidaemia as a risk factor for cardiovascular diseases.
– References from scientific journals like Molecular Cell Biology and Lancet contribute to evidence-based lipid management.
This section needs more reliable medical references for verification or relies too heavily on primary sources. (August 2023) |  |
Blood lipids (or blood fats) are lipids in the blood, either free or bound to other molecules. They are mostly transported in a phospholipid capsule, and the type of protein embedded in this outer shell determines the fate of the particle and its influence on metabolism. Examples of these lipids include cholesterol and triglycerides. The concentration of blood lipids depends on intake and excretion from the intestine, and uptake and secretion from cells. Hyperlipidemia is the presence of elevated or abnormal levels of lipids and/or lipoproteins in the blood, and is a major risk factor for cardiovascular disease.