-
The transport of fat, cholesterol and other lipid molecules in the blood is handled by small, shuttle-like substances called lipoproteins. Lipoproteins consist of a lipid, or fatty, core enclosed in a shell containing protein. They can be classified in two primary groups, low-density lipoproteins and high-density lipoproteins.
Function of LDL
Low-density lipoproteins, or LDLs, carry approximately 75 percent of total cholesterol in the blood. Their job is to deliver cholesterol to cell membranes throughout the body for repair.
Function of HDL
The removal of excess cholesterol from the cells and the blood to be eliminated is the responsibility of high-density lipoproteins, or HDLs. Excess cholesterol is transported back to the liver.
Attributes of LDL
LDLs deposit excess cholesterol around the muscle fibers in arteries, forming a fatty plaque that can lead to heart disease. For this reason, it is known as the "bad" cholesterol.
Attributes of HDL
Because it removes excess cholesterol from the blood, thus, reducing the chances for atherosclerotic conditions, HDL is viewed as the "good" cholesterol.
Levels
Lipid profile tests are used to measure total body cholesterol. Desirable levels include LDL levels under 130 mg/DL, HDL levels above 40 mg/DL, and total cholesterol levels under 200 mg/DL.
Source:
Principles of Anatomy and Physiology. Tortora, Gerard and Derrickson, Bryan. 2009
Lipids. In Advanced Human Nutrition. Wildman, Robert and Medeiros, D. 2000
Copyright 2023, Wired Ivy, LLC