Your liver does filter your blood.
The body depends on the liver to perform a number of vital functions , and although there is substantial overlap, they can be divided into three basic categories:
regulation, synthesis, and secretion of many substances important in maintaining the body's normal state
storage of important nutrients such as glycogen (glucose), vitamins, and minerals,
purification, transformation, and clearance of waste products, drugs, and toxins
Lipids. Cholesterol, a type of lipid, is a substance found in cell membranes that helps maintain the physical integrity of cells. The liver synthesizes cholesterol, which is then packaged and distributed to the body to be sued or excreted into bile for removal from the body. Increased cholesterol concentrations in bile may predispose to gallstone formation.
The liver also synthesizes lipoproteins, which are made up of cholesterol, triglycerides (containing fatty acids), phospholipids, and proteins. Lipoproteins circulate in the blood and shuttle cholesterol and fatty acids (an energy source) between the liver and body tissues. Most liver diseases do not significantly affect serum lipid levels, with the exception of cholestatic diseases, which may be associated with increased levels.
Drugs. Nearly all drugs are modified or degraded in the liver. In particular, oral drugs are absorbed by the gut and transported via the portal circulation to the liver. In the liver, drugs may undergo first-pass metabolism, a process in which they are modified, activated, or inactivated before they enter the systemic circulation, or they may be left unchanged.
Toxins. The liver is generally responsible for detoxifying chemical agents and poisons, whether ingested or inhaled. Pre-existing liver disease may inhibit or alter detoxification processes and thus increase the toxic effects of these agents. Additionally, exposure to chemicals or toxins may directly affect the liver, ranging from mild dysfunction to severe and life-threatening damage.
source:
http://janis7hepc.com/Your Liver Functions.htm