The liver is important in the detoxification of chemicals absorbed into the bloodstream by other routes such as the skin and lungs. The liver receives blood from two sources, the hepatic artery and the portal vein. The liver can be organized into subunits based upon its anatomy or its functions. The functional structural subunit of the liver is the liver acinus. One function of the liver that is especially important in hepatotoxicity and detoxification is the synthesis of bile. Fatty liver is an excess accumulation of lipid in the parenchymal tissue. Microscopically, the hepatocytes in fatty liver appear to be filled with numerous lipid droplets that push aside other cellular components. Hepatocyte death is the end-result of excessive or prolonged exposure to hepatotoxic agents. It is often preceded by fatty liver. The liver is the principle organ for the detoxification of ingested, inhaled, or absorbed toxic chemicals.