Red blood cells are broken down in the reticuloendothelial system, primarily the spleen. The dead cells inside the spleen are converted to bilirubin upon removal of iron. This process accounts for about 80% of the bilirubin formed every day inside a human body. The bilirubin is transferred to liver in the form of indirect or unconjugated bilirubin. Conjugated bilirubin is excreted via the biliary system into the intestine, where ... Read more