What organ is responsible for removing bilirubin from plasma proteins?

The liver plays a crucial role in metabolizing and detoxifying various substances in the body, one of which is bilirubin. Bilirubin is a byproduct of the breakdown of hemoglobin in old red blood cells. Once released into the bloodstream, bilirubin is initially bound to plasma proteins to make it water-soluble and is then transported to the liver.

Within the liver, bilirubin undergoes conjugation, where it is converted from an unconjugated (or indirect) form to a conjugated (or direct) form. This modification allows bilirubin to be excreted more easily into bile, which is sent to the gallbladder for storage or directly into the intestine to facilitate the digestion of fats.

The kidneys, on the other hand, primarily filter blood and remove waste products in the form of urine but do not actively process bilirubin. The spleen is involved in the breakdown of red blood cells and the recycling of iron but does not remove bilirubin from plasma proteins. The gallbladder stores bile but does not remove bilirubin from the plasma. Thus, the liver is the primary organ responsible for the removal and metabolism of bilirubin from plasma proteins.