What is the X in X-mas?
bilirubin bil·i·ru·bin (bĭl'ĭ-rōō'bĭn, bĭl'ĭ-rōō'-)
A red bile pigment derived from the degradation of hemoglobin during the normal and abnormal destruction of red blood cells.
a brownish yellow pigment of bile, secreted by the liver in vertebrates, which gives to solid waste products (feces) their characteristic colour. It is produced in bone marrow cells and in the liver as the end product of red-blood-cell (hemoglobin) breakdown. The amount of bilirubin manufactured relates directly to the quantity of blood cells destroyed. About 0.5 to 2 grams are produced daily. It has no known function and can be toxic to the fetal brain.