A yellow-brown pigment containing iron, derived mainly from hemoglobin and produced through hemolysis
Hemosiderin is formed inside of macrophages, especially after hemorrhage. The red blood cells that escape from ruptured blood vessels disintegrate, releasing hemoglobin. The hemoglobin molecules are engulfed by macrophages to be broken down into hemosiderin and porphyrin.
Word origin: Greek haima + sidero (iron)