Which organ is primarily responsible for recycling iron from old red blood cells?

The spleen plays a critical role in the recycling of iron from old red blood cells. This organ acts as a filter for the blood, removing aged and damaged erythrocytes. When red blood cells reach the end of their life span, they are phagocytized by macrophages in the spleen, where hemoglobin is broken down. This process releases heme, which then undergoes further breakdown to release iron. The iron can then be stored for future use or transported back to the bone marrow for the production of new red blood cells.

While other organs, such as the liver, are involved in the overall metabolism and storage of iron, they do not primarily handle the recycling of iron from old red blood cells. The kidneys focus on filtering blood and excreting waste but do not play a significant role in iron recycling. Bone marrow is crucial for the production of new red blood cells but is not involved in the recycling process of iron from older cells. This distinct function of the spleen underscores its importance in maintaining iron homeostasis and supporting hematopoiesis.