What happens to aging or damaged erythrocytes?

• A. Phagocytized in spleen and liver by macrophages
• B. Excreted in urine
• C. Converted into leukocytes
• D. Stored in bone marrow

Answer: (A)

When red blood cells age, they are targeted for removal by the body's phagocytic system. Macrophages in the spleen (especially the red pulp) and to some extent in the liver engulf and digest these damaged cells. This process recycles components: iron is reclaimed and reused for new hemoglobin synthesis, while the heme is converted to bilirubin and processed by the liver for excretion in bile. This is how the body safely clears old erythrocytes without dumping them into urine or turning them into white blood cells, and without storing them in the bone marrow.