Which organ is primarily involved in hematopoiesis and destruction of aged red blood cells?

• A. Lymph Node
• B. Tonsil
• C. Thymus
• D. Spleen

Answer: (D)

The spleen is specialized in filtering blood and recycling old red blood cells. Its red pulp contains macrophages that phagocytose senescent erythrocytes and recycle iron from hemoglobin, while the spleen can also support hematopoiesis during development or under stress (extramedullary hematopoiesis). In adults, bone marrow is the main site of hematopoiesis, but among the options given, the spleen is the organ most linked to clearing aged red blood cells. Lymph nodes, tonsils, and the thymus are primarily involved in immune responses and lymphocyte maturation, not in the destruction of aged RBCs.