Final answer:
Macrophages are the cells responsible for destroying old and damaged red blood cells, primarily in the liver and spleen, as part of the body's natural recycling process to maintain healthy blood composition.
Step-by-step explanation:
Cells called macrophages destroy old red blood cells, primarily in the liver and spleen. Erythrocytes, or red blood cells, have a lifespan of about 120 days in the circulation before they are phagocytized by macrophages. These specialized immune cells are located primarily within the bone marrow, liver, and spleen, where they engulf and breakdown the worn-out erythrocytes. The components of the degraded erythrocytes' hemoglobin are then further processed. This process is essential for maintaining the balance and health of the bloodstream and for recycling the materials contained in the blood cells. Red blood cells are crucial as they carry oxygen throughout the body and are formed from stem cells in the bone marrow.