The red blood cells/RBC’s/erythrocytes are responsible for supplying oxygen from the lungs to different body parts. After a short life span of 120 days, the old/weak RBC’s are destroyed by the spleen. RBC’s do not divide or self repair but are formed again by the process of erythropoiesis (erythro-red and poiesis-formation) in the bone marrow.
REFERENCE:
The Average life span of a circulating red blood cell is 100 to 120 days, and after it, the macrophages engulf it.