What is the function of red blood cells?

Red blood cells (RBCs), or erythrocytes, transport oxygen from the lungs to tissues and carry carbon dioxide back to the lungs for exhalation. They contain haemoglobin, a protein that binds to oxygen, giving RBCs their red colour. Produced in the bone marrow, red blood cells have a lifespan of about 120 days. Their unique biconcave shape increases surface area, allowing efficient gas exchange. Proper red blood cell function is essential for delivering oxygen throughout the body and maintaining overall health.