What is the primary function of red blood cells?

The primary function of red blood cells is to carry oxygen from the lungs to the tissues throughout the body. They achieve this through a protein called hemoglobin, which binds to oxygen molecules. Once the oxygen is delivered to the body's cells, red blood cells also assist in transporting carbon dioxide, a waste product of metabolism, back to the lungs for exhalation. This vital role in oxygen transport is essential for cellular respiration and overall metabolic processes, making the effective functioning of red blood cells crucial for sustaining life.

In contrast, while fighting infections is primarily the role of white blood cells, digestion is facilitated by enzymes and specialized cells in the digestive system, and blood clotting involves platelets and clotting factors rather than red blood cells.