What is the primary function of red blood cells?

The primary function of red blood cells is to transport oxygen to body tissues. This role is primarily accomplished through a protein called hemoglobin, which is contained within the red blood cells. Hemoglobin has a high affinity for oxygen, allowing red blood cells to pick up oxygen in the lungs and release it in the tissues where it is needed for cellular metabolism. This oxygen transport is essential for maintaining the health and function of all body cells, as oxygen is critical for the production of energy.

Other functions, such as aiding in digestion, fighting infections, or producing hormones, are carried out by different types of cells and systems within the body. For instance, the digestive process is facilitated by various enzymes and organs, immune responses are managed by white blood cells, and hormone production occurs predominantly in glands such as the thyroid or pancreas. Thus, the specific and vital role of red blood cells is centered on oxygen transport, highlighting their importance in respiratory and circulatory physiology.