What is the primary function of red blood cells (RBCs)?

The primary function of red blood cells (RBCs), also known as erythrocytes, is to transport oxygen from the lungs to tissues throughout the body. This is achieved through the molecule hemoglobin found within RBCs, which binds to oxygen in the lungs and releases it in the tissues where it is needed for cellular respiration and energy production. The efficient delivery of oxygen via RBCs is crucial for the functioning of organs and overall metabolism, as oxygen is essential for the survival of cells.

While RBCs play a vital role in oxygen transport, other blood components serve distinct functions. For instance, white blood cells are responsible for protecting the body against infections, platelets are involved in blood clotting, and plasma carries various nutrients, hormones, and waste products. However, these functions do not relate to the primary role of RBCs. Thus, the correct identification of their main function as oxygen carriers underscores the importance of these cells in maintaining the body’s energy and homeostasis.