What is the primary function of red blood cells?

The primary function of red blood cells is to transport oxygen from the lungs to the rest of the body. This process is facilitated by hemoglobin, a protein found in red blood cells that binds to oxygen molecules. Once the red blood cells take up oxygen in the lungs, they circulate through the bloodstream and deliver oxygen to various tissues and organs, which is crucial for cellular respiration and overall metabolism.

While red blood cells play a vital role in the circulatory system, their main purpose revolves around oxygen transport. Other cellular components, such as white blood cells, are responsible for fighting infections, and hormones are primarily produced by glands in the endocrine system, not by red blood cells. Body temperature regulation is managed through various physiological mechanisms, not directly through the function of red blood cells. This makes the choice that identifies the primary function of red blood cells as oxygen transport the most accurate.