What is the function of red blood cells?

Red blood cells, or erythrocytes, primarily serve the critical function of transporting oxygen from the lungs to the tissues and organs throughout the body. They achieve this via hemoglobin, a protein contained within the cells that binds to oxygen molecules. This feature allows red blood cells to effectively carry oxygen to areas where it is needed for cellular respiration and energy production.

In addition to oxygen transport, red blood cells are also responsible for transporting carbon dioxide, a waste product of metabolism, from the tissues back to the lungs. Once in the lungs, carbon dioxide is expelled from the body during exhalation. This dual function of transporting both oxygen and carbon dioxide is vital for maintaining homeostasis and ensuring that cells receive the oxygen they need while also removing metabolic waste.

While the other options—transporting nutrients, fighting infections, and transporting hormones—are essential functions in the body, these tasks are primarily performed by other components of the circulatory system or the immune system. Nutrients are transported by plasma and various proteins, while white blood cells are responsible for fighting infections. Hormones travel via the bloodstream, often bound to proteins, but are not the role of red blood cells. Thus, the role of red blood cells is distinct and specifically linked to gas