What is the role of red blood cells in the circulatory system?

Red blood cells, also known as erythrocytes, play a crucial role in the circulatory system by transporting oxygen from the lungs to various tissues and organs throughout the body. This function is vital for cellular respiration, which is the process by which cells produce energy. Hemoglobin, the protein found in red blood cells, binds to oxygen molecules. As the blood circulates through the lungs, red blood cells pick up oxygen and then deliver it to cells in different parts of the body where it is used for metabolic processes.

In addition to carrying oxygen, red blood cells also help remove some carbon dioxide, a waste product of metabolism, by transporting it back to the lungs, where it is exhaled. However, their primary and most recognized role is in the transport of oxygen. This essential function supports overall health and the efficient functioning of bodily systems, making the correct answer the transport of oxygen.