What is the primary role of red blood cells?

The primary role of red blood cells, also known as erythrocytes, is to transport oxygen from the lungs to the body's tissues and organs. These cells contain hemoglobin, a specialized protein that binds to oxygen molecules. When red blood cells pass through the lungs, oxygen diffuses into them, where it binds to the hemoglobin. As the cells circulate through the bloodstream, they release this oxygen to the cells of the body, enabling them to perform essential metabolic functions.

While red blood cells contribute to carbon dioxide transport back to the lungs for exhalation, their main function is predominantly oxygen transport. The roles of fighting infections and forming blood clots are primarily functions of other blood components, such as white blood cells and platelets, respectively.