What is a key function of red blood cells?

Red blood cells, also known as erythrocytes, play a critical role in the circulatory system by transporting oxygen from the lungs to various tissues throughout the body. They achieve this function primarily through the presence of hemoglobin, a protein that binds to oxygen molecules. When red blood cells pass through the lungs, they pick up oxygen and then deliver it to the cells that require it for metabolic processes, such as energy production.

Additionally, red blood cells also help in transporting some carbon dioxide, a waste product from cells, back to the lungs for exhalation. This dual function of oxygen transport and some degree of carbon dioxide transport is crucial for maintaining homeostasis and ensuring that the body’s tissues receive the necessary oxygen to function effectively.