Final answer:
The circulatory system, particularly the erythrocytes or red blood cells containing hemoglobin, is responsible for transporting oxygen throughout the body and exchanging gases like carbon dioxide and oxygen between the lungs and tissues.
Step-by-step explanation:
Your circulatory system is responsible for transporting oxygen to tissues in the body that need it. The majority of oxygen is transported by erythrocytes, also known as red blood cells, which contain the metalloprotein hemoglobin. Hemoglobin binds oxygen molecules, with each molecule capable of carrying up to four molecules of oxygen. These erythrocytes pick up oxygen in the lungs, and via the bloodstream, this oxygen is distributed throughout the body.
Oxygen is essential for metabolic reactions that occur in body cells, and the byproduct of these reactions, carbon dioxide, also needs to be transported away from the cells. The circulatory system, therefore, has a critical role in the exchange of gases, such as oxygen and carbon dioxide, between the lungs and other tissues of the body, for maintaining the body's metabolic functions.