Which component of blood is primarily responsible for oxygen transport?

Red blood cells are primarily responsible for oxygen transport in the bloodstream. These cells contain a protein called hemoglobin, which binds to oxygen molecules in the lungs and carries them to tissues throughout the body. Hemoglobin's structure allows for efficient uptake of oxygen as blood passes through the pulmonary circulation and delivers it to various organs and cells where it is utilized for cellular respiration.

In contrast, white blood cells are primarily part of the immune system and help defend the body against infections, while platelets are essential for blood clotting and wound healing. Plasma is the liquid component of blood that carries cells, nutrients, hormones, and waste products, but it does not play a direct role in oxygen transport. Thus, the designation of red blood cells as the key component for transporting oxygen is an essential aspect of understanding human physiology.