What component of blood is primarily responsible for carrying oxygen?

Red blood cells are primarily responsible for carrying oxygen in the blood. These cells contain hemoglobin, a protein that binds to oxygen in the lungs and transports it to tissues and organs throughout the body. The high concentration of hemoglobin within red blood cells allows for efficient oxygen transport, making them crucial for respiratory function and maintaining cellular metabolism.

In contrast, plasma serves as the liquid component of blood, transporting nutrients, hormones, and waste products, but it does not directly carry oxygen. White blood cells are essential for the immune response, playing a key role in defending the body against infections, but they are not involved in oxygen transport. Platelets are primarily associated with blood clotting and hemostasis, helping to prevent bleeding, rather than transporting oxygen. Therefore, the unique structure and function of red blood cells make them the key players in oxygen delivery within the circulatory system.