Canadian Society for Medical Laboratory Science (CSMLS) Practice Exam

Which component of blood is primarily responsible for transport of oxygen?

1. White blood cells

2. Platelets

3. Plasma

4. Red blood cells

The correct answer is: Red blood cells

Red blood cells, also known as erythrocytes, are primarily responsible for the transport of oxygen in the bloodstream. They contain a specialized protein called hemoglobin, which has a high affinity for oxygen. This allows red blood cells to effectively pick up oxygen from the lungs and transport it to tissues and organs throughout the body where it is needed for cellular respiration and energy production. In addition to oxygen transport, red blood cells also play a minor role in the transport of carbon dioxide, which is a waste product of metabolism. However, their main function remains the delivery of oxygen, making them the key component of blood in this context. The other components of blood have distinct functions: white blood cells are primarily involved in the immune response, platelets play a critical role in blood clotting, and plasma serves as a liquid medium that carries nutrients, hormones, waste products, and proteins. Each component is essential for overall health, but red blood cells stand out specifically for their role in oxygen transport.