Here's why:
* Hemoglobin: Red blood cells contain a protein called hemoglobin. Hemoglobin has a high affinity for oxygen, meaning it readily binds to oxygen in the lungs.
* Oxygen Transport: When red blood cells travel through the body, the hemoglobin releases the oxygen to the tissues that need it.
* Carbon Dioxide Transport: Red blood cells also play a role in carrying carbon dioxide (a waste product of respiration) back to the lungs to be exhaled.
While other cells might contribute indirectly to gas transport (like the cells that line the lungs or the cells that make up blood vessels), it's the red blood cells that are specifically designed for this vital function.
