cellular components of blood involved in oxygen transport and immunity
Blood cells are the cellular components of blood, primarily including red blood cells (RBCs), white blood cells (WBCs), and platelets. Red blood cells are responsible for transporting oxygen from the lungs to the rest of the body and returning carbon dioxide for exhalation. White blood cells are part of the immune system and help defend the body against infections and foreign invaders. Platelets are involved in blood clotting, which helps prevent excessive bleeding when injuries occur.