The respiratory takes in oxygen through the lungs. The oxygen is sent into the blood on red blood cells. This is in the circulatory system. The cells use the oxygen for energy. The waste product is carbon dioxide. This is carried on red blood cells to the lungs and breathed out.
The respiratory takes in oxygen through the lungs. The oxygen is sent into the blood on red blood cells. This is in the circulatory system. The cells use the oxygen for energy. The waste product is carbon dioxide. This is carried on red blood cells to the lungs and breathed out.
