It is because they bind to Hemoglobin. Hemoglobin is contained in the red blood cells which efficiently carries oxygen from the lungs to all the tissues in the body. It also helps in the transportation of carbon dioxide and hydrogen ions back to the lungs.
We are composed of one skeleton that can be divided into two major regions, the axial and appendicular skeleton. The axial skeleton makes up our central axis and consists of the following bones: skull, vertebrae, ribs and sternum. The appendicular skeleton consists of the limbs and girdles.
