The transportation of oxygen and carbon dioxide in the blood

The exchange of gases between the atmosphere, blood and cell is called respiration which has several meaning in physiological terms :


1.External respiration (pulmonary). This kind of respiration includes exchange of gases between blood and lungs . Oxygen from the lungs diffuse into the blood and carbon dioxide diffuse out to the lungs from the blood.

2. Internal respiration (tissue). This is a process of exchange of gases in the body tissues. CO2 from the cells of the body is exchanged from the blood for oxygen.

3. Cellular respiration. It is a cellular process where oxygen is utilized as a fuel to release energy. Thus it is the total biochemical process in a cell for release of energy.

In contrast to these physiological processes, there occurs a mechanical process in higher animals called breathing. It enables us to exchange air in and out of our lungs. Also called ventilation.