What are the processes involved in the exchange of gases?

Well,: There are two places where gases are exchanged, one in the lungs an one at tissue levels. In both cases oxygen (o2) and carbon dioxide (co2) are exchanged: in the lungs co2 is given up an exhaled, while o2 is taken in by the red cells and transported everywhere in the body. At tissue level tho opposite is happening:o2 is given up and co2 is carried to the lungs.