Gases exchange...... Thats my answer
Aside from the Gas Exchange (as mentioned by the Kristina in the answer below) the physiological aspect of respiration is the transportation of oxygen to our cells and the exhaustion of Carbon Dioxide from our system. When respiration happens, our diaphragm compresses and our chest expands to help our lungs suck in the air. When this happens, our lungs filter the air and get the oxygen that our body needs through air sacs. From the air sacs, the oxygen then go to the capillaries and loads into the red blood cells which are circulated in our body.