Air moves from the alveoli to the blood after being inhaled into the lungs. The alveoli get oxygen to the blood and then the carbon dioxide moves from the blood to the alveoli, so it can be released when you exhale. :)
I hope I didn't make that sound confusing. xD
A. Nervous, regulation
It's your body's way of regulating to maintain its homeostasis using the nervous system as the control center
Oxygen cycle The cycling of oxygen between the biotic and abiotic components of the environment (see biogeochemical cycle). ... In the process of respiration oxygen is taken in by living organisms and released into the atmosphere, combined with carbon, in the form of carbon dioxide.