cellular respiration

What is the big picture overview of how gases are exchanged, generated, and moved through our body?

We first breathe in  oxygen (O2)

 which makes it way to our alveoli

 through the airways called bronchi

 . This gas then enters the blood

 and is picked up by red blood cells.

Red blood cells deliver the gas to the tissues.

The gas is used up in a process called cellular respiration which is necessary to make ATP (the usable energy of a cell).

 In the process, carbon dioxide (CO2) is generated as a waste product. 

This waste product is picked up by red blood cells from the tissues

 and delivered to the alevoli

 where it is eventually expired out of the body.