Now, we can also use the halding effect to basically describe how the alveoli of the lungs are able to absorb more carbon dioxide from the blood plasma. So the Held in effect can also be used to explain how oxygen concentration affects carbon dioxide unloading into the alveoli of the lung. So let's take a look at the following diagram. So, as always, we have the red blood cell, and this is the alveolus of our lung. Now, what's happening inside our lungs? Well, inside our lungs, the oxygen is moving down its concentration gradient from the alveolus and into the red blood cell.