And if we take the sum of the inspiratory capacity and the functional residual capacity, we also get the total lung capacity. Now, the final concept that I'd like to briefly discuss that relates to lung volume and capacity and breathing is known as the anatomic death space. So, every single time we take a breath let's suppose we're taking a resting breath. We inhale. We exchange 500 air every single time we breathe. Now, only a portion of this air actually ends up in the alveoli of the lungs, where gas exchange actually takes place.