For this example, we need to remember the definitions that we just learned, and so we need to match the definitions to these four words: respiration, inspiration, expiration. Do you remember which one of those words refers to the movement of air out of the lungs? Well, that is going to be expiration. Expiration is the movement of air out of your lungs. The next one we have here is the exchange of gases with the blood. Do you remember which one that is? Alright, the exchange of gases with the blood. This is one that, for me, is always hard to remember that this is what's going on there, but that is respiration. Respiration, the movement of that carbon dioxide and oxygen specifically in and out of the blood. So, I'm going to put a on the line for number 2 there.

Next, we have movement of air into the lungs. Alright, which one of those words is the movement of air into the lungs? Well, that was inspiration. Inspiration right there, b. So I'm going to put b on this line here for number 3. And then finally, we have movement of air into and out of the lungs. That movement in and out together. What do we call that? Well, there's only one option left, but let's make sure it makes sense. Ventilation. That is what we call it. We ventilate our lungs by moving air in and out, so I'm going to put d here on the line for number 4. Alright. Those four words we're going to be using a lot going forward, so make sure you have them straight in your head.