 Okay, we made it through all the stuff in your head. We made it through all my pharynxes in the back. We made it through the larynx where we make sound and the trachea. And there's only one trachea, my clowns. There's only one. And look, here it is. Here's my trachea, here's my larynx, piece of cake, right? And up here, this is my epiglottis. Everything's good, right? Everything else is contained within the lungs. So look, my trachea. How far down does it go? It goes far. And then it does this amazing thing. It bifurcates. What? Holy bifurcation. Trachea bifurcates into two tubes that look like little tracheas, but they're not. And we're going to talk about them next. They're bronchies, but the bronchi are contained in the lungs. So you could take a lung out and cut it all up. And inside that lung, you're going to have all sorts of structures. And that's where we're going next. Now the lungs are contained in a cavity. What cavity are they in? Dude, take your pick. They're in the thoracic cavity. What other cavity are they in? They're in the plural cavity. So watch and be amazed. So amazing. This whole thing, do you agree? This whole thing is my thoracic cavity. Hey, did we even talk about one of the coolest things ever, which we haven't? Okay, I can't help it. I feel like I'm in physio right now. What is this? Okay, this is separating. Oh my gosh, for real. This right here is separating my thoracic cavity from what? What is inferior to the thoracic cavity? The abdominal cavity. I can start drawing stomachs and livers down here. This is abcav. Superior to all of that is thoracic cav, thoracav. And who is this guy? Who is that masked separator? It's the diaphragm. But don't say the G because it's not pronounced like that. It's just spelled like that. So the diaphragm is actually a skeletal muscle that we will know and be able to identify. And when the skeletal muscle contracts, it actually increases the volume of the thoracic cavity. What else was in the thoracic cavity? What other cavity is possibly in here? The pleural cavity. Okay, now watch. The pleural cavity is just like the peritoneal cavity. But there's no retro pleural. The pleural cavity contains the lungs. Now watch and be gloriously excited. I'm not going to do it that way. I'm going to do it like this so that you can see that we have one piece of pleural like membrane. Look, can you follow me? Can anyone follow me? I mean, what color should I go next? Let's try this pink. Whoa. What did I just do? That pink really blends in with my lung. That's okay because you can see that I'm drawing something different, right? That actually isn't bad. What is this pink thing called? This pink thing that is covering the lung, the organ in the pleural cavity. That's the visceral, yeah? Easy pleura. Dude, how money is anatomy when things make sense? So who's this guy that's lining the pleural cavity which is essentially half of the thoracic cavity? This is the parietal pleura. True story. Now, you want to know something even more amazing? Inside here is the pleural cavity. It is. That's awesome. This space right here is a potential space that is filled with what kind of fluid? Cirrus fluid. And I'm just going to tell you right now that the pressure inside here is low. And I don't want to get too crazy into it, but the fact that inside this space, the intraplural space between the parietal pleura and the visceral pleura, inside that space, it maintains a low pressure zone. And so your lungs stay inflated because your lungs have more pressure in them. That is why your lungs do not collapse. And in fact, if your lung does collapse, it means that you lost this low pressure zone in that space. And then they stick a tube in that space and they suck out all the fluid and all the air and try to reestablish basically a vacuum, a low pressure zone. That's what keeps your lungs inflated. That's crazy talk. That's physio. We'll try not to get too crazy and excited about that. Your lungs are not symmetrical. Why not? Why not? That's so, so lame. Why not? Because your heart, you have to have room for your heart and your heart kind of leans a little bit toward the left. It's actually in the middle of your body but the bigger part goes to the left side. That is my left side. And so your left lung has two lobes. Again, containing all the rest of the structures we're going to talk about, your right lung has three lobes. This would be a phenomenal question. If I, like, could find lungs and they had one had two lobes and one had three lobes, you could tell me did it come from the right side or the left side of the body? Lungs, I feel very satisfied with this. Do you? The whole serious membrane thing is making sense, isn't it? Those are so smart.