 Dr. O. In this very important video, we're going to walk through the key features in this part of the body dealing with the respiratory system. So we won't cover everything. You'll see an image just like this again when we talk about swallowing with the digestive system. We've already covered a few structures like the tonsils when we talked about your immune system. So we're going to try to really focus in on the structures involved in breathing and respiration. So the first thing obviously we've got the nose, the nose in the mouth or two pathways where atmospheric air can enter our conducting system and get down to the part of our lungs where we actually trade carbon dioxide and oxygen. But big thing here, so the nose, you know, you've got your nose would have nose hairs that would help kind of clear some debris out of what you're breathing. But the key structure I think of inside the nasal cavity, inside the nose there, is going to be, you see on the right hand side the nasal conch, which are going to be these structures, these outcroppings that enter into the nasal cavity. And then you see on the left side you see the nasal meiosis. Those are the actual openings, the tunnels they create. So these nasal conch create these tunnels that creates turbulence inside your nasal cavity. So when you breathe through your nose, the air swirls around inside your nasal cavity. Reason that's important is while this air is swirling, number one, it's being warmed, right? Because your body temperature is warmer than the atmospheric environment, usually almost always. It's being warmed, it's being filtered by nose hair but also mucus, and then it's also being humidified by the mucus and the moisture that's inside of your nose. So when you breathe through your air, just remember your nose, sorry, the turbulence created by these nasal conch, as it swirls through these nasal meiosis, is what filters, warms, and humidifies your air. It's preparing it to be used. You can breathe through your mouth, but if you do, like especially in the winter, that air is usually cold and dry and may have particulates in it and it is going to be harder on you. This is why a lot of people develop exercise induced asthma or other things when they're, especially in the cold, when they're using air that is irritating to the respiratory system. So those are the key features I see up top there. Obviously your sinuses, sinuses play a role in sound production. They certainly have immune roles, especially if they get full of pathogens, but sinuses are primarily there to decrease the weight of your skull bone, but then also play a role with, with how you sound, which is why if your sinuses are all plugged up, it can change sound production. We covered the meiosis. Again, the tonsils, there's a whole separate video on the tonsils. You can see them all here, so I won't go through them again. Here on the left-hand side, we see the opening of the auditory tube. So you've maybe never heard that term, but most people have heard of the eustachian tube. So that's the opening there in the pharynx for this tube here. Your eustachian tube or auditory tube is the tube that connects your middle ear to the, to the back of your throat. And it's there to equalize the pressure that's, that's inside your middle ear. If this gets all plugged up, that can certainly be problems. This is the main reason why children have a lot more middle ear infections than adults, because when you're a child, the eustachian tube, the auditory tube is short and pretty horizontal. As we grow, it becomes more vertical and longer, so it's less likely to get plugged up. So a lot of times ear infections are not even infections, just inflammation or something plugging up this tube leads to a build of a pressure in the ear. All right, so that's the opening there of the audio tube. We'll cover the pharynx, the three parts of the pharynx in a separate video, the nasopharynx, oropharynx and laryngeal pharynx. We'll come back to that. Same thing with the vestibular folds and the vocal cords there in the larynx. We have a separate video for that. We'll cover the esophagus when we talk about the digestive system. Over here on the right side, we already talked about the nostril and the nose. You'll most often see the nostrils, the opening to the nose itself called the external nares. And then on the inside, where the nasal cavity ends and the pharynx begins, that would be called the internal nares. Not a huge deal, but just in case you see those terms. Hard versus soft palate. So the hard palate is made of most of it's made up of the maxillary bone, but you also have the palatine bone there at the end. The soft palate plays a critical role in swallowing. You see they're the end of the soft palate. You have the uvula, I always call it the barf button, but that's the structure that lifts up when you swallow to make sure things don't exit your nasal cavity. The epiglottis, its job is going to also be during swallowing. So we'll cover that more in a couple of chapters, but it's going to close the glottis, the opening to your trachea when you swallow. So food doesn't go down the wrong pipe. Okay. Everything else in here is going to be covered in other videos, but I really wanted to focus on that nasal cavity there. Just a couple more things. Let me go to, so here you see that the tissue, the cells that line the huge majority of your respiratory tract are going to be pseudo stratified, ciliated, columnar epithelium. Now, I don't really care much about the pseudo stratified part, just means that they look stratified, but they're not, but the ciliated part is going to be very important. And you also see in this image, we have goblet cells. Hopefully remember from earlier chapters about the immune system that goblet cells produce mucus. So the lining of your respiratory tract is going to have a lot of mucus, which is going to help warm and humidify air, but also trap debris and pathogens. That's its primary job. And the ciliated cells, let me show you a good look at some of these tufts of ciliated cells. The cilia, their job is going to be to beat to carry this mucus full of pathogens and debris, carry it up out of your lower respiratory system so you can expel it. You can swallow it or spit it out. So that's just part of the anatomy of this system is constantly producing mucus to capture things and then constantly carrying it away with these ciliated cells. Okay, so that's the nasal cavity and then introduction of some of the other structures around the respiratory system. I hope this helps. Have a wonderful day. Be blessed.