Hello biology class welcome to lesson two of the respiratory system titled the mouth fairings and larynx. This is all stuff we talked about a little bit in the digestive system unit but we're gonna talk about it in a little bit of a different context. You can see the key points mouth cleft palate fairings and larynx. We all kind of self-explanatory and things that we've talked about before. So let's jump right in and talk about it in a breathing context. So nose to mouth. Your nose and your mouth are connected by the nasal fairings and oro fairings. It is at the back of your throat. That is why you can breathe through your nose or your mouth. They go to the same place. There is that connection. If you check out this chain video you can see a person put a necklace chain essentially through their nose down their throat and then you can grab it out their mouth and you can see that there's connection. You can also put your headphones up your nose and open your mouth and it creates a very good speaker if you know a group of people are wanting to listen to music. So check out those videos. They kind of prove in different ways that your nose and your mouth are connected and that they both lead at the same place which is your throat. So your mouth plays an important role in eating, drinking, and speaking. Speaking is a respiratory system role. And mouth breathing refers to the act of breathing through the mouth. If there is an obstruction to breathing through the nose. The nose is the designated breathing organ for the human body but sometimes the mouth is easier to breathe through if we are performing physical activity or if we are scared or if you know there is a blockage to our upper to our nose area. So mouth breathing is an option but it's not recommended for regular life as you miss out on a lot of the benefits that your nose and your sinus give which is the moistening filtering and warming of air as it goes into the lungs. It is very important to do that so that you do not damage them in the cold especially our cold climates can cause a lot of damage to lungs when you're only breathing through your mouth and if you're breathing very quickly. The cleft palate, something we've talked about a little bit before, it is a passage that connects the mouth and the nasal cavity or the nasal cavity and the oral cavity. It is often going through the hard palate sometimes into the soft palate you can have a double cleft you can have a partial cleft and this can sometimes cause people to have a higher voice as there is no seal here and again it's easier easily repaired with surgery at an early age. The pharynx is your throat it is a cavity that connects the oral cavity and the nasal passage to the lower respiratory system. The pharynx is part of the digestive system and part of the conducting zone of the respiratory system so the conducting zone is essentially the air collecting portions of your mouth and your nose into your throat so that is the conducting zone the part that kind of funnels air into your lungs and this pharynx also filters, warms and moisons the air as it brings it into your lungs so again a very important function. The pharynx as we know is conventionally divided into three sections there's the nasal pharynx or the nose part of the pharynx the oral pharynx or the mouth part of the pharynx and the laryngeal pharynx or the larynx part of the pharynx that is essentially near your voice box and again the function is connect the nose and the mouth to the lower respiratory system and to allow us to eat and breathe at the same time. So we have the three types of pharynx the oral pharynx and the nasal pharynx are the upper and middle parts of the throat that direct air downwards into the laryngeal pharynx and the lower respiratory system. We have yes a picture here this would be the nasal pharynx we have the oral pharynx and then the laryngeal pharynx would be this portion and the larynx is right here it is the front tube the esophagus is the back tube and the tragi or the windpipe is the front tube and we have our epiglottis here that does the folding down to block the windpipe when we're eating food. So again we have the epiglottis is a leaf shaped flap in the throat that prevents food from entering the windpipe and the lungs it stands open during breathing which allows air into the larynx it is also open when you're speaking which is why speaking and eating can be very difficult to do you need to have that epiglottis open and closed at the same time. Epiglottis epiglottis is an inflammation of the epiglottis that can result from an infection or other causes such as physical trauma. A severe a severely swollen epiglottis can block the airway causing breathing difficulties which can be fatal. Check out a couple of these videos which show exactly what the epiglottis is and does if you need that refresher from the digestion unit. The larynx is what we call the voice box. It is the organ at the top of the neck the top of the throat right here in males you can often feel the atom's apple and if you press hard enough you can kind of feel the hard cartilage as it expands. That larger portion is the housing of your vocal cords so it is the organ at the top of the neck involved in breathing and producing sound it is also protecting the top of the trachea. So the larynx houses the vocal cords and manipulates pitch and volume which is essential for fination. So essentially it manipulates how high or low your voice goes and the volume of it how loud it is which is essential for speaking but fination is speaking. So we can manipulate in different ways the pitch and volume of our voices using microphones or using different if you use helium you can make it go higher which makes your voice sound different. So here's a picture of your larynx this is a camera that's gone into the throat just past the epiglottis there is cartilage that is hard that protects it so that you can't like push it in easily but these are the vocal cords and they'll tighten up or they'll widen and loosen depending on how high or low you want your voice to go. So check out these videos, check out these videos. They're different videos of people making their voice go up and down it's very important that you realize or know these different gases that cause these different things helium is pretty common but sulfur hexafluoride and xenon are both a little bit less common probably haven't seen them before. What I'd like you to do now is your job you go to this website again and do some research about how the larynx works as are some questions I believe they're all in order but if you need anything please let me know and I will see you in the next lesson.