welcome to human anatomy and physiology here in our lecture series on the respiratory system we are at episode two and we're going to look at the structures of the respiratory system uh that fall under that General category of being in the conducting zone so once again the conducting zone are those structures in the respiratory system that do not play a direct role in gas exchange so they are really able to bring air in uh towards uh the lungs and towards the alvioli um but they do not directly uh play a role in gas exchange so here we are looking at uh several uh main structures of the respiratory system once again uh the respiratory system playing a key role when it comes to cellular respiration removing waste products such as carbon dioxide and helping to maintain acid base balance functionally as I mentioned in the preceding lecture episode the respiratory system can be divided into two zones the conducting Zone which we're looking at in this particular lecture episode and then the respiratory uh Zone which we'll look at in a subsequent lecture episode so looking particularly at the structures uh that we consider to be within the conductor Zone once again these are organs and structures not directly involved in gas exchange so um the conducting Zone includes the nose and nasal cavity which help to filter and warm incoming air following which air makes its way uh through the F ferx or the throat and that is essentially a muscular tube that serves as a passageway for air and food we also have a Linex or a voice box that contains the vocal cords as involved in sound production in addition we have the trachea and so air makes its way through the trachea and that is a tube that is reinforced with cartilagenous rings that help to keep the airway open to allow for air to pass into and out of the lungs the broni uh are also um located both on the right and the left uh side of the body allowing air to enter into the right and left main bronchi so they are essentially like a bifurcation off of the trachea allowing air to go from the trachea and make their way to the lungs following this we have bronchials and these are smaller branches of the of the broni that continue to subdivide or bifurcate into small smaller and smaller tubes lastly I'll just highlight um unrelated uh to um thinking about the conducting Zone but a key muscle um I'm going to highlight is the diaphragm and so we talked about the diaphragm in preceding lecture episodes but what you can see here is in fact it is that large Dome shaped uh muscle uh that plays a key role in uh breathing okay so getting back to the conducting Zone here we have uh the divisions of the ferx or when we think about uh the throat itself and there are three major regions to be uh cons uh considered so there's a naso ferx the oral fex and the Lino ferx the nasal ferx is uh uh within the nasal cavity and it serves only as an airway at the top of the nasal fex you also have the tonsils the oral ferx is a passageway for both air and food it is bordered superiorly by the nasal fex and anteriorly by the oral cavity lastly uh the Lino ferx is inferior to the oral fex and is posterior to the Linex and that's how it gets its name so essentially the FX is a tube likee structure that extends from the base of the skull to the esophagus and plays a role in uh both respiration but also um as part of the digestive tract notably I will also highlight that the oral fex and the linal fex uh because they are both a passageway for air and food have a unique type of epithelium and that's known known as stratified squamous epithelium uh and that uh is a very um important um delineation as it helps to protect against abrasive Movement of food the nasal fex as it is only an air passageway has a slightly different type of uh epithelium and that is pseudostratified colonar ciliated epithelium and once again it is unique because it has cyia and that is going to propel mucus to remove trapped uh dust uh bacteria Etc next here we have the Linex uh which extends from the linal fex and the Hy B to of the trachea and it really helps to regulate the volume of air that's entering and leaving the lungs you are not responsible for um understanding all of these various and naming all these various structures um this is once again uh just to highlight the LX um at a very superficial level the role um is um uh the Linex is really helping uh to form part of the airway to the lungs and protect uh the airway as well and it plays an important role when we think about respiration but also vocalization and swallowing here is an image of that pseudo stratified cated culer epithelium so once again this is uh the type of epithelium located in the nasal fex you can see this cyia located on the apical surface once again the cyia play a key role in uh helping to uh filter remove uh dust dust type particles bacteria um from the airway next we have the trachea which is a wind pipe that extends from the L next towards the lungs uh as as mentioned in the preceding uh lecture slides it does have uh cartilage uh haling cartilage in particular uh and uh this allows for the airway to remain open notably uh the trachea extends from LX to the right and left primary bronchi and the wall uh does contain smooth muscle importantly it does contain c-shaped cyousuke that there are elastic fibers also contained within the trachea I'll go back to those cynus rings for a second so as I mentioned there are c-shaped cynus rings that are made up of haling cartilage notably uh these rings are somewhat incomplete uh and so uh posteriorly there is a certain amount of elasticity that allows the esophagus to expand into the trachea during swallowing the main uh function as I've highlighted uh of the TR is to allow uh an open Airway to allow air to make its way uh to the Brony and uh to the left and right lungs respectively at the lower end of the trachea as I've mentioned you have two pro primary bronchi the right and the left bronchi which will go on to divide into secondary broni and continue to Branch into to uh bronchials and that concludes this lecture episode