Clinical Anatomy – Nasal Cavity and Sinuses



hello in this video we're going to talk about the clinical anatomy of the nasal cavity focusing on the sinuses let's begin about cutting a cross section or sagittal section of the nose and look at the general structure and revise the anatomy here is the nasal cavity the nasal cavity is bordered in fear early by the palate which consists of a hard bony palate anteriorly and up and under the back the soft palate which contains no bone of course you have the oral cavity here and the tongue here the epiglottis is a gateway to the trachea which connects the lungs the esophagus is the root to the stomach the epiglottis closes when we swallow the throat I guess we can call the pharynx and it can be divided into three parts the very top is the nasal pharynx which is in line with the nasal cavity the middle is a oral pharynx which is in line with the oral cavity and the bottom is a laryngopharynx where we have the larynx essentially your brain sits in this cavity here at the top surrounded by bone there's a small hole in the front of our skull you can say and this is actually a sinus and this is called the frontal sinus sitting at the posterior superior of the nasal cavity is another sign is called the sphenoid sinus of course we have actually more sinuses than this but it's good to know these two for now there are other important structures within and surrounding the nasal cavity let's take a closer look again so here again we have the nasal pharynx your hard palate and your soft palate at the back of the nasal cavity situated really within the nasal pharynx is a small opening where the eustachian tube also known as the faring go tympanic tube drains into this tube literally connects your middle ear to the nasal cavity so if we were to draw the inner and middle ear quickly this is your middle ear where you can find your auditory ossicles about the smallest bones in your body and this is the eustachian tube also known as the faring tympanic achoo the clinical significance of this is that if you have an upper respiratory tract infection this can subsequently cause a middle ear infection because there's this tube and it's a gateway to the middle ear on each side of the nasal cavity we also have these things called turbinates which are also known as in nasal conchae or a Conca for one there is the inferior concur middle concur and superior concur the function of the Conca conchae are to help warm and more moisturize air that is flowing through the nose now behind each respected conchae you have the nasal meatus some of the sinuses drain into the meatus this really tells us that the sinuses and the nasal cavity are joined together as well so for example the sphenoid sinus drains into the superior meatus behind the superior conker the frontal sinus drains into the middle meatus we can't look at the other sinuses from this angle because it's too hard now you can say the nasal cavity has two segments it has the respiratory segment which allows air to enter oxygen and also air to go out so carbon dioxide and the nasal cavity also has an olfactory segment which is the area which allows for smell essentially the olfactory segment is lined with a specialized cell type of pseudostratified columnar epithelium and these guys contain receptors for the sense of smell this segment is located in and beneath the mucosa of the roof of each nasal cavity these receptors will make up the olfactory nerve which is a cranial nerve number one and this will be carried back into the brain where smell is perceived finally it's important to mention the pouch here which is the sella turcica which translates to the turkish seat for turkish saddle and this is essentially the pituitary fossa with a pituitary gland sits of course the gland doesn't actually sit on it but it's rather pretty detected or encased by it rhinitis also known as coryza is irritation and inflammation of the mucosal membranes in the nose because the nose and sinuses are joined as we have learned Ryan itis can lead to sinusitis which is inflammation of the sinuses let's recap again the anatomy here is a superior conca middle conquer inferior conquer and behind each company you have the meatus so here you have the superior meatus middle meatus and inferior meatus here is your sphenoid sinus and frontal sinus this is your nasal pharynx and remember the faring go tympanic tube drained here from the middle ear now this is one angle of looking inside the nasal cavity but let us cut a coronal section and look at the nasal cavity and sinuses from the front to orientate ourselves this here is the orbit where the eyeball sits and here is our teeth this is your superior counter behind it the superior meatus this is your middle conker behind it the middle meatus inferior conker behind it the inferior Mientus below the orbit and lateral to the nasal cavity are your maxillary sinus the maxillary sinus like the frontal sinus drains into the middle meatus here are your frontal sinus which as we talked about earlier sits essentially above the orbit and they also drain into the middle meatus the ethmoid sinus is the fourth sinus we will talk about and sits medial to the orbit the ethmoid sinus drains into the superior and middle meatus sinusitis or should we call rhinosinusitis is inflammation of the sinuses a feature of someone with sinusitis is essentially redness or erythema around where the sinuses lie and so the frontal and maxillary sinus may appear red and irritated the pathophysiology of sinusitis as we have learned can be secondary to rhinitis rhinitis may spread to the sinuses producing swelling and inflammation of the sinus mucosa let's talk about complications of sinusitis so ethmoid sinus iris is a particular concern ethmoid sinus infection may break the fragile medial wall of the orbit allowing infection to spread to the eye which can cause blindness or even optic neuritis similarly frontal sinusitis can also cause some complications and this is shared with any sinuses sinusitis is basically but it can cause osteomyelitis for the frontal sinus if you have infection here the infection may or can invade the brain causing meningitis and even form an abscess in absolutely worst-case scenarios of course these complications are rare but it is good to know them nonetheless you

35 comments

  1. extremely helpful video, i couldn't visualise the concha and meatuses but your explanation really helped!

  2. had a FESS operation together with an inferior turbinoplasty. Because of that operation I received Empty Nose Syndrome (ENS). Daily pain and suffering, dry nose, anxiety. Think carefully before you do any operation to your nose.

  3. I really enjoy your presentations. As a Paramedic, I love the detail and fluidity of your episodes. This helps a ton with keeping me up with my anatomy and physiology. Don't stop you have an amazing talent and bring such wealth of knowledge.

  4. superb video! The drawn explanations are fabulous. I'll have to watch it at slower speed though as it was quite fast

  5. Although I read well I lack marks due to lack of diagrams in exams.
    I don't know how to draw diagrams.

    But now I think I can draw meaningful diagram.

    Thank you very much sir😍😍

  6. This was great, thanks, I been tryin to find out about "what can cause a sinus infection" for a while now, and I think this has helped. Ever heard of – Franaar Easy Breath Formula – (do a search on google ) ? Ive heard some super things about it and my mate got great success with it.

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