welcome to our first board exam review session so in this session we're going to review everything or all the important points that you have learned from oral facial class or from head and neck anatomy class so let's start with um learning about planes so planes are basically sections of the body so if i ask you a question or if you get a question on the exam that says um what is the plane that separates the body or structure into upper and lower parts so the plane that separates the body into upper part and lower part i hope you would say horizontal plane because it's right across the body horizontal plane is also known as transverse plane and when you see this plane over here it's dividing the body from its upper or superior part to the lower or inferior part what if i ask you a question that says what is the plane that separates the body into a front or anterior and back or posterior part so what is the plane that separates the front from the back the anterior from the posterior and the answer to that is i'm hoping you're saying frontal plane or coronal plane because that cuts the body in half where you have the anterior or the front in one section and then the back or the posterior in another section and lastly if i were to ask you what's the plane that separates the body or structure into right and left parts down the midline okay so if i want to separate the body from the right side to the left side then you would say it's the sagittal plane and what's interesting about the sagittal plane is that if you said if you said mid sagittal clean you would also be correct because when you say mid sagittal plane what that means is you're cutting it right in the middle like literally right in the middle and you get an equal amount of right side to an equal amount of left side but you can see in this picture they also have a sagittal plane here which is not right in the middle right and so you can still do that you can still have a sagittal plane like this where you have more um on one side and less on the other side but if we're cutting the the body right in half which is what we call sagittal plane and this is where you can have equal amount on the right and equal amount of body on the left so here are some true and false questions all references to the body structures are made assuming the body is an anatomic position true or false the answer to this is true but if you're wondering what anatomic position is let's look at the next statement anatomic position is the erect position of the body arms at the sides with head eyes and palms facing forward and this this statement is true because when you look at the anatomic position we're always looking at it when someone is standing up nice and tall and everything they're looking face forward and you can see how their arms are also positioned you can see that the palms are facing forward so that's what we um if you're ever taking an anatomy class when they're looking at planes that's what they're when we say an atomic position this is the position that the person should be standing in now there's also something called directional terms and these are terms you may see so when you're doing board exam case study questions they may use terms such as medial lateral superior inferior or dorsal and ventral and so let's look at some of these terms so i want to point out the tongue surfaces when we're looking at the tongue there is something called the ventral surface and also something called the dorsal so dorsal is on top okay so dorsal is on top and ventral okay so ventral is underneath the way i remember it is d alphabetically comes first so therefore it's on the top v is somewhat at the end of the alphabet so that therefore it's at the bottom so the bottom of your tongue is ventral the top of your tongue is dorsal and then the side of the tongue are known as lateral okay so lateral because it's away from the midline the middle is over here the midline is here to the side is lateral superior inferior may be a term that might come up so superior means something towards the top of the body and inferior means somewhat something towards the bottom of the body so for example the tongue is superior to the chin for example which is a mandible and here again we can see some um other examples of what's anterior and posterior superior means a wave or on top inferior means at the bottom so here's another question that might come up the term used to describe structure is located to where the surface of the body is and feel free to pause the video so that you can look at the answers and come up and see what you come up with so the answer to this is actually a superficial so the term to use the term used to describe structures located toward the surface of the body is superficial so think about um you know your skin your skin is superficial and everything underneath is more deep so deep is things that are located away from the body's surface whereas um superficial is something that's located toward the body surface or on the body so superficial is the answer here now let's look at some bone structures so we're going to look at what uh prominence means we're going to look at what bony depressions are and what bony openings are so let's start with bony prominences so there are many so actually let's look at this word this word here prominences is basically an area where there is a prominence on the body surface in other words something's sticking out so let's look at some examples of prominence some some examples of bony structures that are projected out so condyle condyle is this right here so in the mat this is the mandible we have a mandibular condyle okay condyle um a good trick uh to learn about the condyle i'll should talk about it later on but i can actually mention it here too so when you're looking at this this is a condyle imagine that there is a phone and you know the old phones where you have to literally dial the numbers and you you kind of like take you put your finger here and you turn it and that's how you get like one number and then you find your other number you put your finger in and you turn the the dial so that's how you can remember dial it's because if you look at this word this word may kind of remind you of dial so think of con dial so a phone that you have to dial like the olden times and so this over here is the mandibular condyle a tuberosity is seen the tuberosity that you should be aware of is the one that you see in the maxilla so maxilla like something called maxillary tuberosity and let me show you a picture of that so right over here at the top is the maxillary tuberosity so this stroll is like posterior to the third molar i turn this around um which is not that prominent here but there's usually a bump right at the back of the molar the last molar and uh that bump it would be known as a tuberosity maxillary tuberosity maxillary because it's on the top and tuberosity is like a projection that's just sticking out behind the last molar a tubercle which is the next one over here is a small rounded projection or process so right here right behind the mandible we have something called the genial tubercles which are the small projections round a rough process or projections that are sticking out that's a tubercle remember all of these are things known as prominences are things that are sticking out so the condyle sticks out the tubercle sticks out when we look at depressions depressions are things that have a depression ha are basically con concave so look at this right here this is your mandibular notch the depression right do you not see that that's a depression mandibular notch let's look at fossa fossa is a very common one so fossil is basically a deeper depression um and i know you can't really see it here but basically that depression that you see right underneath the mandible is known as the submandibular fossa fosacc or there's a depression sublingualism clear it's more near the tongue sublingual fossa is over here and again it's a small depression and this depression is where the muscle kind of attaches it's that area the reason why they have a depression is so that the muscles can attach there there is a digastric fossa right here which is right underneath the jaw then we have bony openings and with bony openings we have um some that i want to point out to you guys so we have something called the foramen and foramen is basically a window-like opening in a bone so we have if we're looking at the skull and we're looking at if we cut the skull and we're looking at it from the interior view we have lots of foramen we have a big one right here which is known as foramen magnum we also have a small one here which is a foramen ovale and there's so many different foramen that we'll look at when we get to the skull section but what i want you guys to know is a foramen is known as an opening and this is where the blood vessels and the nerves pass through we also have something called a canal a canal is a tube-like opening so over here we have a mandibular canal and in that canal we can see that the blood vessels or nerves are passing through here we can see another foramen another opening this is called the mental foramen which is at the bottom on the mandible we have a meatus meatus is a again a canal and this one is known as the external acoustic meatus so it's near the ear acoustic because that means sound and then we even have fissures and again in the fissures we can also have as a passageway for blood vessels and nerves so the one example from the skull is known as the superior orbital fissure orbital means i so it's near the eye and it's this line over this green thing that we're looking at here is known as the fissure here again is the view from inside the skull and we can see there's lots of formulas there's foreign magnum and i think of magnifice when i think of magnum i think of something gigantic like magnificent something huge so roman magnum is a really big hole and that's where blood supply and blood vessels come it's actually where the um brain and spinal cord kind of make their connection through this uh hole through this opening so for raymond and then we the way i remember that for raymond is an opening is um if i look type out this word here for raymond if i write it out oops like that and you can see there's an o there's an e and an n and you can cross this out and put p and so then i get open and so that's how i remember that foramen is an opening something that like a hole an opening and what is it an opening four was an opening for blood vessels and nerves she passed through so here's another question for you guys the term that describes a window like opening in the bone is called and if you said c for raymond you are correct so a foramen is a short window-like opening a canal is a longer tube-like opening such as the mandibular canal which is the picture we looked at right here the mandibular canal a meatus is a type of canal or channel within the bone so the one we looked at is the external auditory meatus which is by the ear and then we have the fissure and a fissure is a narrow slit like opening between two like near parts or adjacent parts of the bone and the one we looked at was the superior orbital fissure which is this one right here superior means on top so superior is this one inferior would be somewhere below orbital means i so it's near the eye let's look at the skull now so when we say um the neurocranium there are eight eight bones that make up the neural cranium so what does neurocrania mean your cranium are referring to bones that make up or that are around the brain okay so around the brain and there are eight of them so let's see if we can list them so the first one is this is not an accurate picture but basically all the things that are over here where the brain supposedly sits are um the bones of the neocranium so the first one is the frontal bone that's right here the very front then we have the specter so see the yellow part over here and then you can also it actually goes drop goes all the way to the yellow part here and you see how it looks like a butterfly in some ways um so here's one wing and then here's another wing so there's this sphenoid bone we also have an ethmoid bone and the ethmoid bone is right on the inside there's a small bone on the inside we have the occipital bone and this you cannot see but it's at the very back i'll show you that with the 3d model we have the temporal bone and think of your temple where's your temple where you know where does it hurt sometimes when you have a headache sometimes your temples start hurting close to the side that's your temple bone and your temple bone is paired okay so all the other bones are single temple bones up here because it's on this side and it's also on the opposite side and same with the parietal bones the parietal bone is a big bone right here that's on the side and you also see it on the other side so these two bones the temporal the one where your temple is and the parietal which is right on top over here are paired so let's turn this around here is your occipital bone which is at the one at the very back the purple one occipital and that's like to do with um your eye occipital in scene parietal is this one right here so we have two parietal bones one right here and one right here therefore it is paired we also have two temporal bones one right here and if i flip it the other one is right here temporal bone so these are all bones and this is the spinoid sphenoid bone this is your frontal bone and we also have an ethmoid which you cannot really see here but the ethmoid is a bone right inside here so there are eight bones that make up the neural cranium which is that's around the brain then we have facial bones and facial bones are there's 14 of them so there were eight bones that make up the brain or the neurocranium and then we have 14 bones that make up the face known as serocranium and what's interesting about this term over here are there it refers to the bones that are not on or surrounding the brain okay so 14 of them and you can see some of them are single and some of them are paired in this case two are single and the rest are all paired so when we say single what that means is just one bone is not a combination of two bones so mandible is single and your bone mark and your vomer is this line right here that's separating well that's basically where your nose is that's known as your boner bone and that forms like the very posterior part of the nasal subject the warmer then we have nasal bones and these nasal bones are paired and you can see there's one here and there's one over here and so that's why it's paired because it's a combination of two and your nasal bones make the bridge of your nose then we have lacrimal and lacrimal is hard to see in this um picture but lacrimal is right where your tear ducts are okay so right where your where we cry right behind that is known as your lacrimal bone lacrimal i think of tears psychomatic bone so this is your cheek bones zygomatic bones and you can see there's one and two therefore it's paired we also have an inferior nasal concave which is this um thing that you see that kind of slopes over like that that's your inferior nasal concave and we have one here and one there therefore it is paired we have the palatine bones i'll show you this in another image but the palatine bones is right under the maxilla we have the palette and they are paired because when i show you um it's basically two palatine bones that combine together to make a palette and you'll see a fissure um in the middle and then we have the maxillate which is this one right here so we have one and two they're fused together that's why it is paired okay let me show you the palatine bone so if i flip this over i'm struggling here okay here we go that is your palatine bone and then we have like a median or a midline palatine suture actually and that suture it basically it's um right here in the middle and the reason why the palatine bone is paired is because there's one over here one over here and it gets fused together and it creates and that's how you have that midline suture and the maxwell is also paired so we have one over here and one over here and then they merged together and again this lacrimal and you can't see it in this picture that well and we have lacrimals right by the tear duct psychomatic is the orange one right here you can see the foamer which is this line right here and i can't i don't think we can see the inferior nasal concave that well but there should be something sticking out from the nose inside and that it would be known as the inferior nasal concave this over here is your nasal bone so check out this question each of the following bones are cranial bones except one which is the exception occipital bone sphenoid bone ethmoid bone frontal bone or zygomatic bone which is not um a cranial bone which does not surround the brain so if you look at this picture these are all part of the cranial bones or the neurocranium but the zygomatic bone which is this one right here the cheekbone that is not part of it so the answer is e zygomatic bone that is a paired facial bone all the other ones are single bones all the other ones listed here are single bones of the neurocranium or cranial bones let's look at another question the horizontal planes of the palatine bones okay so this is a pallet articulate with each other to form the posterior portion of the hard palate an important landmark for the administration of local anesthesia is found here which is it so it's kind of self-explanatory because we were talking about the palette and the only one of the options that you see here is the greater palatine foramen therefore the answer is the greater palatine foramen and let's look at it foramen we know our openings these are areas where blood vessels and nerves pass through and so anytime we want to give a local an aesthetic to a client the needle has to be somewhere near the foramen near the hole where or near the opening and that's where you want to deposit the anesthetic because that's how you can numb the blood vessels and the nerves that's how you can um interfere with the blood vessel and nerves so greater polishing foramen that's this one right here this whole or this opening right here and when you inject in that area you would numb the palate on the posterior so let's continue on with the skull there are some other processes that we didn't talk about so remember processes are projections things that stick out so here we have the mastoid process which is right at the back we have the zygomatic process here's the zygomatic bone so it's a zygomatic process and then we have the styloid process which is right here which is that the thin thing sticking out and i remember learning that um the styloid kind of looks like stiletto heels so think of a stiletto heel that people wear and you can see that that kind of looks like the heel right so that's how you can remember that that's the styloid process so when we're looking at the inferior of the skull we have more openings and we're going to focus on these three openings so we have the four i mean foramen ovale which is this one right here and what blood vessels go through this one here well it's the one it's the one with the mandibular division of the fifth cranial nerve so the one that helps with the mandible foramin spinosum or you can call it foramen spinosum especially that's actually probably the proper way of spinning for raymond spinoza and with foramen spinosum when you look at it it is it's pretty tiny hole right here and this is the one that opens the me the middle meningeal artery mma so this is a branch from the maxillary artery foramen lacerum is right here foreign and that is the opening for the internal carotid artery so carotid means heart so again how can you remember this well foramen ovale okay oval does that kind of sound like oh man maybe oval or old man see if i can try to write this out for you guys so oval may sound like oh man and if you think of oval and old man think of man or mandible what about this one for raymond spinoza so this word this is actually something i got from student rdh this word spin can kind of sound like um spinach so when you think of this word you can think of spinach okay and then m m a when i googled mma i got something called mixed martial arts and so people who play mixed martial arts eat a lot of spinach if you think of that then that's how you can remember that foramen spinosum is where the mma artery goes through so that's right here middle meningeal artery and this is a branch out of the maxillary artery then we have the foramen lacerum and lasso is where the heart is the internal carotid artery and it's this one um where is the last room right here so this is the last room and i don't know think of lace or rum and you shouldn't or you can think of like a think of a picture of a heart and it's lacy maybe you wrapped lace around it and we shouldn't be drinking rum when you're having a heart issue so something like that think of something really funny or something unique something that will gets stuck in your mind and that's how you can remember that foreign lassorum is an opening for the internal carotid carotid artery when we look at the maxilla or maxilla what we should note is we actually are the processes so remember process is something that sticks out so frontal process this is a frontal process in the front it's going up towards the frontal bone and it's a process it's a projection psychomatic process it's a projection this is where your cheekbones are alveolar process alveolar process is where the bones are which is near the upper teeth alveolar process here is a great picture of the maxillary tuberosity so right behind the third molar area this is where the maxillary tuberosity and this is where actually blood vessels and nerves they enter the bone through here and this is where the maxillary actually the growth happens most um often here in the maxillary tuberosity and here is the palatine bones and this was the median palatine suture that i was talking about earlier here we have the greater palatine foramen we also have a lesser so the smaller one lesser for small palatine foramen and this this is the greater palestinian block is when we inject somewhere around here so that the palette at the posterior can get numb okay let's look at some major bones of the skull when we're looking at the mandible of the mandible so um we're talking about the mandibular condyle and we said think of it as a at the old phone and how you're dialing the phone so that's how you can think of the mandibular condyle this is the mandibular angle this is the mandibular ramus and remus kind of sounds like ramp so think of it as a ramp going up so remus okay it's like a ramp this is the mandibular body okay this is whole thing's the body so imagine a body lying down here and that's how you can think of it as your mandibular body this is the coronoid process remember process is something that sticks out it's a projection therefore a coronoid process is over here so let's do another question the maxillary tuberosity which is the right behind the third molar is a landmark for the administration of local anesthesia to which of the following a lesser palatine nerve b inferior infraorbital nerves or a c nasopalatin nerve or d posterior superior alveolar so the answer to this is actually the posterior superior alveolar nerve so we do where there's a block that's out there that can numb just the posterior superior alveolar so it's just in the maxilla okay the maxilla and you inject somewhere near the tuberosity which is right behind the third molar and that way you can numb the last the molar teat what about this one the posterior superior alveolar artery supplies blood to i'll let you have a read and let me know what you think and you can pause it pause the video so that you have some extra time so the answer to this is um c maxillary posterior teeth and periodontal and also the maxillary sinus so if you um inject somewhere in this area here by the maxillary tuberosity you can you can numb to the psa block which stands for the posterior superior alveolar block there is an artery near that that supplies blood to the maxillary posterior teeth and the sinus when we had looked at the other options so for example a the mandibular teeth and floor of the mouth well which one which block numbs that one mandibular teeth and floor of the mouth so if you look at this picture this is the mandibular mandibular teeth and this is the floor of the mouth so we can see ia ia stands for inferior alveolar block so the inferior alveolar block it hits the it's near the mandibular foramen and the mandibular foramen is like right at the back somewhere here there's an opening right at the back over here so the needle has to somewhere how go goes near there and that will numb the inferior alveolar artery and therefore cause this block which will numb all the areas that you see in green we have the hard and soft palate so to numb the palette you could do a nasopalatine block and you would numb somewhere around here okay so you would numb somewhere around here and then you could numb the palette here the hard palate you could also do a greater palatine block and that would numb the palette over here or over here depending on which area you numb we also have we were talking about the psa block and the psa block you aim it you aim the needle towards the very posterior and you could numb the last repeat what they're saying though is the mesial buccal roots remember the maxillary teeth have three roots the mesiobuccal root may not always be numb so that's something to watch for we also have something called the infraorbital block so i'll show you a picture of it inferior orbital block is the one in blue and what it does is it numbs all this area over here including and up to your nose so sometimes your nose and just lower eyelid can feel a little funny and that's because we have a foramen over here it's called the infraorbital foramen think about this word infra means inferior to an orbital means eye so it's a hole an opening it looks like this right underneath the eye and you can see there's lots of arteries and blood vessels you know in that area and so if you numb up here if you numb somewhere here um what can happen is you can numb all these teeth over here and i'll show you exactly which state the anterior on one side okay and then some of the in the premolars as well and your lip will also feel swollen up to your eyelid the lower eyelid okay let's move on to sinuses so we have four sinuses that we should be familiar with we have the frontal sinus which is right near the frontal bone we have the ethmoid sinus which is near the um ethmoid bone we have the maxillary sinus which is right above the maxillary bone maxillary bone and we have the sphenoid sinus which is further in and again that's close to where the sphenoid bone is and what happens is i don't know how many of you guys have ever had a sinus infection but your head feels or your yeah your head feels really heavy because what happens in a sinus infection is that you get fluid buildup so you get fluid over here you can get fluid over here because sinuses right now if you if your sinuses are clear you're you'll feel normal and these are actually air socks and when you have an infection now you get like built up over here and then that's when you feel um yes when you get headaches and infections could be happening so the sinuses that we should know are the ones called that we can say fems and femi stands for frontal ethmoid maxilla and sphenoid sinuses so let's say you do have fluid build up here under frontal sinus how does it eventually come out how does it drain out well it has to drain through something and so there are inner nose we have something called a superior meatus which is this one here then we have something called the middle meatus which is right here and then we have something called the inferior meatus and remember a meatus is just like a like a tube and so it's really easy to remember superior middle and inferior because superior is above middle is in the middle this is meatus so this tube is in the middle and then inferior is below this is the one that's where this below and so we have fluid in the frontal sinus they actually come down and they actually drain into the middle meadow so they drain here and then sometimes we swallow it so they come out or we can spit it out so you know how many have plum sometimes okay so middle meatus frontal sinus drains into the middle meatus the sphenoid sinus which is right over here if you have like fluid here it needs to come out somewhere you can see it comes out into the superior meatus and you can see it's quite close right so it drains into the superior meatus the maxillary sinus which um is near the maxilla it would also drain into the it's sorry that the maxillary drains into the middle meat so frontal drains into the middle meatus and maxillary sinus which is further up i don't have a picture of it drains into the middle meatus the ethmoid we also have an ethmoid sinus which is if you look at this picture it's right over here so it's quite inside and the ethmoid sinus also drains into the middle meatus what's interesting about the ethmoid sinus is if you look at the ethmoid sinus you can see we have like a front a front partner anterior part a middle part and a posterior part so the anterior and the middle part of this fluid there it drains into and this is what it says here the anterior and middle um ethmoid sinuses determine into the middle meatus but the posterior so the one at the further back the posterior sinus or ethmoid sinus that drains into the superior meatus the sphenoid sinus also drains into the superior meatus so there's a question that says all of the following perinasal sinuses drain into the middle meadows of the nasal cavity except one which one is the exception posterior ethmoidal sinuses anterior ethmoidal sinuses frontal sinuses or maxillary sinuses and the answer is posterior ethmoidal sinuses because as we said the very back the posterior ethmoidal sinus that actually drains into the superior meatus but everything else so the anterior ethmoidal sinus the frontal sinus and the maxillary sinus that drains into the middle meatus let's move on to something called cranial nerves so you know this is our brain and in our brain there's like actually 12 different types of nerves the 12 pairs of nerves that you can see on the very bottom of the brain this is the very bottom of the bro the brain and what's unique about these nerves is that they send um information to like the organs they control muscles they can control glands um you know they can even control the heart and lungs so it's really interesting when we learn about the cranial nerves and there are 12 of them the one that i have circled are the ones that you should know because they're the ones that relate to us in our individual field so for example there's the trigeminal nerve which is the fifth nerve and that one you can see over here it um affects or it's like it helps with the face the sinuses and t so it gives feelings it gives blood supply um to the face sinuses and teeth we also have the glossopharyngeal nerve and glosso means tongue so that's how i remember it's near that is for the tongue the posterior part of the tongue we have hypoglossal this is the muscles of the tongue so again colossal for tongue we have facial these these control the muscles in our face um yeah i think those are the four that we should actually know so if you look at the cranial nerves there are many different things that are out there that can help you memorize them so for example there's like 12 letters here and and if you look at this one to touch and feel very giant volcano ah hot so the o stands for olfactory because that is one of the um first nerve right then the other always stands for oculomotor and ocular motor is for eyes so olfactory object oh actually they've switched it around so sorry this is number two optic then oculum made motor right so that's a good way to memorize it and here is a table that has all the numbers all 12 their names and what they actually do so what do these nerves do so olfactory is for smelling optic we have that nerve so it helps us see ocular oculomotor we have that it's a motor right motor means movement we have this nerve is there to move the eye in pupil and the ones that um affect us in the dental field is trigeminal because that helps with us feeling the base we also need facial nerve because that helps move the base of the muscles in our face it also helps us salivate we have the glossopharyngeal that helps us taste and swallow and we have the hypoglossal which helps us move our tongue so there's many different ways you can um memorize this so yes we have this mnemonic right over here but we also have this video that i do encourage you to watch and it um i like how they've done this because what they have said is for example five facial osiris if you look at five right here five is the trigeminal nerve okay and facial nerve is seven so let's look at that this is the seven and that's outlining the entire face so that's how you can tell it's a facial nerve this is five right here trigeminal so the trigeminal nerve is for face sensation it helps you feel the face and now the facial is helps are the muscle movement helps you move the base so that's why seven is my face and then eight you can see that's the ears right and so if you look at eight it's for hearing and balance right the ears for hearing and then the balance also has to do with the ears as well if you look at let's say let's do another one we look at one okay so one is olfactory that's the smell so one is kind of like the nose so it's really cool how they've laid it out so do look at this video so that you can be familiar with how the cranial nerves work so the facial nerve which is one of the cranial nerve is number seven a good way to remember the different branches are just by looking at the put your finger there and you can see cervical means the bottom this one is the mandibular buccal means cheek psychomatic is right above the cheek temporal is right by the temple and that's how you can remember those different branches so when we're looking at or what we're going to look at now is muscles of the face we can make lots of different movements in our face and the re the reason we can do that are because of different muscles we have on our face so all these muscles in our face we have and they all do unique functions so here's a table that outlines the different um muscles and what they do i'm going to look at some of them so when you look at this table it says origin and insertion origin is basically um where the muscle basically it's starting is right at the it's it's usually always at an area that's less movable so it's like a bone that doesn't move as much and then insertion this is where the muscle attaches to and that is usually more movable it usually attaches to something that you can a bone or something that you can move a lot more easily so for example if we were to look at the zygomaticus major okay zygomaticus major is um the major muscle right here and this one actually helps you smile so the reason why we smile is because of our zygomaticus major muscle and so if you look at the origin the origin where it's um it always attaches itself to a less movable uh structure so the zygomatic bone it starts more at the zygomatic bone and it ends over here it gets inserted right by the mouth the skin at the corners of the mouth because the mouth is more movable you can bring it up right the mouth is more flexible so do have a look at all these muscles and know what they do so for and it's actually not that hard to remember because if you think of it um psychomatic is major if you think about what this muscle does it pulls up the mouth and because it pulls up the mouth it helps you smile whereas the other one is at the bottom it's called depressor labia and for inferioris which is right here what does this do it lowers the lip right so it depresses the lip so the lip comes down into a frown if you look at the um see here this muscle is really important the orbicularis orbits so the oh oh orbicularis oris and that muscle actually helps you with the i just want to see what you see is that here um with the shaping of the lip so sometimes when we're talking sometimes when we actually make that o sound um the orbicularis or is helps you with that movement we also have the orbicularis oculi and oculi rounds with i so that's how you know it's the one and it's like it's like a round muscle like that so o is round shape therefore o is round shape here same thing with orbicularis oris i look at the o when i think of it as a round muscle so this helps you open and close the eye sometimes when we're scrunching our forehead the frontalis muscle is responsible for that or the corrugator muscle is also responsible let me show you their their muscles right here so corrugator is right here and sometimes you can get that scrunching of the forehead from that muscle right here so the muscles of the facial expression are innervated or supplied by so if you said a you would be correct the facial nerve okay so the facial nerve which is number seven it supplies the muscles of facial expression so all these muscles here that we were looking at earlier that causes all these different movements the reason why that is happening is because of the facial nerve which is number seven the other one that we are familiar with is the trigeminal nerve and the trigeminal nerve which is number three sorry trigeminal nerve is five the reason why we see three here is because the trigeminal nerve they have three branches so i can actually put that here so they have branch one and branch one is um the up is for the eye so it's called the ophthalmic so that it's a nerve that goes straight to the eyes and it helps with the eyes branch two so v for five because trigeminal is the fifth nerve and we say two and that is for the maxilla or maxillary nerve so i'm going to put maxillary nerve here and then we have v3 which is what this one is referring to and that is the mandibular so the trigeminal nerve has three different branches that supplies um or innervates the nerves near the eye the nerves near the maxilla and then the nerves near the mandibular and so this one the v3 mandibular that's where muscles of mastication so when we're chewing the mandible plays a huge role when we're chewing and so it is the trigeminal nerve that helps with the muscles of mastication with the muscles of chewing here's another question the muscle facial expression that assists the muscles of mastication jiren chewing is what so when we're chewing we have lots of muscles what muscles help us with chewing if you say bassinator you are correct because this muscle right here the business which is right here that's the one that helps us with chewing it helps us um with holding the bolus of food so you know how when we're chewing and then we get that bolus of food and the basinator muscle helps us um with chewing by maintaining that boneless position let's actually look at what all the other muscles do so the risorius muscle what do you think that does this muscle is actually responsible for fake smiling actually i'll show you a picture of what it actually looks like when that muscle is used so right here do you see how it's a big smile he's not really smiling with his eyes and that muscle is because it's such a small muscle it just pulls the the mouth out a little bit into a big smile so it's an insincere smile when someone uses that muscle then we have the mentalis muscle and the mentalis muscle which is listed right over here is right underneath the skin of the cheek so it's right at the bottom i know it's not listed here we can actually see it over here i think the mentalis muscle is this muscle right over here and what the mentalis muscle does is it protrudes the lower lip so when you're pouting um you know when you're upset on your podium think of a kid that's potent because he just got in timeout for example he uses the mentalis muscle to cheap out we have the orbicularis oris muscle and the orbicularis os muscle is the one right here that is around an auris kind of looks like oral so that's how you can remember it around the mouth and the orbicularis orange muscle it helps you shape the lips so when you're speaking um it helps you with that speaking orbicularis or is because it surrounds the lips let's look at muscles of mastication so muscles of mastication are the muscles we use when chewing now remember the muscles of facial expression one of the muscles of facial expression was buccinator which is uh it does assist with chewing but when we're looking at these muscles over here the muscles of mastication bassinator is not included okay what we're going to look at is the mmtl muscles masseter medial pterygoid muscle temporalis muscle or temporal muscle and lateral pterygoid muscle and the way you can remember this is you can have a mnemonic like my mom tells lies or mom makes tasty lunches our mom makes tasty lasagnas whatever way that works um for you so mmtls are the muscles of mastication and let's look at them so we have the masseter muscle and the masseter muscle is like right here and it helps elevate the mandible what does that mean this is the mandible that helps bring it up it helps bring the mandible up so that you can chew we have the temporal muscle which is a really big muscle right here that's near the temporal bone and what does this do again it helps with bringing the mandible up it also helps with retrusion of the mandible so bringing the mandible back sometimes you want to bring the mandible back that's what retrusion means then we have the medial pterygoid muscle and the medial pterygoid muscle is like right here and you can't really see it over here because the masseter muscle is blocking it but it's right underneath and that's the medial pterygoid muscle and what does that do it also elevates the mandible it brings the mandible up we also have the lateral pterygoid muscle the lateral comes off to the side and what does that do that actually depresses the mandible so it brings the mandible it opens the mandible allows us to open our mouth so the lateral pterygoid muscle allows us to open them out and it also helps with um protruding so bringing the mandible forward so um we looked at retrusion which is done by the temporalis muscle which brings the mandible back the lateral pterygoid muscle brings the mandible forward protrudes it now the thing is how can you remember whether it elevates the mandible or whether it depresses the mandible so the way to remember this by students is by student rdh is when you look at this word medial and you say the word me when you say me so this is when you're saying the word me what happens is when you're saying the word me your mandible closes but your mandible is closed but when you say the word la try it say the word la when you say the word la your mandible opens and so when you're saying la your mandible is opening so that means you're depressing the mandible because the mandible is going down so the muscles of mastication we know that it is innervated or is supplied by the fifth cranial nerve which is the trigeminal nerve and it's the third part of the fifth nerve so remember we said that there is a mandibular division the inter-trigeminal nerves have three divisions it has the optimalic division it has the maxillary division and the mandible division which is a third part so the muscles of mastication is done by the trigeminal nerve v3 to be more specific and three because threes refers to the mandibular part which is right here so here we can see it better here's the trigeminal nerve the trigeminal nerve is the fifth nerve and we can see there are one two and three branches so the third branch which is the mandibular branch that's the one that helps with the chewing you can see how it basically is surrounding that entire part over here that is where the chewing muscles are the muscles of mastication are so question relating to this that you might get is something called which of the following muscles originates partially from the maxillary tuberosity so maxillary tuberosity is an area right here just right behind the third molar which of the following muscles originates partially from the maxillary triburosity [Music] medial pterygoid muscle let's see why if you look at the medial pterygoid muscle you can see that it's just it's right near the maxillary tuberosity which is right there so the medial pterygoid muscle it originates from the maxillary tuberosity right here and then it ends or inserts rather at the medial side of the angle of mandible so the answer is medial target muscle because it's very close to the maxillary tuberosity and then it inserts at the side of the mandible the only muscle of mastication that depresses the mandible or opens the mouth is which of the following if you said c lateral pterygoid muscle you would be correct because lateral remember when you say la the word lateral you're opening the mouth right when you say me you're closing your mouth so depressing of the mandible or which means opening the mouth is done by the lateral pterygoid muscles we also have the hyoid muscles when you're looking at the hyoid bone which is right over here there are muscles that are above the hyoid bone there are muscles that are below the highway bone and these muscles what they do is they again they help with depressing or opening the mandible so they open the mouth and they can also even retrieve the mandible they can also put the mandible back so it's important to know what the muscles are that are above the um hyoid bone and then the ones that are below the hyoid bones so a question that you could get asked is all of the following are suprahyoid muscles except one which one is the exception and so let's look at all of them and if you said c diro hybrid muscle you would be correct because supra means above right think of your thyroid gland which is below which is you know further below so that's why your thyroid muscle would be below digastric this is where like the mandible the jaw is so that would be close to the that's part of the suprahyoid muscle style ohio this is near the stiletto um heels and i'm thinking of the styloid process which is more further up so it's above the hyoid bone and genial hyoid if you remember the genial tubercles again that's under the mandible so that's it's considered a suprahyoid muscle right so when you're looking at these muscles try to understand where they're coming from looks because that can actually help you figure out okay which one stays on top and which one stays on but the bottom so thyroid is at the bottom sternum right that's more at the bottom so underneath the hyoid bone so if you know where these words are coming from and what they mean they will help you in learning the location of these muscles okay that's it for now in the next video we will move on and we'll talk more about the arteries and discipline and the veins that you would see this um in the face we'll also be looking at the root morph well should actually be looking at the salivary glands in the next video and we're going to look at the lymph nodes and we're also going to look at root morphology all that will come up in the next video