okay Anatomy students welcome to our second video that we've ever done here this is our first video for our new bone unit as you can see this is a unit on the cranial bones our objective hopefully at the end of this video you'll be able to correctly identify all eight cranial bones there are eight that we need to know so we're that's a really nice and straight line there eight that we need to know out of the 206 bones in the body so after today you'll have less than 200 to go great let's get started first bone let's get rid of those first bone that we want to take a look at is the frontal bone it's highlighted here we see the frontal bone also on the front it's also known as your forehead frontal bone top of your orbits top of your eye sockets right where your eyebrows would be it contains sinuses some of those sinus headaches you feel first feature that we need to notice is the coronal suture you see this zigzaggy line right along the top of the skull when you think of corona and hoping you think of that's right and Eclipse and the corona going around the Sun I'm sure that's what we think it's like a crown going on the top so we have the coronal suture that connects the frontal bone to the parietal bone which is the bone right behind it and there's this little zigzag line where the bones have actually grown to each other now in infants when they're born you've heard of soft spots it happens because the bones of the baby's head have not fused together yet they haven't grown all the way it's due to that way that baby that that bones in your head form it's not endochondral ossification but intramembranous ossification where a membrane that surrounded the brain turns into bone and we get those soft spots or fontanelles so we have the coronal suture another feature that we want to be able to notice on our frontal bone is the supra orbital framing so if orbital is I super must be above the eye and we see one super orbital frame in there and another one right there they're like little holes if you will see on the frontal bone that blood and blood vessels and nerves pass through alrighty so frontal bone we need to know the coronal suture and supraorbital for Raymond moving on next to the parietal bones again what was this suture it's called the coronal suture so for the parietal bones these are going to form the sides of your head so either side top of your skull here sagittal suture is what's connecting these two together now you should be able to think to yourself what must be meant by sagittal suture it's a certain plane that goes through our body as we look here this is a top view here's our frontal bone here is a sagittal sorry there's a sagittal suture right there and here's a parietal and here's a parietal bone so we're looking right at the top view you can see how it's all crazy squirrelly in between here and kind of locking these two together in class you'll see that these bones do not come apart they are pretty well fused together with these sutures you're in luck the parietal bones there are no other features you need to know just the suture the sagittal suture there are two parietal bones moving on to the temporal bones temporal kind of sounds like your temple this would be the side of your head you see this weird shaped bone okay temporal bone has a lot of features so there's two of them one on either side the first feature will start with the suture it's called the squamous suture go back squamous suture and it comes right along here on the side on both sides we have a squamous suture so let's keep going if you look here on our side view again you can see the squamous suture right here they're taking it there's the bone by himself you see lots of weird things I see a bump down here a little needle part there and a little bridge going off to some place so let's take a look at these first one is the zygomatic process zygomatic process is this little projection sticking forward it's called the zygomatic process because there's another bone in fact this bone right here is called the zygomatic bone the zygomatic bone touches the temporal bone and the temporal bone touches the zygomatic so the temporal bone has a Daigo Matic process what would the process be on the zygomatic bone that touches the temporal bone it's called the temporal process we move on now to the mandibular fossa mandible is this jaw and the fossa as we know our depressions you can see it right here it's right by the ear it's this depression that you're seeing here is part of the reason why when we yawn it sometimes pops our ears you can hear this kind of popping that goes on when we yawn okay we next start with the auditory meatus MEA this is more than a foramen it's like a tunnel all right we can see it labeled there so this would be our ear canal would go in there okay so with the auditory meatus you can actually see them coming out on the other side because this is the inside view of the same bone you can see the internal auditory meatus and the external auditory meatus moving on to the mastoid process when I see the word mastoid I want to think massive and that is this big ol one right here at the very bottom this is what's actually connecting your neck muscles this big huge muscle that comes down your throat that you use to find your pulse called the sternocleidomastoid it's connected to the mastoid process allows us to move our head around big huge muscle connects to this big bump on the temporal bone the mastoid process next point is this little knife point it's called the styloid process and when I think of styloid process I think of stiletto heels think of those little pinpoint heels we can see this little pinpoint thing it's called the styloid process it's an attachment point again for muscles that control actually your voice box as you lift up your larynx up and down muscles are attached to the styloid process alright so again this is the temporal bones moving on now to the occipital bone only one of them you see it's on the back of your head back of your head the features that we're going to take a look at here first is the suture again it's lambdoid suture now you might be wondering lambdoid have something to a sheep has more to do with this letter called lambda if we look at what the landed suture looks like you might notice it it has that same shape or maybe it's for some of you guys it looks like a Mercedes logo here almost could be a peace sign there you go all right so we have the lambdoid suture that's what connects it to what would these bones be here on either side hopefully we know give you a hint parietal with the big P we then take a look at our features the first one is the foramen magnum when I see Magnum I think big again and that is a big hole if I flip this bone upside down you see a gigantic hole right there any guesses what goes through the hole your brain stem connecting to the rest of your spine foramen magnum we then have the external occipital protuberance or if you want to be cool you can call it the e o P that is this bump right here at the back of your head in fact if you feel on your head right now you'll be able to feel a bump right back there okay and the muscles connect from your neck all the way to this thing so when you put your head up muscles are pulling on your e Opie there's a famous eat external occipital protuberance you maybe have seen this character right there and cute Pluto has this gigantic bump on the back of his head your dog if you ever scratched your about your dog between the ears you might feel that bump so it's a big bump on the back here head the external occipital protuberance you can see it down there on that one as well here it is as well in that model there our last one are the occipital condyles a condyle is we know is a smooth rounded projection that's going to allow two bones to articulate and in this case oh and get rid of some of those lines this guy is going to articulate with the vertebrae the very first vertebra on your knit on your spine it actually allows your head to go up and down we say yes motion the condyles are actually rubbing on the first vertebra c1 we'll learn more about them later on again these are the occipital bones let's move on next we have the sphenoid bone very funky worse sphenoid you can see its location he's pretty much in the center the sphenoid bone actually touches every single other cranial bone again being a cranial bone that means these bones form the skull cavity that holds our brain and the sphenoid bone is kinda like the Keystone bone it touches every other bone in the skull I mean of the cranium at least it doesn't touch the mandible all right in this fee knowing that we need to know is this something called the sella turcica which literally translates into turkey saddle and has nothing to do with turkeys this is this special little room for a very important gland that we've studied a lot in our last unit called the pituitary gland this is a little home for the pituitary so if we take a look this little spot right here the pituitary gland is going to sit right in there all righty it's like the most protected place in your body pretty much you're inside the skull already and at the center of the skull in this little room is where the pituitary is going to sit you can take a look if you pulled the sphenoid bone out of the skull it kind of looks like a little batwing kind of situation going on here and you can kind of see the outline notice the bones it touches it touches this bone the blue one we notice the hopefully we know it's frontal it touches this green one on both sides that's the parietal I hope we know touches these pink ones which we know are called the temporal and the blue one that we just covered right here which is the occipital hopeful you can finish it and then there's only one more bone to look at and it's just a little gray one right there right in the very middle of the skull let's take a look at that one next all right the last bone that we need to learn is called the ethmoid bone ethmoid bone we got a nice arrow pointing them out here's our side view we should hopefully be able to recognize all these other bones you can see a nice great view here of that turkey saddle right there the sella turcica and right there's where the pituitary would just chill out in that little saddle all right so let's take a look at some features of the ethmoid bone first is the crista galli if you've ever wondered how the brain sits in the skull without just like floating and banging around on the walls the brain is actually anchored to this little sail right here called the crista galli let's circle him in green make him show up so that's called the crista galli right there and it says little sail that anchors the brain like a membrane wraps around the whole brain main surrounds it completely and is anchored here when we get to the cat dissection you try to remove your cat brain to see the pituitary you're going to break this attachment point here okay it's kind of a little a good important place in your brain okay I kind of anchored up there the front another feature is something called the cribriform plate now we're going to see that guy nearby here it's going to be on the side because all the little holes got better images to show you here in a moment about the cribriform plate a lot of your olfactory got a little nerves for your sense of smell and stuff is going to be traveling kind of through that lots of little small holes you'll see that easily on there in our class we next have the perpendicular plate perpendicular plate if I get rid of these other lines it's what makes up this vertical part of the nose in fact where the word ethmoid is written you can actually see where the word ethmoid is written this is the perpendicular plate that's going up and down it's perpendicular to the horizon okay next we have nasal conchae or turbinates these are really important for helping you both warm the air that you breathe in as well as help filter if you guys have ever been in the snow and you take a big deep breath of cold air and your mouth is open you can actually feel your lungs get cold whereas if you breathe through your nose the nasal conchae help actually warm the air on its way in plus it's got this increased surface area that helps swirl the air and help you filter out the dust to make boogers basically so take a look here's the crista galli here's a nice view of it right here F Boyd bone I see the cribriform plate right there on the sides I see the perpendicular plate vertical here here's another view of it kind of a color version as again cribriform plate right here along the side this blue area is actually Carly's we'll learn about that with the facial bones too in the next lesson but you can see part of making up this nasal septum do we see these weird oh go back do we see these weird little bulbs on the side these are those nasal conchae the things that are going to help swirl the air inside your nose as you breathe in and can warm it and help filter it alright that finishes all of the bones let's do a little bit of review so you're going to want to pause Epps you need maybe take a piece of paper out go ahead let's write down the question which cranial bone touches every other cranial bone you can pause think your answer if you wrote down sphenoid bone you got a right just go to question number two take the time write it down what keeps the brain from freely moving around in the cranial cavity hit pause your answer a membrane surrounds the brain and anchors it to the crista galli on the ethmoid bone last question why are infants born with soft spots on their skull and how do cranial bones form go ahead hit pause write down your answer newborns lack sutures because the individual cranial bones haven't grown together cranial bones form through intramembranous ossification all right that does it we'll look forward to seeing you guys in class and you guys get more chance to do some hands-on practice identifying these bones great job