Transcript for:
Understanding Skull Anatomy and Structure

Alright ninja nerds! Today we're going to go into the anatomy of the skull. Alright so, if you look right here, there's this actual suture running right here this suture is called the frontal or the coronal suture. It's basically separating the frontal bone from the two parietal bones here. Okay, then we have this suture running right here, right down the middle. This is called the mid sagittal suture, where you can actually just call the sagittal suture. Here's our sagittal suture and separating the two parietal bones here. I'm going to flip it over here and if you look over here, we're going to have this other suture running right here in the back, this is called the lambdoid suture right here. This is what basically separates the parietal bones from the occipital bone. Then if we come over here, on the other side we look here, let me fix this for you guys, this right here is going to be called the squamous suture. So this is our squamous suture right here, separating the parietal bone from the temporal bones. Alright so, now that we covered out those sutures, this is going to kind of help us to differentiate what's separating the parietal bones from some of these bones that we talked about. Let's go ahead and talk about the front of them. So here is our frontal bone right here, if we look at the front of them there's a couple different structures I want to talk about. If you know these guys right here, these are your orbits. Alright so that's what holds the actual eye right? Then if I kind of like scrape the surface here, right above the orbit scrape that surface, that's called the supraorbital margins right. So I'm scraping the surface here is a super orbital margin. If you look, it's right here in this part here there's like a little notch, that's called the super orbital notch or foramen, okay. Then if I kind of like look here, there's these lumpy parts here on the frontal bone. There's hollow cavities behind this area here, it's called the frontal sinus and the frontal sinuses on both sides here. They're going to be paranasal sinuses, which means that they drain into the nasal cavity, alright. Then if you look right here, just this surface right here, this is called the glabella, okay. So we have the glabella, supraorbbital margins, supraorbital notch, orbits and get the frontal sinuses. Inside the skull, we're going to have this big like little fossa, this divot and this divot right here, it's called the anterior cranial fossa. Alright so that covers the frontal bone. So within the frontal bone we've already covered those structures, now let's go ahead and move over and let's go look at the occipital bone. I'm going to put this cap back on here, okay. If I look here on the occipital bone, there's this structure right here. If you look here, it's kinda like a nice big bump called the external occipital protuberance, so this nice big bump right here it's called the external occipital protuberance. Now, I'm going to come in here. There's these little lines right above the external occipital protuberance moving laterally from that point, this is called the superior nuchal line, alright superior nuchal line. These nice little articulating surfaces here called the occipital condyles, called the occipital condyles, so they articulate with the articulating surfaces of Atlas. Now what I'm going to do is, there's a nice little hole here, I'm going to show you if you look there and I'm going to kind of show it like that. That right there is going to be called the hypoglossal canal. Where that pipe cleaner is going, so the pipe cleaner that's running right through that hole is going to be called the hypoglossal canal, for the hypoglossal nerve runs through, alright. If you look here, there's going to be like a little divot here, okay. This is called the condylar fossa. It's called a condylar fossa right there, this little divot right there. Then there's a little hole, the little hole called the condylar canal okay. So the condylar canal right in there. Alright now, that we covered those bases of the occipital bone, let's go ahead and move over here to the temporal bone. So if you remember, temporal bone has that squamous suture right there, right? Now this breast like process is going to be called the mastoid process. The mastoid process and inside the mastoid process you're going to have a hollow cavity which accumulates the mucous and that's going to be hollow a hollow cavity. It's going to called the mastoid sinus and this is not paranasal, so it doesn't drain into the nasal cavity. This right here, this little hole here, that's your external acoustic or your auditory meatus, right? So external acoustic meatus, right? That guy right there. Now, I'm going to flip it over, but if you look over here, I got this little like stylus looking thing, looks kind of like a little point that's called the styloid process, right there. It's called the styloid process. Then there's a hole, I'm going to poke in here. Right in between these two, if you look this is the mastoid process, that's your styloid process, the hole right between these guys which is called the styloid-mastoid foramen for the facial nerve runs out there. Okay, now a couple other things I want to talk about before we move on. This little process coming off the temporal bone is going to be called the zygomatic process of the temporal bone. Over here we got the zygomatic bone right there. Right so, here's our zygomatic bone. there's a process that comes off of the zygomatic bone and that's called the temporal process. So if you look at it, we have the temporal process of the zygomatic bone and the zygomatic process of the temporal bone and they form the zygomatic arch right. And then one more thing, I'm going to pull this mandible out. If you look this little jelly cover thing right here, this is actually called the actual temporal fossa or the mandibular fossa. Right so this is where the actual mandibular condyle, they stick into the mandibular fossa right there, and they form the TMJ joint, the temporal mandibular joint right. So here we got in there, again you get that mandibular fossa right alright. So that covers that part, but that's important now what I want to do is, I want to go ahead and look inside the skull. So if you look here, this guy right here we're going to look at the ethmoid bone. Right here, this guy right here is called the crista galli of the ethmoid bone. So it's one of these little shark fin like structures that pop-out up into the cranial cavity. So this is called the crista galli. There's a plate, right here right here, where I'm poking right there and that's where the olfactory foramina, which is these little holes, for the olfactory nerves run out through. This plate which has the olfactory foramina on them is going to be called the cribriform plate, right. Now again, there's a little olfactory foramen on where the olfactory nerves run up through okay. Then we already told you that this was the anterior cranial fossa. Now if you look here, there's a little fang like things right there. Right, these little fang like structures are going to be called the anterior glenoid processes, anterior glenoid processes. Alright, and then if you look right here, I'm going to kind of make a circle here. I make a whole circle, this whole circle that I'm making is going to be making up, what's called the sella turcica of the sphenoid bone. And The sella turcica means turkish saddle, so if you look here where like someone would put their butt inside the saddle, this is called the hypophyseal fossa. That's where the pituitary gland sits. Then we have what is actually I was called the dorsum sella, which is here in the back and then you get the tuberculom sella, which is in the front. And then right here, we have this wing here, it's kind of like the left wing, it's the small one right so this right here is going from here to here that I'm scraping over, this is the lesser wing of the sphenoid bone. We'll show you in another video, the sphenoid bone individually. But this right here, coming out from this side and this side, here this is the greater wing. So greater wing here, greater wing there right. And if you look here, I'm going to poke a hole right through here, I'm actually gonna use a pipe cleaner. I put a hole right through that ,that is actually called the optic canal. Ill show you from the front. So there's going to be called the optic canal and that is where the optic nerve, cranial nerve two comes through. This one is actually going to be called a superior orbital fissure alright. And it's better seen in the orbit, so I want to flip around here so you can see it there. So there's actually going to be the superior orbital fissure. Alright, that's your superior orbital fissure. A lot of nerves run through that hole, alright. Now we're going to cover a couple more foramen here. So if you look here, I'm going to try to angle this right here, there's a hole right here, this is called the foramen rotundum. It's called the foramen rotundum. And I'm going to go down a little bit more there's another one, it's a little more oval-shaped, this one is called the foramen ovale. Then I'm going to move it over here a little bit more laterally, it's right next to the foramen ovale, it's called the foramen spinosum. Okay this one's actually another one over here, you can see the foramen spinosum. It's a little bit better right there okay. That's a foramen spinosum right here, there's another hole that runs through here, that's actually called the foramen lacerum, the foramen lacerum, right there. Then there's another hole, I'm going to kind of turn it up so you guys can see it, it's called the carotid canal or the internal carotid artery runs through. So you've got the carotid canal over here and all this region right here kind of like this hill region is called the petrous region of the temporal bone on the backside here. We got the internal acoustic or auditory meatus right here, we got the internal acoustic or auditory meatus right there. Then if I work right here, this guy right there is actually called the jugular foramen. That's our jugular foramen and then this one is obviously the foramen magnum for the spinal cord, the brainstem in the spinal cord run out right. Alright, then if I'm going to scoop all these guys out, let's pretend I take an ice cream scoop again, so I scoop out this part here scoop out this part here. This is called the middle cranial fossa, just like this one is the anterior cranial fossa, this is the middle cranial fossa and this whole thing back here is the posterior cranial fossa. Alright, so that pretty much covers the structures that we're going to talk about inside the skull. Alright, so now we're going to do is going to focus on some of these bones over here. So if you look here, these are nasal bones, we have two of them. We already show you a little bit of the orbit, but I want to show you two more things of the orbits. So, in the orbit there is another slit-like structure because we had the superior orbital fissure. There's one that's actually going to be a little bit lower and that's called the inferior orbital fissure okay. We get a superior orbital fissure and then we got the inferior orbital fissure. The another structure I want to show you is this one right here and this is actually gonna be called the lacrimal fossa. Alright, so that's where the nasolacrimal duct that's actually going to kind of move through that area. Alright so that's the lacrimal fossa. Alright then, what I want to do is, if you look here there's a hole right underneath the foramen and it's called the infraorbital foramen right there. So infraorbital foramen. Alright, then we're going to come look at the nasal cavity. So, let me get you here inside the nasal cavity. So right here, actually you kind of look at this is that this is the maxillary bone right here. So all this right here, is the maxillary bone. These are the nasal bones but this pretty much is whole area right here is going to be the maxillary bone. So we look here, this is kind of like this little spiny part that's popping out there, you guys can see that, that is called the anterior nasal spine. Okay, there's this big bone though its own bone. And it's running all the way back here inside the nasal cavity. This one right here, it's called the vomer bone okay. Vomer bone. So it helps to be able to make up the nasal septum. I'm gonna kind of flip it up here and right in here, if you see this guy right there, that's actually called the perpendicular plate of the ethmoid bone. Now a little bit laterally to it, might not be able to see it that well, but these guys right here laterally to it. This right here is actually going to be called the middle nasal conchae. And this one over here on the other side of the middle nasal conchae, this guy right here is called the inferior nasal conchae. And then for your nasal conchaa right there. Okay so it kind of covers some of the structures inside of the nasal cavity. Alright ,now if we come down here and we look at the maxillary region. So this is going to be kind of like the alveolar processes, alveolar processes and you've got the alveolar margin right here, where the teeth are and the teeth sit in a little cavity called the gomphoses. it one the formsgomphoses joint. But the little alveolus is where the teeth actually sit in. We'll get into T's anatomy specifically later. Alright so again, that's going to cover that. Now I'm going to move down here to the mandible. You look at the mandible here, we got this part of the mandible right here. Where it looks like it's making like a little circle right, this is called the mandibular notch, it's called the mandibular notch right there. And then this right here is going to be called the coronoid process of the mandible, also this is the coronoid process. Then if you look here, that's part that's articulating with that mandibular fossa this is called the mandibular condyle. So these guys are here called mandibular condyles, okay. Now, if I make kind of like a square here, this is called the ramus, so it's the ramus of the mandible. And if I squeeze this thick part, this is where the bone is the thickest, so this is the body of the mandible, this part is the body of the mandible. Alright, sorry for my thumb guys. And then here is going to be the mental foramen right. So here's the mental foramen. So we've got the body of the mandible, you get the mental foramen, then you got the mandibular symphysis right here, okay. So you've got the mandibular synthesis. Then, if I come over and I actually try to get inside, I'm gonna flip this around here a little bit so we can see it. So inside here, we're actually going to have the mandibular foramina, mandibular foramina mandibular foramina. Right here, these guys. Alright so that covers these parts. Now we're going to kind of flip it under here and look at a couple structures inside here. So if you look here in the front, we've got the maxillary bone here in the front. Alright, so now if you look here we got this little hole right there, okay. This is called the incisive fossa, that right there is called the incisive fossa. Then we got over here, we still got them the palantine process. All this stuff right here is all the palatine process of maxillary bone. Don't confuse that with this part right here, this is actually the palatine bone. So the horizontal plate of the palantine bone and then moving here on the sides is the vertical plate or the perpendicular plate of the palatine bone. Alright, and then these guys right here, they look like little legs these guys are actually called the pterygoid processes of the sphenoid bone. Okay, that pretty much covers all the structures of the skull.