Skull Anatomy - The BEST way to remember every bone — Transcript

Full transcript

1. 0:00The hardest part of learning the anatomy of the  skull is visualizing how all of the bones fit
2. 0:04together three-dimensionally. So, in this video,  I’ll teach you how to identify all the bones from
3. 0:08a frontal, lateral, and inferior view. Then,  we’ll use the cadaver images from Anatomage,
4. 0:13the creator of the world’s first life-size virtual  dissection table, to see how all these bones,
5. 0:19like the ethmoid and the sphenoid bone, fit  together inside the skull. If you’re ready to take
6. 0:24the anatomy of the skull and get it to stick in  your brain long term, then I got you covered. So,
7. 0:30let’s jump to the whiteboard and get started. By  the way, as we go through the parts of the skull,
8. 0:35I have a free study guide. It has a notes section.  It has practice activities, questions to answer.
9. 0:40So, that free study guide, it’s linked in the  description in the pinned comment below. Check
10. 0:44that out if you think it would be helpful. So,  let’s start with the lateral view of the skull.
11. 0:49And there’s really two parts of the skull that  we need to know. There’s the neurocranium. So,
12. 0:54the neurocranium is going to be all the bones  that touch the brain, that encompass or surround
13. 0:58the brain and protect it. And then we’ve got the  viscerocranium, which I have here in pink. And
14. 1:02that’s going to be all the bones that make up  most of the face. I’m going to leave this kind
15. 1:06of faded background here so you can see where  these different bones connect. We’re going to
16. 1:10build these in one at a time, starting with the  frontal bone. The frontal bone is in the front
17. 1:14of the neurocranium, and it also will cover part  of the orbit. So, the orbit is like the bony area
18. 1:21around the eye. And so, the superior part of the  orbit right here is made up of the frontal bone.
19. 1:26The frontal bone is going to articulate with a  lot of other bones: the parietal bone right here,
20. 1:30the sphenoid bone right here, the zygomatic  bone, lacrimal bone, maxilla, and nasal bone. So,
21. 1:35lots of bones that it articulates with. We’re  going to learn all of those. If you didn’t catch
22. 1:39everything I just said there, that’s totally  fine. Let’s take a look at what that frontal
23. 1:43bone looks like in this model from Anatomage. And  so, we can see here, as we strip that away, there
24. 1:49is the frontal bone. We can see here this is the  coronal suture. We’ll label that in the diagram
25. 1:54in a second. The coronal plane is the same as the  frontal plane. It kind of goes like this. And so,
26. 1:59that suture is going to exist in that coronal  or frontal plane. So, we call that the coronal
27. 2:05suture. And you can see also that it makes up the  superior part of the orbit there as we build that
28. 2:11skeleton back in. Up next, we have the parietal  bone. The parietal bone is actually two bones,
29. 2:17and those are going to make up kind of the top  of the skull. Up here, you’ve got a left parietal
30. 2:21and a right parietal. We’ve got two sutures I want  to label. Now, the coronal suture that we already
31. 2:25talked about, and that’s going to be between the  frontal bone and the parietal bone. And you’ll see
32. 2:29it kind of like waves back and forth like this.  So, most sutures do that as these bones grow
33. 2:34together. We also have what’s called the sagittal  suture. So, the sagittal plane goes like this, and
34. 2:39that’s going to separate the two parietal bones.  So, we have the sagittal suture. I’ve got it
35. 2:44labeled right there, but it would be running along  the top of the skull in that midsagittal plane,
36. 2:49separating the left and the right parietal  bones. We can take a look at what that looks
37. 2:53like here in our model from Anatomage. So, this  is that sagittal suture, and you can see the left
38. 2:59parietal bone, the right parietal bone. Here’s  the occipital bone in the back. This is going
39. 3:04to be the lambdoid suture because it looks like a  lambda, like an upside-down Y. It’s a Greek letter
40. 3:09that kind of resembles an upside-down Y. And  so, as we go through here, we can see those two
41. 3:14parietal bones. There’s that coronal suture right  there. One thing that’s interesting, I think,
42. 3:18is that the temporal bone right there actually  overlaps the parietal bone in this region right in
43. 3:24there. We can see it. So, it’s kind of interesting  there. So, that’s going to be the parietal bones
44. 3:29of the skull. Up next, we have the occipital  bone. The occipital bone is going to be in the
45. 3:34very back of the skull. It also forms kind of the  base of the skull. And we’ve got that lambdoid
46. 3:38suture between the occipital bone and the parietal  bone. So, the occipital bone will look like this.
47. 3:44We see everything in blue here is the occipital  bone. We’ll see here it actually extends pretty
48. 3:49far anterior, or forward. This part right here  is actually going to articulate with the sphenoid
49. 3:54bone, which we’ll look at in a minute. The  sphenoid bone would be right here. And we’ve got
50. 3:57this big hole in the bottom of the occipital bone.  That’s the foramen magnum, Latin for big hole. And
51. 4:03that’s where the brainstem of the brain is going  to go down through there and form the spinal cord.
52. 4:08So, there is that occipital bone making up the  back of the neurocranium. All right, next we’re
53. 4:13going to have the temporal bone. And the temporal  bone is a very unique-looking bone. First of all,
54. 4:19though, we’ve got a suture. This is the squamous  suture. If you know a little bit of histology,
55. 4:23you know that squamous epithelial cells are  the flat epithelial cells. And so, squamous
56. 4:28just means flattened. And so, if you look at this  whole region right here, it is sort of flattened.
57. 4:33There’s a ridge right here. This is where the  temporalis muscle is going to originate. And so,
58. 4:37we have this flattened section right there.  That’s how I remember it’s the squamous suture
59. 4:41between the temporal bone and the parietal  bone. Now, let’s zoom in on this and label a
60. 4:46few particular structures in the temporal bone.  First of all, we’ve got the zygomatic process.
61. 4:51The zygomatic bone is your cheekbone, which we  haven’t labeled yet. This process right here,
62. 4:55along with the temporal process of the zygomatic  bone, that’s going to be this section right there.
63. 5:01Those form the zygomatic arch. You can feel the  zygomatic arch. Find your cheekbone and then just
64. 5:06go back from that, and you’ve got that ridge right  there. That’s your zygomatic arch, and it’s formed
65. 5:12right there between the temporal bone and the  zygomatic bone. Next, we have the styloid process.
66. 5:17We’ve got a few muscles that connect to that, like  the stylohyoid. Those muscles are going to help
67. 5:21with things like our tongue movements. And there’s  a hyoid bone that’s like underneath our jaw right
68. 5:25here. We can see that styloid sticking out right  there. We also have something called the external
69. 5:32acoustic meatus. This forms the auditory canal,  basically where sound is entering in our ear. So,
70. 5:37in this temporal bone picture here, your ear is  right in here. So, this external acoustic meatus,
71. 5:44that’s the hole in your ear that sound goes  in. Like I said, it’s the auditory canal. And
72. 5:48we’ve got one more thing I want to label on here,  which is the mandibular fossa. So, the mandible,
73. 5:53or your jawbone, is going to articulate with  the temporal bone. You may have heard of the
74. 5:57TMJ joint, the temporomandibular joint. It’s  going to be the joint between the mandible
75. 6:03right here and the temporal bone. So, it’s right  in there. Now, in the back of the mandible, we
76. 6:09have the mandibular condyles. The condyles right  there will insert into the mandibular fossa of the
77. 6:15temporal bone. And so, that joint can move like  this. Again, condyle fits into the fossa for that
78. 6:22temporomandibular joint. All right. Inside of that  auditory canal, that external acoustic meatus, and
79. 6:28that meatus would be right here, that’s the top  part of it, the bottom part of it, and inside that
80. 6:32middle ear, we’ve got the auditory ossicles. The  reason I have them in this video and this diagram
81. 6:37is because the auditory ossicles are bones.  They’re bones that are in the skull. We often
82. 6:41don’t think of them as skull bones exactly because  their function is very different. They’re not to
83. 6:45protect the brain or form the face or anything  like that. They’re about transmitting sound,
84. 6:50or the movements, the vibrations of the tympanic  membrane into the cochlea right here and then into
85. 6:55the nerve. But those auditory ossicles, there’s  three of them. There’s the malleus right here,
86. 7:01the incus right here, and the stapes. And so,  those are going to be the three smallest bones in
87. 7:06the body. And those are bones that are technically  part of the skull. If you want to know about the
88. 7:10ear and how the ear works, I’ve got a separate  video for that. So, now let’s take a look at
89. 7:13what this looks like in our model from Anatomage.  We have the external acoustic meatus right there.
90. 7:19There’s the styloid process, the zygomatic  process forming the zygomatic arch right here,
91. 7:24and we’ve got the mastoid process right there. And  then if I take away the rest of that, we can see
92. 7:30some internal parts of the temporal bone. Right  here is where the vestibulocochlear nerve is going
93. 7:34to exit. And of course, the temporal lobe of the  brain is going to sit right in there. All right.
94. 7:38Next, we’re going to label the sphenoid bone. Now,  the sphenoid bone, and then also the ethmoid bone
95. 7:44that we’ll take a look at later, I think those  are the two most difficult bones to visualize. So,
96. 7:48we’re going to spend a lot of time taking a look  at the different parts of the sphenoid bone. We’re
97. 7:52going to spend a lot of time visualizing that.  Before we do that, I want to label one more
98. 7:55suture. This is the sphenoparietal suture. They  didn’t come up with a clever name for it. They
99. 8:01just named it after the sphenoid bone and the  parietal bone. So, sphenoparietal suture right
100. 8:06there. Now let’s look at the sphenoid bone in 3D.  So, one thing I want to point out first of all is
101. 8:11we can see it in a couple spots. We can see the  orbital surface right here that’s behind the eye,
102. 8:17and then we’ve got the lateral surface that we  were just looking at in our diagram right here
103. 8:21on the side. And you can see they’re going to  be kind of connected kind of back behind this
104. 8:25frontal and zygomatic bone right there. And you  can see a couple holes in the back of the orbit.
105. 8:30This is going to be the optic canal, where your  optic nerve, where all the visual information
106. 8:34from your eye gets sent to the brain. And we also  have a couple orbital fissures, or these like long
107. 8:39openings like this. We’ve got the superior orbital  fissure right there, and that’s going to have more
108. 8:44nerves that are going to control eye movement. And  there’s some blood vessels that go through there
109. 8:48as well. And then we have the inferior orbital  fissure, which we can see right in there. Now,
110. 8:53I want to point out those fissures because right  here we have something called the lesser wing of
111. 8:57the sphenoid bone, and right here we have the  greater wing of the sphenoid bone. So, when I
112. 9:01strip away the rest of the bones here, we’ll see  and we’ll be able to label those. So, this is
113. 9:05going to be the lesser wing of the sphenoid bone,  and then everything else here is the greater wing
114. 9:10of the sphenoid bone. We also have these two  processes sticking down. These are going to be
115. 9:14the pterygoid plates. And so, this would be where  the pterygoid muscles, there are these muscles
116. 9:18underneath the chin here that help you to chew in  addition to the temporalis and the masseter. So,
117. 9:24that’s called the pterygoid process, and there’s  a medial and a lateral pterygoid plate as part of
118. 9:28that. And then if I spin this all the way around  back here, there’s this little opening right
119. 9:32here called the sella turcica. That’s actually  where your pituitary gland is going to sit. So,
120. 9:37the brain is here, and the pituitary gland kind of  hangs down and is protected by that sella turcica
121. 9:42right there. Sella turcica is actually Latin for  Turkish saddle. And I did not look up for this
122. 9:48video Turkish saddles and whether this looks like  a Turkish saddle, I don’t know, but that’s where
123. 9:52the Latin name comes from. I feel like there’s got  to be a story there. Let me know in the comments
124. 9:56if you know why it’s named that. So, there is our  sphenoid bone. It looks sort of like a butterfly
125. 10:02in the skull right there. And right in front of  it is going to be the ethmoid bone. We’ve got the
126. 10:07nose right in here. Behind the nose, we have the  ethmoid. And then behind the ethmoid, spanning the
127. 10:12whole length of the skull, the width of the skull,  is this butterfly-shaped bone called the sphenoid.
128. 10:18So, hopefully that’s helpful for you to visualize  that bone. All right, let’s label a few of those
129. 10:22structures on the sphenoid bone I just talked  about. We’ve got the greater wing, which is all
130. 10:25this stuff right here. We have the lesser wing,  which is this part right here. And of course,
131. 10:29that’s on either side of that superior orbital  fissure right there. This would be the greater
132. 10:34wing on this side. There’s a lesser wing and a  greater wing on both sides of the sphenoid bone.
133. 10:38We have the lateral surface right here. That’s  the part we saw. That’s where your temple is
134. 10:42right here. And we have the orbital surface right  here. Of course, we have a lateral surface here,
135. 10:46a lateral surface on the other side, an orbital  surface here, and then an orbital surface right
136. 10:50in there as well. We’re just looking kind of  at an angle. On the inferior side of this,
137. 10:54we have those pterygoid plates, the medial and the  lateral pterygoid plates. And then if we look at
138. 11:00the back of this, I wanted to label that sella  turcica right there, the Turkish saddle, or the
139. 11:04indentation that houses the pituitary gland. Now,  we’ve gone through a lot of structures already,
140. 11:09but I want to give you a chance to pause the  video and see if you can label all the sutures
141. 11:12and all the bones that we learned so far of the  neurocranium. And then now we’re going to go back
142. 11:17to it. I recommend, as you watch the video, to  pause here and there and to actually practice
143. 11:22trying to remember all of these structures. That’s  going to help you learn it a lot better. Next,
144. 11:25we have the zygomatic bone. These are  going to be your cheekbones. Zygomatic,
145. 11:29that’s the zygomatic region of the skull. And one  part of this that I want to label is the temporal
146. 11:34process of the zygomatic bone. That’s because  the zygomatic process of the temporal bone,
147. 11:40as well as this temporal process of the zygomatic  bone, together make up that zygomatic arch that
148. 11:45we already pointed out earlier, that  ridge behind your cheekbone. All right,
149. 11:49let’s take a look at that in 3D. And so, there is  the zygomatic bone. We’ve got the frontal process
150. 11:55connected to the frontal bone. We got here is  connected to the maxilla. We strip that bone away,
151. 12:01we can see that in 3D. And of course, there’s that  temporal process right there. All right. Next, we
152. 12:07have the maxilla, or the maxillary bones. There’s  actually two of them. They connect to the teeth
153. 12:12right there, the upper row of teeth. And this is  kind of the cornerstone bone of the viscerocranium
154. 12:17because pretty much every unmovable bone of the  face is going to articulate with the maxilla
155. 12:22somewhere. It articulates with the frontal bone  right here, the nasal bone, the lacrimal bone,
156. 12:27the ethmoid bone right there, the zygomatic bone,  as well as the palatine bone and the vomer, and
157. 12:32the ethmoid are the bones we haven’t labeled yet.  Of particular note is it has this frontal process
158. 12:36right here that actually goes up the side of the  nose, and it also forms the inferior part of the
159. 12:42orbit right there. Let’s take a look at them in  3D, and we can see that a little bit better. So,
160. 12:46here is the maxilla in blue. Here is the inferior  part of the orbit that it makes up. Here’s that
161. 12:51frontal process that goes all the way up to  the frontal bone. Here’s the main body of the
162. 12:55maxilla. And then there’s this ridge right there  that separates the right maxilla from the left
163. 13:01maxilla. It also makes up a little part of the  nasal septum right there, where it’s going to
164. 13:05connect to the vomer, and the ethmoid bone is  going to be in there as well. And so, we can
165. 13:09see this if we come back here and strip the rest  of that away. We’ve got the zygomatic process,
166. 13:14frontal process of the maxilla. This is called  the alveolar process, where it connects to all the
167. 13:18teeth. Particularly interesting, if you go back  to here, there’s this big empty area right there.
168. 13:22That’s the maxillary sinus. This is actually the  largest sinus that you have, is that maxillary
169. 13:27sinus. And I like this particular model here  that we have from Anatomage because we can see
170. 13:32all of the sinuses, I think. So, let me go back  to right here. This is where the sphenoid bone is,
171. 13:38so that’s the sphenoid sinus right there. We  have, right in here, you can see these kind
172. 13:44of smaller holes right there. That’s going to be  the ethmoid sinuses. So, that’s not one big sinus,
173. 13:48but a bunch of little pockets. And then we have a  frontal sinus. Let’s see if we can see the frontal
174. 13:53sinus here. I think we can see part of it kind  of right in there. That’s the frontal sinus. So,
175. 13:58we’ve got the frontal sinus, the ethmoid sinuses,  the sphenoid sinus, and if I rotate this around,
176. 14:04we can see the maxillary sinus right there. All  right, now I need to go blow my nose. I used to be
177. 14:10a lot sillier in my videos. Let me know if I need  to bring that back. Do you like my dumb jokes,
178. 14:13or should I just stick to the content? All right,  let’s jump back to our diagram. After the maxilla,
179. 14:17up next we have the mandible. And so, the mandible  is going to be the jawbone. It’s the one movable
180. 14:23bone of the skull. It will connect to the teeth,  the bottom row of teeth right there. Let’s take
181. 14:27a look at some of the parts of the mandible.  So, first we have the body of the mandible,
182. 14:31and then we have a ramus of the mandible on  either side. So, the ramus is going to be this
183. 14:35flat region right here that’s going to stick  upward from the body of the mandible. We have
184. 14:40a couple things we want to label. Here is that  mandibular condyle that’s going to articulate
185. 14:45with the mandibular fossa of the temporal  bone. This is going to form your TMJ joint,
186. 14:50or your temporomandibular joint. So, that’s  the mandibular condyle. And then we have the
187. 14:54coronoid process right here. That’s going to be  the insertion point for the temporalis muscle. So,
188. 15:00the origin of the temporalis and then that  coronoid process right there is going to be
189. 15:05the insertion. So, origin of the temporalis,  insertion of the temporalis, and that muscle
190. 15:11will just pull up on that coronoid process to  help us to chew. Of course, corona is going to
191. 15:15be Latin for crown. And so, this is kind of like  a little ridge on a crown of sorts. And then this
192. 15:20little foramen right here is the mental foramen.  Again, we’ve got lots of these little foramina,
193. 15:25these little holes throughout the skull. I’m not  labeling most of them. There’s lots of them. But
194. 15:29this whole chin part is the mental region  of the face. Because just think of, like,
195. 15:34when you’re thinking, you might do this. You’re  thinking very mentally. All right, so let’s take a
196. 15:38look at what that looks like in 3D. And so, there  is the mandible. We’ve got the coronoid process,
197. 15:45the mandibular condyles right there. Here’s the  ramus. Here’s the body. And one thing I want to
198. 15:50point out that I didn’t label on my diagram here  is there’s another foramen right there. That’s
199. 15:55the mandibular foramen. And if you’ve ever had  dental work done where they’ve had to numb the
200. 15:59lower half of your jaw, they actually insert  the needle into the back corner of your mouth
201. 16:03and inject the anesthetic back there. Why are they  doing it there and not closer to the teeth? Well,
202. 16:08that’s because the nerve that supplies most of  the feeling for your teeth is going to be going
203. 16:13through that mandibular foramen right there. So,  they’re actually targeting the nerve that goes
204. 16:18through that mandibular foramen. Super cool  whenever we can make a connection between the
205. 16:23real-life stuff that we experience and the anatomy  here. So, that is the mandible. Now, let’s go back
206. 16:29to our diagram here. We’ve got a few more bones  that we’re going to label. We’ve got the nasal
207. 16:32bones right there. It looks like it would just  be one bone forming the top part of your nose,
208. 16:37but it’s actually two bones. And we can see  that here in our three-dimensional view. We
209. 16:42see this little suture between the two nasal bones  right there. So, it’s two nasal bones. Of course,
210. 16:46it doesn’t make up the tip of your nose. That’s  going to be all cartilage right there. But this
211. 16:50ridge right there is going to be made up of that  nasal bone that we see right there. After the
212. 16:56nasal bone, we’ve got the lacrimal bone. Now,  your lacrimal glands are not on the inside part
213. 17:02of your nose right there. Your lacrimal glands are  more up here, kind of on either side of the orbit,
214. 17:07more superior and lateral. But your lacrimal duct,  or your tear duct, where it drains the tears out,
215. 17:13is going to be on the medial side right where  that lacrimal bone is right there. And that
216. 17:17Latin word lacrimal just means referring to  the tears, or in Spanish, like lágrimas. So,
217. 17:22just remember that lacrimal bone, where your tears  are right there. And we can see that lacrimal bone
218. 17:26in our 3D image here, just a pretty basic flat  bone on either side there. And again, where that
219. 17:33lacrimal gland is is going to be up in here, but  then where the tear ducts are are going to be more
220. 17:37on this medial side. Last but not least, we’ve  got to make a little space for this last bone,
221. 17:41and that’s the ethmoid bone. Again, the ethmoid  and the sphenoid are the hardest to visualize, but
222. 17:45I think what I’m going to do here is going to help  out a lot. We’re going to use the Anatomage images
223. 17:49for this, too. We can barely see that ethmoid bone  sticking out there in the back of the orbit. Let’s
224. 17:54take a look at what that looks like in 3D. So,  here we see that orbital surface of the ethmoid
225. 18:00bone. It’s on either side. If I go back to right  here, we can see a little bit of blue sticking out
226. 18:05right there. It’s actually going to form part of  the nasal septum back in there. Let’s strip away
227. 18:09the rest of the bones and see what this ethmoid  bone really looks like. Very interesting-shaped
228. 18:14bone right here. This is the perpendicular plate  that’s going to make up a lot of the nasal septum,
229. 18:19along with the vomer, which would be down in  here, and then part of the maxilla down in here.
230. 18:23Here is that orbital surface. That’s the surface  that we can see. And then at the top of it, really
231. 18:28interesting, and we’ve got this plate right here  that’s got all these little dots that you can kind
232. 18:32of see there. This is called the cribriform plate.  And the cribriform plate is where the olfactory
233. 18:37bulbs or your olfactory nerve is going to sit. And  there’s going to be these little fibers that stick
234. 18:42down through those holes into the nasal cavity  down here. And that’s where our sense of smell
235. 18:46is going to be detected. We also have, if we kind  of move over to here, we’ve got the the middle and
236. 18:51superior nasal conchae right there. The inferior  nasal concha will be down here, but we don’t see
237. 18:56it on this bone because it’s its own bone. The  inferior nasal concha is a separate bone from
238. 19:00the ethmoid bone. And then this ridge right here  sticking up is called the crista galli. The brain
239. 19:05is going to be right here, kind of the front part  of the brain. This is considered a neurocranial
240. 19:10bone because it does touch the brain in this top  surface right here. So that’s that ethmoid bone.
241. 19:15And of course we have the ethmoid sinuses are  going to be in here as well. If we go back to
242. 19:19here, we build this back in. This is the sphenoid  bone right behind it. Of course, the nasal bone
243. 19:25right in front of it. So it really sits right  behind your nose. Now all the structures of the
244. 19:29ethmoid bone, I’m going to label those on an image  when we get to the frontal view in a little bit.
245. 19:33Not pictured on here are a few bones, the vomer,  the palatine bones that are going to make up part
246. 19:38of your hard palate back there, and the inferior  nasal concha. We’ll see those on the other views
247. 19:43that we have. So there’s our completed diagram.  Again, this is a great time to pause the video,
248. 19:47see if you can name all the structures that  we’ve done so far. Now we’re going to take
249. 19:50a look at a frontal view. We’re going to go a  little bit quicker because in the lateral view
250. 19:54I was introducing all the bones for the first  time. Again, we’ve got the neurocranium and the
251. 19:58viscerocranium. The neurocranium that protects the  brain. The viscerocranium that forms most of the
252. 20:02face. And we’re going to build those in one bone  at a time, starting with the frontal bone. The
253. 20:06frontal bone, we’ve got the supraorbital foramen  right there. It just means above the orbit. So,
254. 20:12supraorbital foramen. And the frontal bone forms  part of the orbit, the superior part of the orbit,
255. 20:18right there. We have the parietal bones, which we  can see just a little sliver of right there. And
256. 20:22we also have the temporal bones, which we can see  just a little section of right there. And next we
257. 20:27have the sphenoid bone. And so here we can see a  lot of parts of the sphenoid bone. We’ve got the
258. 20:32lateral surface as well as the orbital surface.  Here we have the superior orbital fissure. There’s
259. 20:38the optic canal where the optic nerve comes  through. And then this right here is this lesser
260. 20:43wing of the sphenoid bone. This surface and this  surface are going to make up the greater wing of
261. 20:48the sphenoid bone. Take a look at that in 3D. Once  again, greater wing. So, we’ve got the orbital
262. 20:54surface, the lateral surface, the lesser wing  right there, and the greater wing on that side.
263. 20:59So, again, there’s the sphenoid bone. Probably  the most important one to be able to visualize
264. 21:03three-dimensionally. And I want to show on my  skull model as well what this looks like. So,
265. 21:07if I slide back here, there is the sella turcica  where that pituitary gland will live. And you can
266. 21:13kind of see the outline of that sphenoid bone  actually goes all the way up into here as well.
267. 21:18This right here is where the optic canal and the  superior orbital fissure are going to be. So,
268. 21:24sella turcica, and then here the optic canal and  superior orbital fissure will be right in there.
269. 21:28Up next we have the zygomatic bones. So those  are the cheekbones on either side. We have the
270. 21:33maxilla. Again, we’ve got the inferior orbital  surface is made of the maxilla. We’ve got the
271. 21:39frontal process of the maxilla right there. This  is going to be the infraorbital foramen. We have
272. 21:43the supraorbital and infraorbital foramen.  And we’ve got the mandible down here. Again,
273. 21:48we’ve got the coronoid process that connects  to the temporalis muscle. And we’ve got the
274. 21:53mandibular condyles, which will articulate in that  temporomandibular joint. All right, let’s get that
275. 21:57mandible back up there. All right. Next, I’m going  to go through the bones that make up this orbit
276. 22:02right here. So, this is the nasal bones. We’ve got  one on either side. And I use this as an acronym
277. 22:07to help me remember the bones as we go from the  medial side all the way over to the lateral side
278. 22:14across the orbit. I find these bones a little bit  hard to identify which is which because there’s
279. 22:18a bunch of just small sections of bone as we go  back. And so I use the acronym national medical
280. 22:23licensure exams. Do you remember this? Now that’s  not a real exam. In the United States we have the
281. 22:29USMLE, but that doesn’t work for the acronym here.  So, I just remember the national medical licensure
282. 22:34exams. All these doctors everywhere have to have  to take the national medical licensure exams.
283. 22:39And so, I’m going to go through these bones and  follow along with that acronym as we go. So, we
284. 22:44have the nasal bone right here. Up next, we have  the maxilla. Again, I’m going to label it again
285. 22:48right here for now just because it’s the next one  in the acronym and because we got that frontal
286. 22:52process. So, national medical, nasal maxilla.  Then, after that, we have the lacrimal bone. So,
287. 22:58national medical licensure, lacrimal. And then  after that we’ve got the ethmoid bone. So we have
288. 23:04the national medical licensure exam for ethmoid.  And then we’ll have the sphenoid bone right there.
289. 23:11That’s the S in exams. So sphenoid, and then  the zygomatic bone. So nasal, maxilla, lacrimal,
290. 23:19ethmoid, sphenoid, and zygomatic. National medical  licensure exams. Hopefully that’s helpful. If you
291. 23:26have some other acronym feel free to use that.  Now I do want to talk a little bit more about the
292. 23:30ethmoid bone. We can see the perpendicular plate  right here as well as the middle and superior
293. 23:35nasal conchae will be right in there. And then  we got the orbital surface of that ethmoid bone.
294. 23:40So I’m going to show this in 3D one more time.  We see the orbital surface right there. And if
295. 23:45I pull this back, we’ve got that perpendicular  plate. We’ve got the superior and middle nasal
296. 23:51concha. Pulling back to right here, we’ve got the  cribriform plate and the crista galli right there.
297. 23:56So we’ll label them on this diagram. The orbital  surface, the perpendicular plate that makes up
298. 24:01part of the nasal septum, the superior and middle  nasal concha will be right in there. And we’ve
299. 24:06got the crista galli, this ridge that sticks up  into where the brain is right there. And then
300. 24:10the cribriform plate where the olfactory bulbs are  going to sit and the olfactory fibers are going to
301. 24:16go down into that nasal cavity. In this diagram,  we can see the cribriform plate is going to be
302. 24:21right there. There’s the olfactory bulb right  there. And you can see those olfactory nerves
303. 24:25that are sticking down into the nasal cavity. Of  course, the nasal cavity isn’t just like this big
304. 24:29open hollow region. There’s the concha in there.  It’s not quite as hollow as the diagram makes it
305. 24:34look. And then I want to show that cribriform  plate again. So if I go right in there,
306. 24:37there’s the cribriform plate and the crista galli  right there. So sphenoid, frontal bones, ethmoid
307. 24:44bone right there. Next we have the inferior nasal  concha. The inferior nasal concha, there’s one on
308. 24:49either side. So, it’s two different bones and they  are pretty small bones. Uh, we’ll see those here.
309. 24:55We can see them right there on either side of  the nasal cavity. One thing I want to point out,
310. 24:59you look, the nose is a little crooked here.  Why are the why are the models from Anatomage
311. 25:03a little bit crooked here and there? Well, these  are taken from actual scanned cadavers. This is
312. 25:08not like an idealized version of what all these  structures look like. We’re looking at what these
313. 25:12structures look like in an actual person. So, the  nose is a little bit crooked. One’s a little bit
314. 25:17higher than the other because we’re looking at an  actual human here, which is really cool. And so
315. 25:20we see those inferior nasal concha right there. Of  course, the nasal concha will help swirl the air,
316. 25:25warm up the air whenever we breathe in through  our nose. All right, up next we have the vomer. We
317. 25:30just see a little section right there. It’s going  to form part of the nasal septum in addition to
318. 25:34this ridge of the maxilla, the vomer, and then the  perpendicular plate of the ethmoid bone. So let’s
319. 25:39take a look at what that looks like in 3D. We see  that in blue. And one thing I want to point out,
320. 25:44it’s mostly this flat bone that kind of extends  back, makes up part of the nasal septum. But
321. 25:48in the back part of it, we see these two wings  sticking out. And when we look at the inferior
322. 25:52view of the vomer, we’ll see those wings sticking  out. So I want to point those out here. So that is
323. 25:57our completed diagram of the frontal view.  Not pictured, we did not have the palatine
324. 26:02bones and we did not have the occipital bone.  And so if you’d like to, now is a great time
325. 26:06to pause the video, see if you can name all of  those bones on this frontal view of the skull.
326. 26:12But we’re going to continue on with the video  for now. And now we’re going to take a look at
327. 26:16the inferior view of the skull. I really love this  diagram. It’s it’s very visually interesting. It
328. 26:21looks like something maybe out of a horror movie  as well. I just think it looks really cool. Also,
329. 26:25I don’t have the mandible shown on this particular  view. So, we’ve removed the mandible, which would
330. 26:29be right in here. Again, we have this divided  up into the viscerocranium right here and the
331. 26:34neurocranium. And this is going to be the anterior  side. This is going to be the posterior side. So,
332. 26:38let’s build this in one bone at a time. We’re  going to go quickly through these first bones
333. 26:41that are not quite as interesting from this view,  but we do have the zygomatic bones up there on the
334. 26:46anterior side. We got the frontal bone. We can  kind of barely see it right there. And the first
335. 26:50kind of interesting one I want to label some  stuff on is the is the almost call this the
336. 26:54triceratops bone because it really does look like  a triceratops. We got the face right there. We got
337. 26:58the two like like two horns of the triceratops.  Am I am I is anybody agreeing with me here? Does
338. 27:03that that looks like two triceratops like facing  each other? Let me know in the comments if you
339. 27:06think that’s looks like that. Anyway, it’s the  temporal bone. And let’s zoom in on that. I want
340. 27:10to just label these structures again. Again, we’ve  got the zygomatic process of the zygomatic arch.
341. 27:14We have that styloid process right here. We  have the mastoid process right there where the
342. 27:19mass muscle connects to. We have the external  acoustic meatus that forms your auditory canal
343. 27:25right there. And we’ve got the mandibular fossa  where the TMJ joint will be. We’ve got a couple
344. 27:29openings right here and right there. This  one, I believe, is the stylomastoid foramen,
345. 27:34and we’ve got the carotid canal, but I don’t  have those labeled on the diagram. Up next we
346. 27:38have the parietal bones and you can see them kind  of sticking out right there and right there just a
347. 27:43little bit from this view. And then of course we  have the occipital bone which is very prominent
348. 27:47in this inferior view. I want to label a couple  structures on there. We have the foramen magnum
349. 27:52we talked about where the brainstem and spinal  cord will exit from the skull. And then we have
350. 27:56the occipital condyles right here and right there.  Those condyles are going to be the parts of the
351. 28:02occipital bone, or the parts of the skull,  that will articulate with the top vertebrae,
352. 28:06the atlas. So on my skull right here, you can  see the occipital condyles right there and
353. 28:11right there. And those are going to articulate  with the atlas, the C1 vertebrae. All right,
354. 28:17going back to our diagram here. Let’s label some  of those facial bones. We’ve got the maxilla right
355. 28:21there. And the maxilla is going to make up most of  the hard palate, or the roof of your mouth. It’s
356. 28:26the anterior part of that, the anterior maybe like  2/3 of the palate. And then the posterior third of
357. 28:32that hard palate is the palatine bone. Now the  palatine bone we have not visualized in 3D yet.
358. 28:37So let’s take a look at what that bone looks like  right here. So we have in blue that palatine bone
359. 28:41and it’s going to have a process sticking out on  either side right there. This is going to be the
360. 28:45horizontal part of the palatine bone and then we  have the perpendicular part of the palatine bones
361. 28:52that stick up in here and they make kind of the  back side walls of the nasal cavity. Those are the
362. 28:57palatine bones. And just remember, you’ve got the  horizontal part and the vertical or perpendicular
363. 29:02parts of the palatine bone. And those are going  to make up the posterior part of your hard palate,
364. 29:07which is also made up of the maxilla right  there. Those are the palatine bones. Now,
365. 29:11there are two of them. You can see a little ridge  right there where they’ve grown together. Those
366. 29:15are the palatine bones. All right. Two more  bones to label on here. We’ve got the vomer,
367. 29:19which we can see right there. Again, we’ve got  kind of the ridge of the vomer, and then the
368. 29:23two wings of the vomer. And I’ll point those out  just real quick here. Again, we’ve got those two
369. 29:27wings and that’s what we’re seeing, the ridge and  then the two wings of the vomer. Those are the two
370. 29:32wings on either side right there. Finally, we’ve  got the sphenoid bone. Again, the sphenoid bone,
371. 29:37that’s that butterfly-shaped bone right here. It’s  a little bit hard to see from this inferior part,
372. 29:41but this right here is going to be the pterygoid  process. Those two plates that stick down off the
373. 29:48bottom of the sphenoid bone. So, I’ll label those  there, the pterygoid process. We can see those
374. 29:53pterygoid processes pretty well in my skull right  here. We’ve got the pterygoid processes right in
375. 29:58there. We got the palatine bone down there.  And this is the nasal septum, which would be
376. 30:02made up of like the vomer right there and the  ethmoid bone as well. To study or not to study,
377. 30:09that is the question. Anyway, I don’t know  Shakespeare very well. Let’s continue on. So,
378. 30:12not pictured here is the ethmoid, the lacrimal,  the nasal, the inferior nasal concha, and the
379. 30:17mandible, basically most of those like kind of  facial bones that we can’t see from this inferior
380. 30:22part. So there’s our completed inferior diagram.  Not that it’s worse than the others. It’s inferior
381. 30:27from the bottom. Now we have covered a lot of  stuff. So like I said, I have a study guide that
382. 30:32goes with this. It’s free. You can find that link  in the description. That’s going to give you a lot
383. 30:36of ways to practice all of this information so you  can learn it really well. And before we go, these
384. 30:40are some color-coded images provided by Anatomage.  And all three diagrams are color-coded the same.
385. 30:46So, another chance to pause the video, see if you  can identify all of these bones in these diagrams,
386. 30:51and I’m going to go and go through them. One  last review of this before we finish. So,
387. 30:55we’ve got the frontal bone right here and right  there. We’ve got the parietal bones right there.
388. 31:00You see the right and the left parietal bones.  You can see them right there as well. We’ve got
389. 31:04the occipital bone back here, which we can also  see right back here, and the foramen magnum right
390. 31:09there. The occipital condyles right there. We  have the temporal bone right here and we can see
391. 31:13all the processes sticking off of the temporal  bone. We see that temporal bone right there.
392. 31:18There’s that styloid process sticking off, the  external acoustic meatus right there. Of course,
393. 31:22we’ve got the sphenoid bone, the lateral surface  there, the orbital surface of the sphenoid bone,
394. 31:26the greater wing, the lesser wing, and we’ve  got the inferior part of the sphenoid bone with
395. 31:31those pterygoid processes sticking down. We have  the zygomatic cheekbones right there. We can see
396. 31:35them right there as well as well as right here.  We’ve got the maxilla, kind of the cornerstone of
397. 31:40this. It extends all the way up to the frontal  bone right there. There’s the maxilla. There’s
398. 31:44two bones, one on either side. Of course, we’ve  got the mandible right here and right here. The
399. 31:49coronoid process, the mandibular condyle, which  connects to the mandibular fossa of the TMJ joint,
400. 31:54through the mandible right there. And of course,  right here, we’ve got the nasal bone right here
401. 31:59and right there. We’ve got the lacrimal bone in  pink right there. And right there, we’ve got the
402. 32:04ethmoid bone. You can see a little bit right there  and right here. The the nasal concha right there,
403. 32:09the perpendicular plate. We can see the ethmoid  bone a little bit in this view. We’ve got the
404. 32:13palatine bone right there and we’ve got the vomer  right here with the two wings, and we can see the
405. 32:18vomer right there as well. And then here we  have the inferior nasal concha, which I think
406. 32:22we can actually see a little bit right there. So  hopefully that was helpful and you learned a lot
407. 32:26about the bones of the skull. Special thanks  again to Anatomage. This video would be very
408. 32:30different without all of the 3D cadaver images  that they provided for us to really visualize
409. 32:35these structures three-dimensionally, especially  the ethmoid and sphenoid bone. Like it’s just so
410. 32:39important to be able to visualize spatially  where all these are located. So check out the
411. 32:43link in the description for more information about  Anatomage and their life-size virtual dissection
412. 32:48table and their tablets that they have. And all  of their models are scanned from actual cadavers.
413. 32:53Very cool stuff. So check those out in the link  in the description below. Special thanks to
414. 32:57everybody who supports this channel, whether it’s  on Patreon or YouTube channel memberships or part
415. 33:01of my memory lab program. Um, there’s some names  on the screen. So thank you all for supporting the
416. 33:05channel. And if you’re learning anatomy and you  want more help from me beyond just the YouTube
417. 33:09videos that I have posted for free, I’ve got  some paid products such as my A&P study cards,
418. 33:14my comprehensive guides for each system, and  again, I’ve got that free study guide for
419. 33:19this video down below. And if you’re ready to  move on to the next topic in your study of the
420. 33:24skeletal system, here is my full skeletal system  playlist. It’s got all my skeletal system videos,
421. 33:29so you can kind of binge those if you need  to, if you’re cramming for a skeletal system
422. 33:33test or something. Hopefully this video was  helpful and I’ll see you in the next one.