0:00 Hello, in this video we're gonna look at the, well we're gonna revise the cran 0:10 ial nerves 0:10 and then we're going to look at where the cranial nerves exits the skull. 0:17 So here is the inferior view of the brain and we're looking at the olfactory 0:21 nerve here, 0:22 cranial nerve number one, the optic nerve. 0:27 Here is your ocular motoral, number three, number four is your trochlea, five 0:31 is trigeminal, 0:33 six is your abducent, seven is your facial, eight is your vestibular cochlear 0:40 nerve, nine 0:40 is your glossopharyngeal nerve, ten is your vagus nerve, eleven is your 0:47 accessory nerve, 0:48 and twelve is your hypoglossal nerve. 0:52 If you want to know the function of these cranial nerves, I have a video on the 0:56 , an overview 0:57 video on the functions of the cranial nerves and I'll provide a link to that. 1:02 Now let us look at where these cranial nerves exits through the skull. 1:10 And so to do that we have to look at the base of the skull. 1:14 So this is a superior view of our skull and we're looking at it from 1:20 essentially the top 1:21 and we're looking down and we've cut it across, cut it. 1:25 So we're looking inside the skull, the base. 1:29 So let's begin with cranial nerve number one, which is your olfactory nerve. 1:33 Now your olfactory nerve, it sits on a cribiform plate of the ethmoid bone and 1:40 its function 1:41 is for smell. 1:43 Your optic nerve, your cranial nerve number two, it exits through what's known 1:46 as the 1:47 optic canal. 1:49 Your ocular motor nerve, the trucklier nerve and your obducens nerve, which are 1:54 your 1:55 cranial nerves number three, four and six. 2:00 These nerves are the nerves responsible for the movement of the eyeball. 2:04 They exit through the same hole known as the superior orbital fissure. 2:12 So we missed cranial nerve number five, which was your trigeminal nerve. 2:17 And there are three big branches of your trigeminal, your V1, V2 and V3 2:22 branches of your trigeminal. 2:25 While your trigeminal, the V1 branch of your trigeminal, it actually exits also 2:32 through 2:32 the superior orbital fissure. 2:35 What's important to know also is that all these nerves that exit through the 2:39 superior 2:39 orbital fissure, which are your oculomotor, trucklier, abducent and your trigem 2:46 inal V1 2:47 branch, also known as the ophthalmic branch, they actually pass through part of 2:52 the brain 2:53 known as the cavernous sinus. 2:54 And the cavernous sinus is just a collection of essentially venous system, a 2:59 venous system. 3:00 And problems in this cavernous sinus, such as an infection, can cause 3:06 complications associated 3:07 with these cranial nerves. 3:09 So I hope that made sense anyway. 3:11 So let's look at the other branches of the trigeminal nerve, the V2 and the V3 3:15 and where 3:16 they pass through. 3:17 So the V2 branch, it passes through the foramen rotundum. 3:21 The V3 branch, also known as the mandibular branch, exits through the foramen 3:27 ovale. 3:28 Cranial nerve number seven is your facial nerve. 3:31 And your facial nerve exits through the internal acoustic meatus. 3:34 But there's also another nerve that exits through here, which is the cranial 3:38 nerve number 3:39 eight. 3:40 You have vestibular cochlear nerve. 3:42 So the facial and vestibular cochlear nerve exits through the internal acoustic 3:48 meatus. 3:49 The next set of nerves, cranial nerves, exits through also the same hole. 3:54 So these are your glossopharyngeal cranial nerve number nine, vagus cranial 3:58 nerve number 3:59 ten and your accessory spinal nerve, cranial nerve number eleven. 4:03 They exit through the jugular foramen. 4:08 Then you have the last cranial nerve, which is your hypoglossal nerve, which is 4:11 your cranial 4:12 nerve number twelve. 4:13 And this exits through the hypoglossal canal. 4:17 Quite easy to remember. 4:20 Just to finish everything off, this big hole here, this is your foramen magnum. 4:25 This is where essentially the brainstem spinal cord passes through. 4:31 And interestingly enough, your spinal accessory nerve actually loops down 4:37 through this through 4:38 this foramen magnum before exiting up, back up at the jugular foramen. 4:45 So the spinal accessory nerve is an exception in terms of how it exits, the 4:51 skull. 4:52 I hope you enjoyed this video. 4:54 Thank you for watching. 4:55 Again, if you want to learn more about the cranial nerves, I'll have the link.
