I ninja nerds in this video we're going to talk about the cranial nerves if you guys have watched our videos on the cranial nerves we covered each one individually in heavy detail so now what I want to do is get a nice little brief overview and I sort of recap of those nerves okay so let's go ahead and do that so in this video we're going to talk about each nerve individually again but we can have a little brief recap we're going to talk about where's the origin of the nerve what's the structures that are being supplied what are the fibers that it contains what's the function and then we're going to finish up with it's a sensory motor or both and we'll also talk a little bit about the actual clip a little bit of clinical anatomy via the what whole and the skull it's actually moving through okay let's go ahead and get started first one olfactory nerve where are you going to find these nerves well you guys remember we said that the mo tau Cecilia are going to be in the nasal cavity the roof of the nasal cavity so in the roof of the nasal cavities what we're going to find is nerve they also called the olfactory mucosa so we can find within the roof of the nasal cavity now what are the structures being supplied the nasal cavity it's that simple so the structures that are being supplied is mainly going to be the nasal cavity because if you remember it was located these actual olfactory receptors were located within that olfactory epithelium and the roof of the nasal cavity so it's supplying the nasal cavity now what type of fibers does it contain it's very special these fibers are so special and they're so visceral and they're taking information into the central nervous system so it's special visceral afgan fibers okay so it consists of what's called s v a fibers what does that stand for special visceral aftern fibers there's only two examples in the body of special difference one is going to be able factory and the other one is going to be the gustation okay the gustation pathway that we talked about alright so what is its function it's for olfaction but we're not going to say like that we're going to say a little bit more simple smell so it's picking up different types of odors so its function is for smell now now since that's the case whenever there is the odorants activating these olfactory receptors within the roof of the nasal cavity these SVA fibers are activated they're taking the smell to the central nervous system so because of that it's only taking sensory information so because of that we're going to circle here saying it's only going to be a sensory nerve now how does it get to the actual central nervous system by what hole in the skull isn't moving through it's moving through a bunch of different little holes within the ethmoid bone you know this what's called the olfactory foraminal which are a bunch of different holes within what's called the cribriform plate of the ethmoid bone so it's moving through the olfactory flam n'e of the cribriform plate of the ethmoid bone okay now olfactory nerves are found within the actual receptors are found within the roof of nasal cavity in the olfactory epithelium they're serving the nasal cavity they're picking up odorants okay so smell olfaction it's moving by the way of sv a special visceral affair and fibers there are sensory nerve they're moving through the olfactory foramen of the cribriform plate of the ethmoid bone and then eventually they're going to take this information to a special structure called the olfactory bulb okay so they're going to take it to an area right underneath the frontal lobe okay within what's called the olfactory group it's going to take it - it's called the olfactory bulb and then from here there's mitral cells and glomeruli on the olfactory tracks that will take it to different areas with inside of the brain okay to basically allow for us to be consciously aware of those different types of smells all right and we can take it to other different types of limbic nuclei the hypothalamus the hippocampus other different areas we discussed that sweet deal that's that bad boy now come over here through the optic nerve cranial nerve - okay origen very very similar origin is going to be found within what's called the retina okay so you're going to have what's called we actually made a video on the optic nerve right where we talk about the ganglion cells the axons of those ganglion cells those axons are the ganglion cells were located within the retina that is what's making up the optic nerve so what would you actually say the origin is it's technically and the retina okay what structures is applying it's supplying the eye but specifically it's picking up information from what the photoreceptors the rods the cones and even the ganglion cells which are containing the pigment called melanin so what structures are really really being supplied we should really be specific and say within the retina it's actually picking it up from photoreceptors so photoreceptors if we're really really being specific it actually be fast supplying the photoreceptors within the red rods cones and ganglion cells with the melanopsin what type of fibers is it these are very special and they're taking sensory information to the central nervous system so it's a special sensory act Behrendt okay so it's a special sis sensory afferent okay so again fibers are actually gonna originate in the retina they're supplying the photoreceptors rods cones in the ganglion cells with melanopsin they're carrying this information with a special sensory afferent fibers what's their function to allow for vision okay to allow for vision so since it's only carrying sensory information there's no muscles there's no glands being involved in this area it's primarily going to be a sensory nerve okay so a sensory nerve now as its taking this actual visual information what it's going to do is it's going to go through a whole within the skull what is that whole call that's actually located within the posterior part of the orbital cavity it is called the optic canal okay so it's going to move through the optic canal along with the ophthalmic artery and eventually these fibers will go to an area what's called the optic chiasma where some of the fibers will cross we discussed that in two detail then from there they'll eventually go to another area called the lateral geniculate nucleus where they'll be sent to the occipital lobe or the primary visual cortex is okay or the option of the sensation is a kind where what we see becomes a real okay all right that's that guy all right next one oculomotor nerve third cranial nerve this guy's really cool okay his origin because since he's actually very interesting his origin is located within the midbrain we're willing to talk about the main part we're not going to go into super neuroanatomy detail we're going to say just what part of the brainstem would you find to that for him he's going to be found in the midbrain his nucleus is located within the membrane two of the nuclei if you really wanted to know we already said that was at the level of the superior colliculus that's good enough okay now what type of structures is it supplying and supplying a lot of different extraocular muscles okay so let's go ahead and write down which ones I'll give you a lot of like acronym towards the end here of what it actually serves how you can get make it a little easier for yourself so one is going to be the superior rectus this is a big one in case a soupy rectus another one it's going to supply is what's called the Leavitt or palpebrae superioris okay another one that it's going to supply is called the inferior rectus another one is going to be the inferior oblique and another really important one is going to be the medial rectus but we're not done because you want to know what's really interesting the midbrain okay with the oculomotor nerve which is located within the midbrain it has two different types of fibers okay one type of fiber is going to be what's called G V I'm sorry G s e and another really really interesting one called g ve fibers the GS any fibers stand for general somatic events that's the somatic motor ones those are the ones that are going through the superior rectus levad or papaver superior or inferior rectus inferior oblique and medial rectus the gve is the parasympathetic fibers the editor Westfall nucleus which is taking that information to the ciliary ganglion which is doing what if you remember that was controlling the pupil and it was controlling the ciliary muscle basically the accomodation and the pupil constriction response so what else is really being supplied by this nerve then we could also say that it's supplying the pupil specifically the sphincter people--a and it's supplying another muscle called be silly eros okay okay so what is this function we're just going to say eye movement if we really want to be specific if it's controlling the superior I guess that's elevating the eye right if it's 11 or palpebrae superioris it's elevating the upper eyelid so you can say i movement and eyelid movement and it's controlling accommodation which is basically what Mesilla air is contracted change the shape of the lens and it controls pupils eyes so whenever it's these parasympathetic fibers the GV fibers innervate the pupil it caused the people to constrict when the silly areas contract it plays a role within near vision okay that's that guy okay and again if it's the inferior rectus he depresses the eyeball medially rotate super rectus elevates the eyeball medially rotate inferior oblique elevates the eyeball laterally rotate medial rectus immediately rotates and again it causes constriction the pupil and it causes the contraction of the ciliary to play a role with specifically within the lens by making the lens more accommodated for specifically certain types of vision and that vision is going to be near vision okay by making the lens more globular all right now what hole in the skull is this actual nerve going to be moving through oh before I do that what is it sensory motor or both okay well if you think about it it's really only carrying efferent fibers out since it's really only carrying the efferent fibers out it's not picking up any sensations so because of that this is primarily a motor nerve and it's moving through a hole within the skull if you guys remember we call it the superior I'm going to breathe he actually I can fit in an orbital fissure inside of the common 10-minutes ring if you remember okay sweet deal that one's done let's move on to the next guy the trochlear nerve this green one so it's coming here boom trochlear nerve where would it be located its origin the trochlear nerve is a very interesting nerve again it's located within the midbrain so it's located within the midbrain but if you remember we said it was at the level of the inferior colliculus we said that they actually cross coming from behind the midbrain and out the sides okay so now we know what's coming out of the midbrain what are some of the structures that supply its supplying a specific extra ocular eye muscle this muscle is called the superior oblique and the superior oblique is a very interesting muscle because whenever it contracts it actually depresses the eyeball and laterally rotates it okay I'm going to show you these on these models whenever we talk about our deuce and so we can put them all together okay what type of fibers is it carrying well it's really only having a muscle fiber and it's not it's not special its general so it's a general somatic okay you're supplying a skeletal muscle anything because the information is coming out of the central nervous system so therefore this is only going to be a motor neuron okay so it's a motor nerve function it's going to control eye movement okay and again what type of eye movement if we're being specific here superior oblique pulls the eyeball down so it depresses it and laterally rotate it now this nerve as it's moving and moving and moving what holds it actually moving through to get to the illiberal cavity it's moving through the same hole as the actual third cranial nerve instead it's running outside of the common tenderness ring but it's specifically moving through a hole called the superior orbital fissure and again it's moving outside of that common tendinous ring of the annulus of zin which was where the origin of the super rectus inferior rectus lateral rectus and medial rectus is okay and same thing here if we follow there nerves remember here is the third name the pink one it comes right here in the middle part of the midbrain it comes out on the inter binocular fossa the fourth nerve is coming out a little bit more on the lateral sides of the midbrain okay sweet deal that's that one now let's move on to the Beast this guy is a beast if you guys watch our trigeminal nerve video I can't thank you enough that one was a monster right but trigeminal nerve is a very very interesting nerve where are we going to find its origin its origin is primarily located within the pons right but remember we had that thing called a trigeminal ganglion okay but here's what's really interesting remember we said that the trigeminal nerve there was a couple different things in a different nuclei so it had what's called a median cephalic nucleus right I'm going to put knees in cephalic nucleus right that was located within the midbrain when I put MV for midbrain if you also remember it how it's called be the principal pontine nucleus if you remember that was in the pons and then it had that really really important one which was specifically called the spinal nucleus right and that one was located within the medulla and even a little bit within the spinal cord but then there was also another point of origin there remember we also had these worth a lot of the sensory fibers we also had the trigeminal motor nucleus that was also located primarily within the pause I'm going to put trigeminal motor nucleus which was primarily located within the pond and then it had that trigeminal ganglion which was located right on the actual petrous part of the temporal bone so that's good or not so remember reason cephalic nucleus is in the midbrain principle pontine nucleus is in the pons spinal nucleus of the trigeminal system was in the medulla and had a little extension into the spinal cord and the trigeminal motor nucleus is going to be in the pons if you want to remember the ganglion was located right there on the petrous part of the poor bone within the middle cranial fossa okay so what are the structures supply holy crap its supply so so so much to hit every single thing it's unbelievable we're going to really dumb down here okay so if we look it has one branch which is called an ophthalmic branch that's going to supply a lot of skin of the scalp okay the actual palpebral so the eyelids the conjunctiva even supply the actual skin of the scalp on the actual temporal side the forehead some of the actual parts of the top of the head up to the vertex so many different areas it can supply the actual skin is of around the ears so it can even supply the actual external ear it can even supply the skin around the actual chin it can supply the skin around the chin that skin around the cheeks get around the jaw oh my goodness you can supply so much we can even supply skin of what he can supply the skin of the jaw the chin even the nose he can even supply the actual skin of the nose he even can supply oh my goodness you can supply so much he can supply some of the internal cavities within the nasal cavity so you can supply the nasal cavity he can supply the oral cavity okay so you can even supply nasal cavity and oral cavity Wow but that's not even it yet so it can supply so much I can basically supply pretty much an entire face but another thing that's actually doing so it's applying the skin to the scalp the aisle is the conjunctiva the external air the skin of the jaw of the chin that knows the nasal cavity the oral cavity and even can give some actual supply to muscles what muscles okay these muscles that it's going to supply here are called the muscles of mastication the chewing muscles it also supplies two other muscles one of those is called the tensor tympani which if you guys remember it pulled on the malleus immediately tense the tympanic membrane to dampen some of the sounds from chewing another one was called the tensor villi palate and i which basically tents the actual soft palate to help in the process of the actual chilling to help to kind of pull up the pharynx a little bit right so these were some of the muscles that it supply and that was coming from the trigeminal motor nucleus in the pond okay so what are these this appliance applying so many different structures the skin the mucous membranes of what the scalp tyler's the conjunctiva the external ear the skin of the jaw the chin the nose the nasal cavity oral cavity many many different things it even can supply the orbital cavity so it can even supply the orbital cavity the nasopharynx even live with the French actor panic tube the tonsils so much it can even supply the tongue let's see if we can fit that in there we can even supply the tongue okay put it right here okay that's good enough it supplies a lot of different structures now what are the fibers okay since it supplies motor fibers you would think oh it's probably just the GSE no unfortunately since this actual the muscles that this guy serves the muscles of mastication tensor tympani tensor veli palatini these will actually derive from what's called the first four lineal arch so because of that it's going to contain special visceral efferent fibers also because it's picking up touch pain temperature from all and proprioception and pressure from all of these different areas it's going to have what's called general somatic efferent fibers so the touch pain temperature that supplies the skin of the scallop eyelids conjunctiva externally or skin of the jaw chin nose nasal cavity oral cavity tongue all those different things what's its function we already said it's to pick up sensations of touch pain temperature pressure and even mastication muscles so it's to be able to provide mastication muscles okay for chewing all right so a lot of different functions for this guy and then we know that it picks up sensations from all of these different areas and we know that supplies the muscles of mastication tensor temp and i-10 sorry about Palestine so it's not just sensory it's not just a motor it contains both fibers so this is containing both fibers then if that wasn't complicated enough it also these has three different branches okay we said that there's let's call it a V one branch which is the ophthalmic division of the two branch which is the actual maxillary division and a v3 branch which is the mandibular division each one of these branches goes through a different hole within the skull one I'm going to abbreviate them is the superior orbital fissure that's for the v1 got down the division okay and actually moves specifically most of the branches move through the super orbital fissure outside of the common 10-minutes ring v2 is actually going to be moving through a specific structure called the foramen Rotunda Mona put FR there and the three moves through what's called the foramen ovale it's called the infra temporal fossa then if you remember the motor fibers are only here I'll kind of put here of star if the motor fibers here only really running in v3 the mandibular branch but if you remember the sensory fibers are bringing the information into this big old structure here with the cell bodies of the remember that specifically we called the cell bodies of this actual nerve it was called the trigeminal ganglion and then from there can send into the medium cephalic nucleus the principal pawn tiny nucleus or down into the spinal nucleus okay that's good enough alright now we come to the last one over here the abducens nerve six cranial nerve this guys origin is located within the pons so it's a little bit more of the inferior pons if you guys remember we said that the facial nerve actually kind of runs around the abducens nerve so we can say we can find at the level of what's called the facial colliculus if you remember what structures this is applying it's very very simple it's only supplying one muscle within the orbital cavity called the actual lateral rectus so this is flying them also called the lateral rectus well several fibers is to have them well since it's applying the extraocular i'm also those are called g se5 or general somatic efferent fibers what is this function I'm moving particularly the lateral rectus causes lateral rotation of the IO AB duction of the i come but again we're just going to put here for right now to keep it very simple i movement but again keeping your minds very clearly that the lateral rectus does the lateral rotation or abduction of the eye then since it's only carrying motor fibers this is going to be a motor nerve now in reality the abducens there been some of the other nerves have minor minor sensory proprioceptive fibers but we're not going to consider that to be significant enough so we primarily consider him to be a motor nerve what hold is he running within the skull he runs in what's called the superior orbital fissure but inside of the common tenderness ring or the annulus of zen okay that's that guy now i told you i was going to give you a little acronym that's going to help out a little bit with being able to remember these extra ocular muscles in which nerve supplies which so easily remember let's actually write it up here you can remember lr6 so4 a tr3 how does this go lateral rectus supplies the sixth cranial nerve so if you're looking at the actual eyeball okay if you kind of want to get a little orientation of the muscles for example this is actually the lateral rectus this one right here is the inferior oblique this one right here is called the inferior rectus this one over on the backside is the medial rectus because this is the nasal side going into the board coming out from the board is the actual ear side right or the temple side whichever one you whatever you want to call it this right here is the superior rectus and it's one right above that is called the leavitt or palpebral superior doors and I'm abbreviating them okay because we already talked about them so lateral rectus is supplied by the six cranial nerve so this one you can remember o6k on earth okay sweet so4 superior bleak you can't really feed in this one that's why we have another diagram for you if we come down here to the bottom we're looking at the eye from the anterior view that one over there from the lateral view okay so specifically if you're looking at this from the anterior view just to give it a little orientation this is the medial side this is the lateral side so this would be medial rectus this would be inferior rectus this would be a lateral rectus and soupy rectus and then it just to get a little bit more inferior oblique right here and this bad boy right here is called the soup here oblique so the superior oblique is actually running through this little bony part called the trochlear it comes through the trochlear and attaches into the posterior and lateral aspect of the eyeball now because of that whenever it pulls it pulls downward and outward but again so4 superior bleak which supplies this one the fourth cranial nerve okay and then if you want since we're already down here might as well hit that ATR three what does that stand for all the rest is supplied by the third granular so which one's superior rectus what else inferior rectus inferior oblique okay and again who supplies lateral rectus just because since we're here six cranial nerve supplies lateral rectus here's remember lr6 to get the rest of them level palpebral superior yours and again superior rectus medial rectus inferior oblique and inferior rectus these are all supplied by the third cranial nerve okay sweet deal all right and again following this guy in if we fall this is cranial nerve as it's actually moving bit it's actually moving this leg is again its motor but if we wanted to see where it's actually coming out it's coming out right around this pons module of Junction okay so here's your pawns this is the medulla it's coming right around that actual sulcus or that junction between the two but the most medial part of it okay all right so sweet how will we recognize this one you can do it remember one one two three four five and six all right sweet so that covers everything on this side but we're going to keep going because remember there's actually 12 pairs of cranial nerves okay so now we have to hit the other parts of them okay so you would see the same thing on the other side here for one two and again three four five six now we're going to do is we're going to continue on with seven eight nine ten eleven twelve alright so let's go on to the next one facial nerve this is another beast okay origins of facial nerve you can actually primarily find this within the pons okay so primarily within the pons now remember this has many different nuclei for the facial nerve okay there's a bunch of different types of nuclei that we could talk about here we're not going to do that since we already discussed them in great detail so just remember for right now that the facial nerve is going to be located within the pons but there is many many nuclei okay so what are the structures that are going to be supplied by the facial nerve easy way to just remember it is it supplies the muscles of facial expression okay so muscles of facial expression that's the easy one to remember okay another one is it also is going to supply another little muscle inside of the middle ear cavity called the stapedius which is basically a muscle that plays a role whenever it contracts it actually helps to dampen some of the tapping of the state bees in an oval window to prevent excessive sounds right because of its damage like in Bell's palsy we talked about in close hyperacusis a very very sensitive miss to the sound waves okay but also if you remember this was the actual motor fibers it also supplied the digastric muscles - if you remember we talked about this it's supplied other muscles too we specifically said that it supplied the digastric muscles and it even supplied the actual stylohyoid okay okay so now what else it's also supplying specific glands its supplying specific glands what glands is in supply if you remember we've said that it's specifically supplying the lacrimal glands so it's supplying the lacrimal glands supplying the lacrimal glands what else does this apply it's also supplying another part here we also said it's applying the actual nasal glands okay so it's applying the nasal glands and we also said it's applying some little glands inside of the actual there on the palates of the Palatine glands what else is it doing it's picking up taste so it's picking up taste from the anterior two-thirds of the tongue so it's picking up taste so it's applying the anterior here 2/3 of tongue what else is there doing this guy that's so much right he's also getting also a little bit of supply to the actual tympanic membrane and even the ear so it's also supplying a little bit the ear a little bit of the tympanic membrane all right that should be good enough there right okay so what are the fibers in so again it supplies muscles of facial expression stapedius lacrimal glands basil and Palatine glands and here - there's a tongue and even the ear the fibers it has so many different fibers since it's applying the muscles of facial expression stapedius these are actually muscles that are derived from the second Forenza arch so because of that these are sv e fibers it supplies the lacrimal and the nasal and the Palatine glands so these are secrete a motor fibers or parasympathetic fibers so these are g v ii fibers it also is going to be picking up what taste from the anterior 2/3 of the tongue so gustation that is a special visceral afferent fibers and it's also going to supply touch pain temperature fibers to the tympanic membrane and the external ear that is g SI fibers so what is this function it controls the muscles of facial expression so all of those muscles that control your facial expression that's what it's doing so again we can say muscles of facial expression I'm not going to go through every single one of them but I remember the branches of it we actually talked about it we had the temporal we had the actual zygomatic we had the blue cool we had the market manipulated the cervical we talked about each branch it's also going to cause secretions so it's going to cause lacrimation which is production of tears it's going to cause nasal and Palantine gland mucus production right so it's going to cause secretion we're just going to put see creation here in general and it's going to pick up taste and it's also going to pick up touch pain temperature from the external ear and the tympanic membrane so it's also going to pick up touch pain and temperature from ear make it simple right okay so because of that it's picking up sensations from the tongue and from the ear external ear and it's providing secreto motor and muscle fibers okay so fibers that are going to the actual muscles so because it has sensory fibers and motor fibers so it contains both now this guy is a little tricky one because he actually moves through two different holes one hole where the main components of a facial nerve because there's actually two components the nervous intermediates and the facial enough proper facial nerve proper is the motor one it moves through two holes so we're going to just highlight this as two holes the first one it moves through is what's called the internal acoustic meatus this is the main one okay but then some of the fibers that are going to go to the muscles of facial expression and even the digastric right they're going to go to the digastric muscles and even a little the stylohyoid this is actually going to be specifically the stylo mastoid foramen okay all right that's that sweet deal that covers that guy that's the covers the facial nerve he is a beast now where is he actually coming if we follow him if we follow this guy the motor and sensory fibers that were moving through that actual those two holes they're going to come right here at the level of the pons medulla junction lateral to the abducens nerve and medial a little bit lower a medial and superior to this next nerve here what we're going to talk about called the vestibular cochlear nerve or cranial nerve 8 okay so now we go into the cranial nerve 8 vestibular cochlear nerve all right so this guy where are you going to find him he's really interesting because we'll talk about this one in more detail in the vestibular cochlea nerve that we know that we're actually going to find it with an upon some of the nuclei located within the pons the lower pond and some nuclear actually located within the actual medulla so because of that we say it's right on that pons medulla border or Junction okay so we really say that its origin is actually located what's called the pons medulla junction or border I'm going to put junction okay and again it's because you happen to call cochlear nuclei of the scapulae nuclei and because a lot of those guys are intersecting a right on that pons medulla area we just say it's our the pons medulla Junction for the origin so structures that are supplied it's mainly going to supply the inner ear but okay what part of the internet if we're standing for the vestibular portion because you know there's two branches of vestibular cochlear nerve the vestibular branch in the cochlear branch let's say that we do the vestibular branch first the vestibular branch supplies primarily what's called the vestibule and inside of the vestibule there's an area called the macula which is actually found within the utricle and the saccule and that's for static equilibrium right so vertical and horizontal acceleration or deceleration we also said that it's also going to supply another part right that are actually coming off the vestibule called the semicircular canals with inside of the semicircular canals so there's an area call in the semicircular canals which is actually consisting of the semicircular ducts which consists of the crista aunt Belarus and the Christian Polaris is for dynamic equilibrium or rotational acceleration right moving your head from side to side or spinning around okay and the last one is going to supply another structure this is the cochlea branch now the cochlea branch of the vestibular cochlear nerve supplies the cochlea okay so it supplies the cochlea specific part of the cochlea is what's called the cochlear duct that's where you actually have what's called the spiral organ of Corti and it's picking up sound waves okay so basically auditory sensations now what type of fibers are these because the vestibular cochlear nerve is so special and it's taking sensory information into the central nervous system it's a special sensory a parent okay so it's a special system sorry afferent fibers okay the only two special sensory afferent is going to be the optic and the vestibular cochlear special visceral effect is olfactory and good station what is its function if it's supplying the vestibule and the semicircular canals it's basically these are playing a role within your balance your equilibrium so we said vestibule where the macula is is for static equilibrium your static equilibrium maintaining your balance in your posture basically right and then for these semicircular canals right where the christen pilaris is this is for your dynamic equilibrium so for a dynamic equilibrium in a lot for your eye movements and actually there's a lot of eye movements a little what's called a vestibular ocular reflex we'll talk about that in the vestibular cochlear nerve all right and then another thing as the cochlea and cochlea is just for sound so this is picking up sound waves whatever you get when I'm talking to you guys through the camera right now you guys are hearing me because of the sound waves compressing on the different parts of the Cokely we're not going to go into detail on that now okay so that's its function static equilibrium dynamic equilibrium and sound will go into more detail in that actual individual nerve here's what's really weird though people are like oh it's only going to be sensory fibers that is true it's primarily a sensory nerve but there's really weird to something really where there is efferent fibers that can go to specific hair cells okay that can actually cause these hair cells to contract specifically we'll talk about them like the outer hair cells they contain proteins called preston that can actually contract and play a role within accentuate in what's called the bowing of the basilar membrane so because of that they do play do play a little bit of a motor role so I'm going to put down here that they're both but remember I'm going to asterisk this right here it's primarily a sensory nerve okay but it does have a ferent fibers that are going there to control contraction of what's called the outer hair cells which contain a protein called preston which can play a role within the upward bowing or downward bowing of the vasila membrane so it has some efferent fibers okay but again it's primarily a sensory nerve but just because of whatever's are in the literature I'm going to put down both alright now when it's moving these actual sensory fibers and motor fibres what hole is actually moving through within the skull there's a hole located within that petrus Pradas important called the internal acoustic meatus guess who else runs down that hole the facial nerve right so the facial nerve is also running in the same hole as the vestibular cochlea but again the facial nerve can come out 500 Master Freeman right and give some clothes supply again to that we said muscles of facial expression style Ohio in the digastric posterior belly we said same thing that is got he can move through the internal acoustic meatus and where did you go he'll take this information to right around the actual pons medulla Junction it depends on what branch if it's the vestibular branch I'll take it - it's called vestibular nuclei if he takes it to what's called the cochlear branch I'll take it to cochlear nuclei we'll talk about that individually in those videos all right sweet deal we did the vestibular cochlear F now let's go over here to glossopharyngeal nerve this guy's are really cool on too because his origin is primarily within the medulla okay so it's board units primarily with inside of the medulla oblongata right within the actual brainstem now this guy has many many nuclei also we discussed him in great detail many nuclei we're not going to go into every single nuclei we're going to say we loads located within the medulla of the brainstem the main nuclei what structures it does is apply it supplies a googol amount of structures to make it easy I'm going to write down the fibers and it's going to I'm going to correlate it with the structures that are supplied and then the functions are basically the same so it has what's called as the V fibers okay special visceral apparent I mean efferent fibers these are fibers that are going through one muscle just one muscle within the actual palate and within the pharynx area this muscle is called the stylopharyngeus okay so I'm going to put stylo Firenze yes it also has g v a fibrous general visceral advent fibers this one's interesting because it's taking touch pain temperature a lot of different types of sensations there's some sensations from the oral cavity specifically the posterior one-third of the tongue the tonsils the actual pharynx the soft palate and even a little bit of the actual nasal facts - right okay so this guy I'm part like the Friends of tympanic tube so because of that he's actually going to pick up he's going to supply like the pharynx soft palate tonsils and even the tongue another area that he supplies you get what's called GSA fibers and these GSA fibers are actually going to go to supply a part of the panic membrane okay some of the inner products in panic membrane and it might even give a little bit branches that go into the external ear okay so it can also supply the ear via diesel is called GSA fibers that's not it though it can even have another one called g-v ii fibers general visceral efferent fibers these are secreted motor fibers they go to what's called the otic ganglion right via the lesser petrosal nerve and we've said that this supplies the parotid gland so let's throw this one up here also the parotid gland okay and it even has other GBA fibers that I didn't mention here that I actually go to what's called the carotid sinus so I can actually pick up what's called up the baroreceptors we have baroreceptors and we also have chemo receptors within the carotid bodies and the carotid sinuses so it also can supply I'm going to put here carotid branch okay and even can go and supply sensory information with the vagus nerve via the fringe of plexus to supply some sensory fibers to the pharynx and even the soft palate also so when you talk about its function he does a heck of a lot he the stylopharyngeus can actually help to pull the pharynx upwards so one is you can actually uh elevate pharynx going to put elevate pharynx represented with the up arrow it also is going to pick up touch pain temperature for the ear because I'm going to put touch pain temp for ear and it's also going to pick up touch pain temperature from the actual soft palate the actual tonsils the tongue and even the pharynx so we can put here with it pharynx soft palate month with soft palate here tongue and what else ooh throughout another one special visceral afferent special pits are often are basically paste fibers so because it also supplies the tongue it also picks up taste from the posterior one third of the tongue and if you remember it also ted picks up an information from the carotid branches so it picks up information like what's called the partial pressure of oxygen the partial pressure of co2 or pH arterial wise and it also picks information up on our blood pressure so if our blood pressure is too high blood pressure is too low it can regulate that and send that information into the medulla between central certain of centers with inside of the medulla via the cardiac accelerating the cardiac inhibitory center and even the days unloader center all right so that should be good enough there for the gloss of friends in there for all of these different things okay so because it has gve fibers and sve fibers along with GV AGS asva these are the sensory this is the motor so it has sensory and motor therefore it is containing them next to the mixed nerve as both this guy if we follow him where all these sqa fibers sp-gda GSE AG v so many different things oMG right it moves through a specific hole within the skull okay this is called the jugular foramen a lot of different structures run within that same hole like the vagus in the accessory nerve okay we did that one let's do the vagus now okay holy correct knuckles there's a lot of these right so Vegas is very very interesting he's probably going to be one of the more intense ones so the origin of the vagus nerve is also within the medulla okay so this is also going to be found within the medulla oblongata and again this has many many different nuclei that we discussed in great detail in the individual video what are some of the structures that it supplies okay get ready so it can supply so many different things it can supply the pharynx it can supply the larynx it can supply the heart I'm not going to write down every single organ I'm going to put down a lot of thoracic and abdominal viscera okay that covers a lot of different areas so it can supply what's called the thoracic viscera and I'll mention them heart lungs and it can supply the abdominal viscera like what do I mean it can supply the actual stomach it can supply the esophagus it can supply the liver it can supply the gallbladder it can supply this spleen it can supply the pancreas again supply the kidneys many many different areas even the small intestine large intestine primarily the cecum a sending colon transverse colon but where did we say it stops it stops either at the splenic flexure and some literature says the route but two-thirds of the transverse colon okay tons of different areas with some drastic viscera what else is a supply it's also going to have supply that's going to go to the epiglottis if you remember we have what's called the epiglottis and a little bit of taste buds within the pharynx a little bit of a soft palate it's picking up that information we sense primarily from the epiglottis okay it also can supply the ear so we also said going to supply the ear the external ear and even a little bit the actual tympanic membrane many many different structures there now basically basically what kind of fibers will we have here okay it has gve fibers these are secreto motor fibers this is basically for the secretion and the contraction of a lot of smooth muscle structures okay so for example secretion could be from a lot of the actual secretions within the actual abdominal viscera from the GI tea all right so secretions of certain stomach acid secretion of during seven types of mucus within area contraction of the actual small small intestine or large intestine or stomach also it's also going to be controlling the taste around the epiglottis so that's xva fibers it's also going to be tick picking up touch pain temperature from the ear so that's going to have G s a fibers it's also going to be supplying the muscles of the pharynx and even the soft palate going to put that one in there soft palate this would actually be asked v e fibers and again this is because we said that the glossopharyngeal nerve also has s v fibers it's actually derived from the third French arch the vagus is derived from what's called the the fourth and the sixth for in charge so he's supplying so many different muscles in the parents on the soft palate and gbes VA g SI s ve it's also going to have specifically GVA fibers and that's because it also can supply the aortic arch supplies the aortic arch where there's what's called baroreceptors so it actually can pick up specifically certain types of changes in blood pressure and there's also what's called aortic bodies which are basically picking up differences in within the partial pressure of oxygen co2 and even the pH so what is this function holy goodness it can affect the heart so if we say this and basically put you through every single thing it can actually affect specifically many many different functions here's what I'm going to say to make it a lot easier I want you guys to remember this it is the main parasympathetic nerve main parasympathetic nerve I don't want to take forever to go through every single thing on this because it'll just take so long so why don't you remember is that 90% of the parasympathetic outflow is carried by the vagus nerve I'm going to mention there really briefly it can cause contractions of the pharynx right to help with a note of deglutition process wherever you're trying to swallow it can play a role within the lens contraction of the larynx to basically play a role within voice production or phonation it can actually affect the heart by trying to slow down the heart rate okay I can go to the thoracic viscera like the lungs to basically pick up certain types of sensations from the lungs or basically cause secretions or constriction of the bronchioles smooth muscle it can go to the abdominal viscera which is going to supply the esophagus for contractions it can cause the stomach to contract the intestines to contract they can cause secretion of responding secretions of the intestinal slots and substances it can affect the liver it can affect the pancreas so many different areas the gallbladder it can pick up taste from the epiglottis they can pick up touch pain temperature from the ear and even can supply to some of the soft palate muscles and it can pick up changes within the partial pressure of oxygen the partial pressure of co2 and the arterial pH so many think this guys you know they actually the vagus means vagabond he's a wanderer because he freakin wanders everywhere in the body okay because he's doing so much so because that right away don't even guess he supplies so much he's a mixed nerve okay now this guy if we follow him where is he moving through in the skull he moves to the same hole we said it'd be what ninth cranial nerve and other one called the 11th greener nerve he's moving through it's called the jugular foramen also okay we're going to fly through these bad boys cuz they're pretty simple accessory nerve where you going to find his nucleus the accessory herb is primarily located within the medulla he's actually a part of it has it specific to different parts we actually need to be very specific we're going to put cranial part here part of the actual brain stem this is actually coming from the medulla where like the nucleus ambiguus is but then we have an actual spinal component of the accessory nerve and this is coming from these cervical spinal cord specifically from we said a c1 to c5 from the lateral funicular fibers right okay cool what is the structure that it's applying simple sternocleidomastoid I'm going to put SCM and the trapezius and if you remember these basically plays a role with a nub you can play a role within flexion to the neck you can play a role with an ipsilateral flexion and contralateral rotation of the head trapezius elevates the scapula retracts the scapula helps to stabilize somebody actually joint their right the actual shoulder joint fibers it's primarily I'm going to only be going to now here's the thing I got to actually be more specific to since the accessory nerve is actually it has a cranial part within the medulla a lot of the fibers from the cranial part go with the vagus nerve so what I'm going to put here is I'm going to be I'm going to put here it's also a vagal component okay meaning that it can travel with the vagus nerve just apply a lot of the soft palate muscles than the pharynx okay so fiber is primarily we're mainly going to focus on these two okay but again it does have bagel components that can move to the fan channel soft palate the fibers is primarily going to be GSE fibers okay but because some of the actual fibers can go to the vagal components for the fans and the soft palate I'm going to star it though it can have some sve components it even has a little bit of proprioception too but we're not going to even consider that because it's so minut alright function again we said since it's to apply an external cloud I'll master in the trapezius these player role within like to the neck like for specifically in sternocleidomastoid flexion of the neck and again it could be flexion if see lateral flexion and it also can play within contralateral head rotation so we'll put in their contralateral head rotation and if it's the trapezius he does what he elevates scapula and he also does what he retracts the scapula so he elevates and retracts the scapula so their elevates and retracts scapula holy goodness right so because of that he's mainly a motor nerve okay because if he does go to the vago component so supply some of the actual muscles of the pharynx in the soft palate either way that's a motor nerve so he's not really having any sensory fibers it's primarily a motor nerve now if we follow this guy got to be very very kind of particular the cranial component alright specifically when he exits when he acts it's through from the actual medulla he moves through a hole within the skull called the jugular foramen so he'll move within a hole in the skull called the jugular foramen now here's the tricky part the spinal part from the cervical spinal cord like c1 to c5 it actually moves upwards and through the foramen magnum and then combines with some of the fibers from the actual cranial component the accessory nerve so remember two holes that this actual nerve combined is moving through one is the jugular foramen that's from the common foot here see for the cranial part the other one is going to be specifically for thee it's going to also move through the foramen magnum and this is going to be the spinal part but then I remember the spinal part fuses with the actual fibers or from the cranial part and move to the jugular foramen so both what the spinal component and the cervical I'm sorry the cranial component can move through the jugular foramen okay just so we're clear so spinal component moves up through the foramen magnum combines with some of the crane no fibers and moves out through the jugular framing sweet deal last one holy crap we're going to make it here guys hype will go also nerve where would it originate this guy is also going to be located within the medulla so the nuclei for the hypoglossal nerve is located within the module of the brainstem structures that supplies keep it very simple it supplies the extrinsic and intrinsic muscles of the tongue we already went through every single one of these in great detail we're not going to mention them again okay so now if you remember basically the function of all of these muscles they help the intrinsic muscle the tongue help to be able to change your shape of the tongue right so basically curl the tongue whereas the extrinsic help to be able to elevate the tongue to retract the tongue protract the tongue all that different stuff right so they played a role within that different types of activities so retraction protraction elevation depression of the tongue that was the extrinsic muscles of tongue so what type of fibers are these okay so these are going to be primarily G se5 errs general somatic efferent fibers what is the function we already said so changing the shape of the tongue so they can change the shape of the tongue or they can protract retract elevate and depress tongue okay now it does have a little bit of sensory fibers from the meninges but we don't consider that to be that significance almost insignificant so primarily it's not going to have any sensory fibers we consider to primarily be a motor nerve so because of that he is only going to be carrying motor fibres considerably alright so again hypoglossal origin of the medulla goes the extrinsic and intrinsic muscle the tongue the fibers are primarily GSE fibers and the muscles that uncontrol the shape of the tongue protraction retraction elevation and depression the tongue this nerve tint this Merv this nerve runs to a special hole within the skull right where the so occipital condyles are there's a hole right within the occipital condyles here and that hole is called the hypoglossal canal okay so moosa' a little hole in that area called the hypoglossal canal and just to finish it all off here to kind of get an idea here again we already did all of these so again this nerve right here would be facial nerve so cranial nerve seven this brown one right here is the vestibular cochlear nerve cranial nerve eight this purple nerve right here is going to be glossopharyngeal nerve cranial nerve nine this green one here is going to be the vagus nerve cranial nerve 10 this blue one here is the accessory nerve cranial nerve 11 and this red one right here is actually gonna be the hypoglossal nerve cranial nerve 12 and again going in order here you can kind of see that the glossopharyngeal nerve is superior to the vagus nerve the vagus nerve is going to be a little bit more superior to the cranial component of accessory nerve and the hypoglossal nerve is going to be medial to these guys located right on that let's member these are the pyramids pyramids pyramids olives olives it's going to be right on that actual sulcus between the pyramids and the olives are engineered so I just can't thank you guys enough for coming in and watching this video here and all the cranial nerves I know is a lot of tad bit long and I'm sorry for that but I want you guys to understand that what we're trying to accomplish here in engineered Sciences to make these things really really make sense and sometimes that requires getting into the nitty-gritty details so if you guys have watched all of the videos on all the cranial nerves I can't thank you enough and I want you guys to know that you guys are really really going to know it now and if you guys have gone over after learning all and brutal those brutal cranial nerves you guys hit the overview I really feel it and I guarantee it that you guys will really really understand the cranial nerves and have a strong base in it Ezra I really appreciate you guys sticking in there with me hanging in there with me throughout all these cranial nerves can't say thank you enough I hope it made sense I really do hope that you guys enjoyed it and if you guys did please hit the like button comment down the comment section and please subscribe our ninja nerds as always until next time