iein in generic to this video we're going to talk about the cervical plexus the simple plexus is extremely important because it's going to supply a lot of structures of the head the neck and even some other muscles that we'll talk about now we're going to talk about in a series of videos are going to talk about the cervical the brachial the lumbar and the sacral plexus before we do that when you start going in all the detail the diagrams of it let's actually just quickly look at an actual anterior view of the spinal cord interview the spinal cord so if you look here and the anterior view the spinal cord this is actually the spinal cord right here so we're looking at the anterior view up here these are going to be your cerebellum medulla pons right now out of the anterior gray Horn of the spinal cord out of the anterior gray Horn of the spinal cord so let's say for example this is our anterior grey horn right here out of the anterior grey Horn of the spinal cord you'll have these reutlitz coming out right you'll have these rootlets coming on you'll also have some things coming from the posterior aspect right and they'll come together and they'll make this nerve right so you're going to have these posterior and anterior reutlitz that are coming out now these are going to make a spinal nerve but you know it's important these are paired so if there's actually on this side so let's say that this is the left side let's say this is the right side you'll also have that same spinal nerve coming from the opposite side here on this side too so again let's say that this is right and let's say that this is the left side right this would be a spinal nerve and this would be a spinal nerve on the other side now this is important because when we take the spinal cord we're going to separate it into a couple different segments or regions so let's say for example we take this and we have a green section here so let's say this section right here this green section here let's say this is the cervical segments this is the cervical segments okay and this is going to be consisting of how many spinal nerves eight pairs of spinal nerves so we're going to have eight pairs of spinal nerves this is important now how are these spinal nerves actually coming out let's pretend for a second you know how we're looking at it's an anterior view right let's say right here let's say that you have a specific bone right here this is say that's a part of your occipital bone so let's say this is a part of your occipital bone right and what happens is let's say right here I'm going to have another bone here let's say I have my cervical vertebrae here's the cervical vertebrae and let's say here's a cervical vertebrae right so let's say that this is Atlas and let's say right over here is actually going to be the occipital condyles now coming in between the occipital condyles and the atlas is going to be this spinal nerve and this would be C 1 so this would actually be C 1 and it's going to continue so if you go atlas and then you have another bone here let's say that you have the next cervical vertebra and the next cervical vertebrae here would actually be axis C 2 coming between Atlas and axis is going to be what C 2 so coming in between these guys are actually going to have C 2 and coming over here you're actually going to have C 2 and if we were to keep going you get the point there's going to be again how many spinal nerves though eight pairs of science phyla nerves so C 1 all the way to C 8 and some people get thrown off by this C 8 all that C 8 is it's just the actual cervical spinal nerve that's going in between the seventh cervical vertebra and the actual t1 okay now let's go into the next segment the next segment is actually going to be the thoracic segment this is the thoracic segment now the thoracic segment is actually going to be 12 pairs of spinal nerves so there's going to be 12 pairs of spinal nerves and this is going to be going from T 1 all the way to T 12 right and then if we keep going down let's go down another one we come down to the lumbar segments so then we come to the lumbar segments and the lumbar segment is actually going to be from l1 to l5 okay so if it's going from l1 to l5 then how many spinal nerves is that going to be that will be five pairs of spinal nerves so in this one you're actually going to have five pairs of spinal nerves okay then if we keep going down let's say we go down to the next one and we go to the sacral region the spinal cord sig original spinal cord so sacral segments so if we go to the sacral segments this is actually going to be consisting of again five pairs of spinal nerves five pairs of spinal learners and this is going to be again from s 1 to s 5 and the last one is actually going to be the coccygeal segment or coccygeal segment right and this is going to be primarily consisting of coccygeal one nerve and we'll talk about that when we talk about the actual sacral plexus so how many actual pairs of spinal nerves is that give us well eight plus twelve is twenty and then 20 plus 10 is going to be 30 and then plus this actual one right here 31 pairs of spinal nerves so how many spinal nerves is there total there's 31 pairs of spinal nerves okay now what we're going to do throughout the series of videos is we're going to break into each one of these segments so we're going to start off now in this video talking about the cervical segments particularly that of what's called the cervical plexus and then we'll actually you'll see that the cervical plexus out of these actual eight pairs of spinal nerves it's primarily only going to be coming from c1 to c4 with a little bit of the c5 nerve root for the phrenic nerve but we'll talk about that okay so now that we should understand this we should understand how the spinal nerves are coming out they're coming out through be technically through the intervertebral foramen in between the actual vertebrae and this will actually be coming in between the occipital condyles and the atlas for the c1 nerve all right okay so let's go ahead start with the cervical plexus so we said the cervical plexus should be consisting of these four right here but we're going to include c5 for the root and you'll see why so let's say we put here c1 and we're going to do this in like a nice little schematic diagram here so c1 we're going to have your c2 c3 c4 and c5 now what's going to happen is c1 when it comes out right it comes out between the Allison and the occipital condyles right when it's coming out it's going to give off two branches so let's say here it is and it gives off two branches one branch moved this way and it's going to form it's called the superior root of the answer servic Allis and then you know what else is really cool you know there's another cranial nerve that's actually running right in this vicinity hypoglossal nerve you know the hypoglossal nerve attacks are coming through the hypoglossal canal within the occipital condyles this is cranial nerve 12 the hypoglossal nerve will come out of the hypoglossal nucleus right and when it comes out it will move with this first cervical plexus right here right this first c1 now what's really cool is c1 will actually give off a branch that will move with the hypoglossal nerve so as the hypoglossal nerve is moving in this vicinity it picks up a branch from c1 now when that happens they run together so imagine this imagine me kind of circling this whole thing here and they're running a like an actual entire sheet here alright they're running in like this sheath what happens is this c1 will come out and it will supply two muscles right one of the muscles is going to be called the genial hyoid the other one is going to be called the gyro hi I'd so it supplies to muscles now the genie Ohio it is actually one of the super-high of muscles so it's actually going to elevate the high bone and the thyrohyoid muscle is actually going to depress the hyoid bone and elevate the larynx now out of this hypoglossal nerve since it's already here we might as well just show that the hypoglossal nerve will actually continue and it'll go to supply a couple other muscles will have an individual video on the hypoglossal nerve but i want you guys to know that will actually come out here and it will supply a bunch of different muscles of the tongue so it's going to supply the stylo glosses and the style of glosses is actually going to be one of the muscles it's an extrinsic muscle of the tongue and what helps to do is it helps to be able to elevate the tongue so it helps to elevate the tongue and not only elevate the tongue but actually retract the tongue another branch is going to be the high o glosses and the high o gloss this is actually going to be one of the other extrinsic muscles of the tongue which depress the tongue and retrack the tunnel another one is going to be the genial glosses and the genial glosses is actually going to be important for being able to protrude the tongue so being able to protrude the tongue and the last one is this going to give branches to the intrinsic muscles of the tongue and these are going to be the ones that basically change the shape of the tongue so whenever you have the ability to be like you're going to curl your tongue that's the intrinsic muscles of the tongue so again we have the hypoglossal nerve which is going to run with the c1 it's going to supply the style of glosses high/low glosses jena glosses and intrinsic muscles of tongue c1 will give off a branch that runs with the hypoglossal nerve to supply the genii Ohio which elevates the high bone and the thyrohyoid which is going to depress the high bone and elevate the larynx now what else do we have here then we said c1 is going to give off a superior root of the answer serba callus another thing is going to happen here look at this c2 is going to move forward and what's going to happen is c1 and c2 are going to give off these branches together they're going to communicate with one another and they have this communicating branch and the reason why they have is communicating branches coming out the back of the c1 and c2 connection there's going to be a branch that moves with another nerve another cranial nerve you know there's another one really really important one let's put this one in red this is the vagus nerve or cranial nerve 10 so cranial nerve 10 is actually going to be moving and as it's traversing this way it's going to pick up some of the branches from what from this actual c1 and c2 connection and they'll move together so let's actually show that as they're moving together so look at this oh yeah baby that's awesome okay so these guys are moving together here so there's a communication with the vagus nerve alright what else is going to happen another muscular branch that's going to be coming off of here is actually going to be going to some muscles which are responsible for flexing the neck and will allow for lateral flexion of the neck one of these is going to be the rectus capitis anterior you know the rectus capitis anterior is very deep muscle helps to be able to flex the neck right around the it helps to flex the neck and it's also going to be flexing the neck right around the actual c1 occipital condyle region so it's helping to flex the neck right around that joint process also it's getting off another branch the other branch is going to be the rectus capitis lateralis and you can already tell what this one does it's also going to be a very deep muscle it allows for lateral flexion of the neck so it does lateral flexion of the neck and then you can have another branch and this branch is actually called d longus capitis and this one also flexes the neck right around the actual atlas occipital region alright then c2 we said that it was actually have another branch right look what's going to happen here we're follow it in a second it's also going to give off an inferior route and we'll see that in a second then c3 is going to move here it's going to Traverse forward right here as it traverses forward it's going to give off a branch and this branch is going to interact with me see to watch this if the c2 is going to give off a branch and then these two are going to interact here and they're going to give off a couple branches here okay so it's going to be an interaction between C 3 and C 2 one of the branches is actually going to traverse this way and this branch is specific it's actually for the greater auricular nerve and the greater auricular nerve which is actually consisting of the c2 and c3 branches it's going to supply the skin over the ear and the skin lying over the parotid gland there's going to be another nerve that's coming out the back of this so there's another nerve that comes out the back of this this is called the transverse cervical nerve and the transverse cervical nerve is actually going to be important because it supplies the skin on the anterior aspect of the neck and the lateral aspect of the neck okay so again greater regular skin over the ear and the parotid transverse cervical is the skin over the anterior and lateral aspect of the neck now there's another one sometimes they're certain controversy and I'm going to make it a special especial color so that we there's no confusion but some literature will say that the c2 and c3 can make the lesser occipital well for right now most research is supporting that it's only going to be coming from the c2 branch so we're just going to have that here but again realize that there is certain literature that it will say Les Arcs dip Atal does carry some c3 fibers so lesser occipital and the lesser occipital nerve is important because it's going to supply the skin on the actual occiput so it's going to supply the skin on the occiput as well as the posterior aspect the neck and the actual lateral aspect to the back of the neck so again it's going to supply the actual occiput region it's going to supply the posterior aspect to the neck and it's going to plot lateral posterior aspect of the neck and even live the scalp alright then c3 is also really cool look what happens here it gives off another root and these two combined look at this these guys come together and what happens is the c2 and c3 come together when they come together they form what's called the inferior root of the ends of servic Alice why is this important because the answer serve accounts are going to supply a lot of different muscles off of this there's going to be four muscles that will come off and it's going to look like a nice little loop so look at this here's the superior route and the superior to the answer servic alice is coming from c1 the inferior root of the answer servic alice is coming from c2 and c3 so it's right to here so this is d this one here is the inferior root and this one right here is going to be superior root they come together and they give off four branches and these have to be in a special order from superior to inferior okay they have to be because there's some type of lesion there could actually be affecting of some of these actual muscles and not of the other ones all right so what are these ones so the first one the first branch is going to be the ELMO hyoid specifically the superior belly you know this omohyoid is actually one of the muscles that it's actually an infra hide muscle and also to be able to depress the hyoid bone there's another one which is going to be the sterno thyroid so the sterno thyroid don't get this confused with the next one because the stir the fire it actually depresses the thyroid cartilage the next one which is just inferior to it is actually called the sterno hyoid and this one depresses the hyoid bone and then there's one more branch here and this branch is going to be going to the inferior belly of the omohyoid so it's the omohyoid specifically inferior belly because you know together connected through an intermediate tendon right inferior belly if you guys aren't sure of some of the functions of these muscles watch our muscular anatomy videos okay because we actually go over all of these alright so now we've covered what is this big loop here called which is made up of the SU period of c1 and inferior to c1 c2 and c3 this is called the Ansah servic Alice okay now another thing coming off the back of c2 let's do this one in this actual maroon color here coming off the back of c2 it's going to give a branch here to these actual other muscles of the Flex to the neck and they're going to go from c1 all the way down to c5 so I'll actually draw a couple of afterwards but these are going to supply the longest coli and it's going to supply the longest capitis and we already know what the longest capitis does it flexes the neck what do you think the longest coli does it's also a very important muscle deep muscle it also flexes the neck and again they'd be coming off c2 and they'd be coming off c3 so again who is these longus I'm actually going to denote these with just an L to say longus so should be longus capitis and longus coli and this will be coming from c2 and from c3 so I'm going to erase this here again and just denote it with an L so we have a lot of room here so longus coli and longus capitis okay now another thing is going to happen here c3 is going to give off another branch here that's going to go to your scalings particularly the anterior and middle scalene okay so the c3 root let's do this one and this duty brown color actually let's do pink we are used to drown let's give off the c3 branch a c3 branch is actually going to run near with this and it's going to supply the scalenes and it's also going to supply the leavitt or scapula leavitt or scapula so if you know the scalenes are also very important for inspiration process primarily forceful so it helps you be able to flex the neck and the Leben or scapular also involved in elevation of the scapula then c3 is going to give off another branch right off its root it's going to give up so very if you'll remember any of these you have to remember this one this is of the most important one okay so let's draw here let's have a c4 right here let's have a c5 right here what happens is coming off of this c3 you're going to have a c3 here it's going to pick up branches from c4 okay so you're going to pick up branches from c4 and then it's going to pick up another branch which is going to be coming from c5 so this is why that c5 is actually important not technically on cervical plexus is only c1 to c4 but again c5 root is also important because it gives this branch here now if you look here we have this c3 c4 and c5 roots coming together to supply what what will all of us give way to all of this will give way to the most important nerve of all of these this is the phrenic nerve so this is going to the phrenic nerve the phrenic nerve is one of the most important ones and the reason why is because it supplies the main muscle of inhalation that is the diaphragm so supplies the diaphragm any type of damage to the c3 c4 and c5 nerve roots could cause extreme damage it can cause if this isn't able to work you could actually have respiratory arrest or respiratory failure because you're not going to be able to have inhalation activities occurring okay now another thing happens here so we got the this guy here now off of c4 we also said what you're also going to have a branch going to D longest coli and you're going to have a branch going to the longus capitis guess what else you're gonna have a branch to another branch of the scalenes and the leavitt or scapula you have another branch here which is going to the scalenes and a branch going to the lab at or scapula I'm gonna put L there for lavatory and again reduce flex the neck and this helps to elevate the scapula then another important one here coming from specifically c3 and c4 so now we're going to combine c3 and c4 this is another really important one c3 and c4 will actually come together in form what's called the Supra clavicular nerve so this is called E Supra clavicular nerve and this is a cutaneous branch meaning that it's actually going to be a superficial branch or supplies particularly the skin over the clavicle and the medial part of the deltoid right around the actual acromion region alright now there's another branch and then we have to talk about one more important thing here very very important after this one but again we already said that coming from c1 all the way down to c5 we would have longest capitis and longest coleye branches so let's show that again we're gonna have another branch coming here and this is going to be for the longest capitis ande longus coli okay now what I'm going to do is I'm going to make another little mini diagram because we have to talk about one more relationship and that is the relationship with the accessory nerve okay so let's come over here and let's talk about this accessory nerve okay now if you guys will actually go into this in more detail when we get to the cranial nerves but specifically if I were to have for a second let's say that I actually draw the actual little view of the spinal cord here again so let's say here is the spinal cord here right and let's say I get up to this point here you know when you get up to this point here where the actual medulla is you know here's the medulla let's say here I actually draw them a doula here so there's a cross section on the medulla right there's a hole in the skull here and this actual hole is going to be called the jugular for Raymond it's obviously out of proportion here but I'm just doing it so that we can understand what's actually happening here so this whole is called the jugular foramen now there's another hole where the actual spinal cord is moving through and this is called the foramen magnum what happens is from c1 so let's say here c1 here's c2 here's c3 c4 and c5 what happens is is c5 gives off a branch that traverses upwards c4 gives off a branch that traverses upwards c3 gives off a branch that traverses upwards c2 and c1 give off branches that traverse upwards now why is this important out of this you're actually going to have a branch that comes out the back and a branch that comes in the front so what would this one be this would be the posterior or dorsal ramus and this would be the eventual ramus and again this would be the ventral ramus and this would be D dorsal ramus and again if you had to continue here this would be the dorsal ventral dorsal ventral why is this important this little cord that you see coming up here from c5 all the way up to c1 that cord right there that I'm going to kind of circle that's running in between the anterior ramus and the actual dorsal ramus and it's actually just behind what's called the denticulate ligaments which are Pia mater extensions this is called the lateral funiculus and what happens is this actually moves upwards and again what is it moving from this is c1 c2 c3 c4 and c5 I'm only doing one side but this would be happening on the same other side right as it moves upwards you're going to have let's say here is the specific nucleus here and this is for the accessory nerve so this is for the accessory nerve most of the actual fibers come from what's called the nucleus ambiguus now out of this you're going to have this hypo gloss are e the accessory of the cranial part of it the cranial part of it will move through the jugular foramen right now what's important about this is this aspect right here there's another nerve that runs with it and this is called the vagus let's put this in blue so this is actually cranial nerve 10 what happens is most of the fibers from the the cranial part of the accessory nerve that's this black nerve most of the fibers go with the vagus nerve to supply a lot of the actual Ferengi laryngeal muscles right but this structure here you see this lateral funiculus as it comes up through the foramen magnum it'll actually run up through the foramen magnum and then down through the jugular foramen when it runs out it forms the main spinal accessory nerve so again the actual accessory nerve has this lateral funiculus such as running up through the foramen magnum and what happens is some of the fibers very few of them but some of the fibers from the cranial part of the accessory nerve is going to run up with the spinal part of the accessory nerve and when these run together they'll actually pick up a couple of more fibers they'll pick up some of the fibers from the ventral ramus of c2 to pick up some more fibers from the venture ramus of c3 and they'll pick up a couple more fibers from the actual Venture ramus of c4 when all of these move forward they go to two different destinations one destination is going to supply the trapezius so one destination is going to go to the trapezius muscle and the other destination is actually going to go to the sterno kLYDE oh I'm going to finish the name over here mastoid the sternocleidomastoid helps to be able to flex the neck the trapezius has many functions helps to elevate the staff it helps to retract the scapula it can do a lot of different things right now why is this important because as you can see the cervical plexus can give via the lateral funiculus it can give c1 all the way to C five connections to form thee what is this red thing right here running up through the foramen magnum this is called the spinal accessory nerve the spinal accessory nerve will run upwards and gain some of the fibers from the cranial part of the accessory nerve from the nucleus ambiguus and run through the jugular foramen most of those fibers though from the actual accessory nerve the cranial part will go with cranial nerve 10 the vagus nerve which is to go and supply the Ferengi lessels laryngeal muscles a lot of different structures but very small amounts of those fibers from the cranial part will move with the spinal part of the accessory nerve as it moves out then what happens again some of these fibers can actually go to the sternocleidomastoid and some of these fibers will go to the trapezius and then what else was really important we also said that it was important that dc2 ventral ramus gave more fibers c3 venture Ramos gave more fibers and c4 venture Ramos gave more fibers why is that important because the sternocleidomastoid only gets those from c-2 and c-3 and the trapezius is only getting defied the ventral remo fibers from c3 and c4 another really important thing about this i'll talk about it more but when this actual accessory nerve triggers continues forward and it gives off a branch of the sternocleidomastoid it moves past this anatomical region which is called the posterior triangle of the neck and when it moves to that posterior triangle the neck that's when it gives off its branch of the trapezius that's important because it can have some clinical correlations we'll talk about that with the accessory nerve okay so now that we had to understand all the connections that is moving with the accessory nerve okay so we've pretty much done everything here for the cervical plexus I envisioned so we talked a lot about the cervical plexus and again we went through almost every single type of root that you could have gone through obviously there is some other smaller branches but they're not as much clinically significant as as we wouldn't really need to talk about them okay all right now as we covered a lot about the sort of complexions I really hope all of it made sense I really hope that you guys enjoyed it if you guys did please hit the like button subscribe put some comments down in the comment section all right ninja nerds as always until next time