hello everybody and welcome back to another Anatomy tutorial today we're going to be looking at the anatomy of the cervical spine particularly looking at c-spine x-rays now there are three main views that we take when looking at the cervical spine we're going to start with our lateral view move on to our frontal view and then assess our open mouth view or our Peg or dontal view of the sea spine now before we get on to looking at the Anatomy on an X-ray I first actually want to look at the CT scan so we can gain a greater appreciation for what the 3D morphology of the cervical vertebra are they are quite different to the thoracic and Lumbar vertebra and it's difficult when we look at an x-ray and try and appreciate which bits of the vertebra are where because everything is superimposed on top of one another so let's head over to a CT scan and then go to our x-rays so here we have an axial bone windowed CT we can head up into the skull base first now this is an image you should be familiar with if you've watched the skull based parameter videos you should be comfortable naming these various parameter that are passing through and as we head down towards our occipital bone we should find occipital condyles that articulate with our Atlas our C1 so here is the anterior body of our C1 the anterior Arch and as we head down inferiorly a little bit more our posterior Arch here of C1 now C1 is called the atlas like the Greek god the atlas holding the globe up and that's exactly what it does it sits at the base of the skull and articulates with that occipital bone around the foramen magnum region there you can see how anterior Arch here find our lateral bodies we've got transverse foramina that allow for our vertebral arteries to go up into the base of the brain and we can see these transverse processes out the side to see one transverse process is actually quite large in comparison to some of the other cervical vertebra and then we have this posterior arch with a posterior body here and sometimes a very small or rudimentary spinous process you can see our anterior Arch is surrounding this structure here which is our dense or our odontoid process of C2 sitting below it you can see that our C1 or our Atlas doesn't actually have a vertebral body and this is kind of a remnant of that vertebral body here with C2 contributing this dense process allowing us for rotation and flexion and movement at that point here there's a ligament that comes across here a transverse ligament that holds this dense in place and we've got an articular surface here that allows for articulation between the anterior body of our C1 and our dense process so let's move down we're going to see the dense fan out into the body of C2 our axis sitting below our Atlas and we can see as we head further down C2 we get this posterior Arch and this is our spinal canal so we can see that C2 has a small vertebral body it's still got transverse foramina allowing for the vertebral arteries to flow up then it's got a lamina heading backwards to the spinous process also a very small spinous process on C2 now C1 and C2 are Atlas and our axis so I have quite different morphology to the rest of the vertebra so let's pick a random vertebra here we can see here that we have our vertebral body our transverse foramina allowing for those vertebral arteries to come up towards from the subclavian arteries all the way up to the Brain before they fuse to form the basilar artery away from our vertebral bodies we have what's known as the pedicle the pedicle then heads out and in our cervical spine our transverse processes here it's kind of a bifid transverse process it's actually kind of anterior to our particles and you'll see that changes as we head down into the thoracic vertebra our laminar posteriorly fuse to form our spinous process and one of the distinctive features of our cervical spine is that we have these bifid spinous processes especially in a superior region of the cervical spine we then have a mass of bone here that we call our pars into articularis that actually is the region between our inferior and Superior processes that allow for those facet joints to form we can see a Facet Joint here so our pedicles our Paws into articularis and our lamina heading out towards our spineless process with our vertebral body at the front and our transverse processes in our cervical spine quite anterior so let's head all the way down into the thoracic spine so we can see some of those differences here we know this is a thoracic spine because now we've got ribs articulating with these transverse processes you can see an anterior vertebral body and as we head further and further inferior in the spine that vertebral body gets bigger and bigger it needs to allow for more and more weight bearing as we head further down we've now got large well-defined pedicles that we didn't really see as well in our cervical spine and you can see our transverse processes are now posterior to that pedicle there and then we have our lamina smaller more angulated lamina heading out towards our spinous process which is much larger as we head further down in the spine and it's not bifferid here as you can see so let's now go to our X-rays and identify these various structures on the three different views so let's start by looking at our lateral X-ray and we can get probably the most information from our lateral so it's a good place to start the first thing I like to do when looking at the cervical spine on an X-ray is make sure we've got correct alignment mull alignment of the spine is a great indicator for something else happening that's wrong if we see metal alignment we need to find the pathology so before we can ascertain whether this cervical spine is indeed well aligned we first need to check that we have the correct angle on our lateral here that the X-ray itself is not rotated and the best way to do that when looking at a lateral cervical spine x-ray is to find the angle of the mandible here we can see on this posterior surface of the mandible the left and right mandibles line up well if we were rotated at all there'd be malalignment of those posterior surfaces so we know that this patient is square on to our X-ray and we can check for lateral tilt of the head or neck by looking at the inferior surface here we want to see that they're generally well aligns and here we can see the two inferior surfaces there's not much difference between those we've caught it on the right angle and actually on a true lateral there will be a slight difference due to the Fanning out of those x-rays as we head towards the scanner so now that we know the X-ray is well aligned let's see if the cervical spine itself is well aligned now the first line that we look at is called the anterior vertebral line now all of these lines that we look every once are slight low doses to these lines we don't want them to be dead straight or any kyphosis in the cervical spine so you can see here if we follow the anterior surfaces of those vertebral bodies we have a nice smooth little dotic line then we can head posteriorly and we want to do the same here look at the posterior line along those vertebral bodies we've got a nice smooth little dotic view here this line represents the posterior longitudinal ligament and the anterior line is the anterior longitudinal ligament the next line we look at is what's known as our spinal lamina line so we can see our spinous processes here they're a little bit less dense than our lamina that head out sharply from our Paws into articularis heading towards that spinous process making the posterior arch of that spinal canal so here is our spino lamina line there hitting across again it's smooth it's lordotic it's slightly more ordotic than our anterior and posterior lines and the last line we look at is our posterior spinous line we take the tips of these spinous processes and join them up and what we're looking for here is that there's a nice smooth line it's quite low dotic normally when joining these finest processes and we don't want any major step off between one vertebra and the other and here we don't really include our C1 spinous process if it does have a spinous process we start from C2 and draw that line so we've got our anterior vertebral line posterior vertebral line our spinal lamina line which also correlates to where our ligamentum flavum is and this is the posterior border of our spinal canal so our spinal canal lies here between our posterior vertebral line and our spinal lamina line and then we have our posterior spinal line so now that we know it's well aligned let's have a look at some of the anatomy of the cervical spine we'll start at C1 now Atlas you can see our anterior body here forming almost this oval shape with a flat posterior surface that articulates with the anterior surface of our dance if we follow the outline of the dance here it protrudes into that C1 vertebra the space between our anterior surface of the odontoid and our posterior articular surface of this anterior body of C1 should be less than three millimeters in adults and less than five millimeters in children so that Gap gets slightly smaller as we go through puberty we can then look at our posterior body of our C1 Atlas as well as the small spinous process here moving down to C2 we can see our vertebral body as well as our dance heading forward and then our laminar heading posterity towards our spinous process if you look at the shape of these vertical bodies of our C3 to C6 you can see the superior end plate of the vertebral body is quite flat and our inferior surface has this curved appearance with this protrusion anteriorly and this is normal morphology for our cervical spine and that gets flatter and flatter as we head out towards up thoracic spine the spaces between our vertebral bodies are where our intervertebral discs lie we can't see the discs on an X-ray but we can appreciate the space that they create you can see on the superior corner of these vertical bodies we have more dense regions than the rest of the vertical body and this is our pedicle heading out towards us as well as our transverse process coming out here now transverse process has that transverse foramina that allows the vertebral arteries to head up through the cervical spine protected by those bones because it's a very vulnerable region on the body and then heading up through alpha frame and Magnum eventually becoming our basilar artery here we can see the joint facets let me just go and draw these we can see the Facet Joint here between our two cervical vertebrae this is between C2 and C4 lc2 to C3 faceted joints a bit more difficult to see because of the angle of that Facet Joint it's a bit more facing medially than the rest we can look at these facet joints and in between the Facet Joint this part of bone here is called our pause into articularis from there heading out towards our spinous process that region there is called our lamina And Then There Our spinous process heading out so our pedicle giving rise to our transverse process then heading out towards our pause into articularis our lamina and our spinous process now there are a couple of other things apart from the cervical bones that we can look at here we've mentioned the mandible coming in here if we head to the very top of our image we're almost cutting it off here but here is our seller turcica now celestica then heads down a bone known as alkalivus and our clivers should then be pointing towards the tip of our dontoid process in front of that cellatosica or elsephenoid sinuses that you would recall from our spheroid sinus talk and then we have some soft tissue that is anterior to our cervical spine here and it's really important to note the thickness of these soft tissues we can see how nasal cavity here then heading to our oral cavity which ends at the level of our hyoid bone you can just see how hyoid bone there is our nasopharynx our oropharynx below that is our laryngopharynx and then you can see the laryngeal cartilages here our larynx and our trachea are heading off towards the mediastinum so from C1 to C4 let's count it out one two three four this region above here this soft tissue is known as our retropharyngeal soft tissue below that is called our retrotracheal soft tissue now one of the questions that you can get asked I can kind of catch you out is how many cervical vertebra there are and if you know this well it might seem silly to you but people get confused because we have eight cervical nerve Roots but only seven cervical vertebra that's important to know that we should be able to see the whole of this seventh cervical vertebra in order to adequately assess the cervical spine on a lateral X-ray and hopefully we'll see a bit of T1 coming in as well now why are there seven cervical vertebrae and eight cervical nerve Roots well the first nerve root comes in above C1 so the nerve roots are named according to the vertebrae that they come out above and then we'll have C7 coming out above C7 and then the space between C7 and T1 that nerve root is called C8 from the thoracic vertebra down our nerve roots that are associated with the corresponding vertebral body then come up below the vertebral body that's another difference of the cervical spine as opposed to the thoracic and Lumbar spines now it's quite difficult to appreciate on this view the pedicle coming out straight towards us because before shortening that pedicle we got superimposition of this transverse process and this pause into articularis it's quite difficult to appreciate and we know that the nerve Roots come out between those pedicles and if we want to see that space where the nerve root is coming out what we can do is get an oblique view as you can see like this we've taken a lateral View and tilted the patient slightly you can see now our vertebral body here and our pedicle coming off of that vertical body here are our facet joints we've moved those facet joints out laterally like that and allowed for those pedicles to now come into our plane and here we can see the pedicles make the superior and the inferior borders of this intervertebral foramen which is where our nerve Roots come out and it's important to note that our transverse processes are coming out anteriorly from these pedicles as we looked at on our CT Scan they lie quite anterior to those pedicles and above those we get what's known as an unsolute process a proportion of bone that heads superiorly from that vertebral body that can then impinge on this space we can see our internet process better on our frontal view so let's have a look at our frontal view and while we're on the topic of the Anthony process you can see here this process hitting up superiorly this there is our ansonet process and growth of those processes can impinge on those nerve roots coming out between the pedicles now before we can review any of the anatomy let's make sure we've got the correct alignment one of the easiest ways to know that you've got the correct alignment is to look at the trachea here and see your spinous processes posteriorly and you want your trachea and your spinous processes to be aligned spinous process are really Superior trachea is anterior any rotation we're going to get malalignment of those two we can also look at the track here and our proximal portions of our clavicles here and make sure the distance between those and the track here is generally quite straight our trachea can hit off a little bit more to the right so sometimes it's better to look at the spinous process itself between those clavicles so let's have a look at some of the anatomy on the frontal view on this view we can actually see our C2 body heading up towards our dontoid process or our dance and heading across like that there's our lateral bodies of our Atlas our C1 and then we'd be able to count the cervical vertebra down we can see the bodies of our cervical vertebra here these are the typical shape of those vertebral bodies Our pedicles will be heading out we can just see our transverse processes coming out like that and that's what it makes these small bumps along the side of our cervical spine frontal x-ray sometimes we have a cervical rib coming out here and it can be very easy to call this vertebra here T1 especially if we have that cervical rib the best way to know that this is in fact C7 is C7 has these large transverse processes that angle downwards angle inferiorly and t1's transverse processes actually angles superiorly like that so we get this angle here this diamond shape that is the joint between C7 and T1 there we can see our first rib coming off of T1 some other Anatomy to note is to look at our spinous processes you can see here as we head superiorly we have these buffered spinous processes like that and then they become unified we get single spinous processors as we head down towards the thoracic vertebra we can see our facet joins here we're not going to be looking through the joint itself because those joints are lying at an angle to our frontal view but we can appreciate those joints here and here and here and this region here this region of boring is our pause into articularis and what we get is an interarticular column being formed here as well as our vertebral column being formed there we can look at the trachea itself and as we head up towards the larynx that trachea Narrows and we get our piriform recesses here as well of our trachea so then we head up into the Oro pharynx here is our track here heading down this loosen so you can confuse you the bone is not loose and it's the trachea overlying the bone these vertical bodies are in fact normal let's move on to our last View and this is our Peg view or our open mouth view we first check that it's technically sound we can see our teeth line up with this occipital bone across there then we know we've got a good view into our C1 which is here which wraps around you can see these wrapping around the odontoid process we wanted to see that the space between our dance or our downside process is the same on both sides between these lateral bodies of our C1 and again we want to see that the lateral bodies of C1 match up to the lateral bodies here of C2 you can see our C2 spinous process here is also bifid along that side and here is our C2 virtual body that extends upwards into our dance and really this open mouth view is to establish the relationship between our C1 and C2 and make sure that there's no fractures between any of those bones so we've looked at our lateral view our frontal view as well as our open mouth View and the most important thing when assessing a cervical spine x-ray is checking that you've got good alignment of the bones and then specifically looking at each portion of those vertebrae because the anatomy is all overlying one another we need to systematically go through the regions look at the virtual body look at the pedicle then look at our transverse processes then look at our past interarticularis as well as our facet joints then look at our lamina heading back towards our spinous processes if we can go through the cervical spine x-ray systematically like that we're much less likely to miss anything and if you remember one thing is look at the surrounding soft tissue that can often be the clue that something sinister is happening within the bones of the cervical spine so thank you very much for watching today's video I'm really appreciating all the comments and the messages that I've been getting saying I must continue this series so that's what we're going to do I'll see you all in the next video goodbye everybody