hello anatomy friends this is dr alsup and in this video we will be talking through
the basic composition and structures of the vertebrae specifically the movable vertebrae
and we're really going to discuss how to differentiate or distinguish between those
three types of movable vertebrae now i think you will actually find it surprisingly easy
and i'm not just saying that so let's get right into it alright for starters there are going
to be three main parts of a typical vertebrae so you'll have these in all three types of vertebrae
there is the larger and relatively massive body which is going to be anteriorly placed
it's between these bodies that there will be the intervertebral for uh intervertebral discs
and these will really give strength to the vertebral column and support the body weight
and the bodies will actually increase in size the more inferior you go the vertebral arch is
this whole area that is outlined here in light blue and as you can see it's a bit
more complex with lots of processes and facets and we will come back to this in the next slide
but i do want to before we move away from here uh talk about how all vertebrae will have this
vertebral foramen and it will be various sizes depending on what level you're at but they're
going to contain the spinal cord and the roots of the spinal nerves along with the meninges
and associated neurovasculature so an extremely important area right here so let's talk through
some of those interesting complexities of the vertebral arch and you'll have these cute little
feet down here called pedicles and these are going to project posteriorly because remember the body
is going to be anterior and they'll project from the the vertebral bodies and connect with these
two flat plates of bone called the lamina and these laminae will unite kind of along the midline
and from this vertebral arch you'll also have seven processes yes seven processes two are going
to be projecting posterior laterally and these will be the transverse processes and these are
kind of located right at where that pedicle meets the lamina so it kind of shoots off from there
there'll be one posteriorly projecting spinous process which is located close to the midline
and you can really palpate these if you palpate along the midline of your back you're feeling
those spinous processes and additionally there will be four articular processes
two superior which you can see here and a little bit here
and two inferior so you can only see the superior ones here and each will bear an
articular facet for articulation with a nape the neighboring vertebrae's articular facet
there will be these notches in the bone between the articular processes and the body right here
and here um and when you put those together so there'll be an inferior and a superior one
you put those together and you will have what's referred to um as intervertebral foramina so
you have a inferior one here and a superior one here to create an intervertebral foramina
and you will have dorsal root ganglia located in these foramina and you'll
understand what that is a bit more in some later videos but also importantly
this is going to allow the spinal nerves to exit the vertebral column so through
each one of these foramina you're going to have a spinal nerve that is exiting
all right let's turn our attentions to how we are going to differentiate between these movable
vertebrae starting with the most superior the cervical vertebrae of which there are seven by
far the easiest way to tell you are looking at a cervical vertebra is if you see these relatively
large transverse foramina not the vertebral for foramen but these transverse foramina on
either side of the body in this relatively small transverse process of the cervical vertebrae you
know you're looking at a cervical vertebra that's why i have it in all caps and an exclamation mark
you know i mean business here anytime you see that you know you're looking at a cervical vertebra
and it's through here that the vertebral artery ascends from the root of the neck to make its way
to the brain and the vertebral artery is one of the two dominant arterial sources for the brain
other things that are unique to the cervical vertebrae is that some of the its processes are
what's referred to as bifid meaning that it kind of is split into two separate projections you can
see that for the spinous process you can also see it here in terms of the transverse process
not all are bishop not all cervical vertebrae are bifid and there is considerable variation
between individuals here but you may see it in the cervical vertebrae
there are two cervical vertebrae that are unique so we often describe them separately c1 or the
atlas will articulate with both the occipital bone of the cranium and c2 and it is almost completely
ring-like it also lacks a body as well as um a spinous process so very large articular
surfaces ring-like but what do you still have there you still have a transverse foramen
so you know your cervical c2 or the axis is a very robust vertebra with a notable superior
projection referred to as the den sometimes you hear it referred to as the odontoid process
and this is what serves as a pivot about which the rotation of the head can occur
so if you're shaking your head no it's kind of going around this region between c1 and c2
next we have the 12 thoracic vertebrae and what is truly unique about the thoracic
vertebrae is that they articulate with the ribs and they do so on both the bodies and
the transverse processes so you'll have these facets and hemi facets
for these articulations so if you have those you know you're looking at a thoracic vertebra
additionally the spinous processes are not notably inferiorly projecting
last but not least are the lumbar vertebrae of which there are five and for me the best
way to tell i am looking at the lumbar vertebra is that these are big big big
that is kind of the most distinctive thing about the lumbar vertebrae
and also you can use the process of elimination there are no transverse foramina there are no
facets for rib articulation but it's really that size that gives it away
although admittedly some of the inferior most thoracic vertebrae can be on the larger side
all right that brings us to the end and our favorite the summary slide as you can see here
please take your time to review and always reach out with any questions
thanks for your time and attention