hello anatomy colleagues and welcome to station number 16 and this is one of my
all-time favorites because i love to talk about the differences between the movable vertebrae and
how we're going to be able to identify them and as you recall when we're talking about movable
vertebrae there are three types they're going to be the cervical in this region the thoracic
and the lumbar down here so kind of the lower back region we'll have separate videos on the
immovable vertebrae the sacrum and the coccyx in later stations so let's
talk about how we're going to be able to identify a cervical vertebrae from the rest
and i find this one the easiest to be able to identify because of these giant foramina
right here now these are not the vertebral foramen all vertebrae are going to have that that is where
the spinal cord is going to be traversing but right here in these transverse processes which are
quite small when we're talking about the cervical vertebrae you're going to have these transverse
foramina and only the only cervical vertebrae have these and this allows for the vertebral artery
from the subclavia a branch of the subclavian artery to ascend up through the neck in order
to make its way to the brain and so it's going to be one of the major suppliers of the brain
so only these cervical vertebrae have this additionally both the transverse processes
and the spinous processes could be bifid and meaning that it kind of splits into
two projections and not all cervical vertebrae will have this and there's
some variability between individuals but this is something that you do
often see associated with the cervical vertebrae but you always have these transverse foramina
there are three special types of cervical vertebrae the first two vertebrae number one
and two are going to be the most distinct and c1 which is this one right here or otherwise known
as the atlas think of atlas holding the world on his shoulders or bearing the weight of the world
so the atlas or c1 is articulating with the head so it's articulating with the occipital condyles
of the occipital bone and as you can note here we have a fairly distinct ring of bone
with no distinct body or spinous process but you still have transverse foramina right
so this will be c1 c2 is a very robust vertebra and it will have a spinous process that will
have a body but it does have this very distinct projection it's a superiorly facing projection
referred to as the dens sometimes you hear it referred to as the odontoid process and this
dens will project into the c1 region in order to allow for that rotation to occur between c1 and c2
the other special vertebra is going to be c7 so if this is one two three four
five and six this makes this one c7 and what is unique about c7
is that it has a very long and inferiorly inferior posteriorly projecting spinous process that can be
palpated and sometimes it can be seen throughout the skin particularly if you flex the vertebrae
it typically is the longest projecting spinous process although oftentimes t1
is going to be very close which is looks to be the case in this particular donor here
so c7 is has this very distinct spinous process and this helps in terms of counting vertebrae as
well thoracic vertebrae are going to have what's referred to as costal facets and these will be
associated with the body this one right here is a hemifacet and the transverse process and these
are going to be smooth areas of bone which will allow for articulation with the costal cartilage
but specifically those ribs so you will only have these associated with the
thoracic vertebrae so that's something that's very distinct for the thoracic
and lastly there are the lumbar vertebrae and they are going to be by far the largest
so if you have quite a few vertebrae and you're able to compare the size if it's
the largest ones those are typically the lumbar but for me i always kind of just use
the rule of elimination so it doesn't have a transverse process or excuse me it doesn't
have a transverse foramen certainly as a transverse process because all vertebrae
are going to have that to some extent it doesn't have costal facets either and they are just rather
large so that would be something to kind of look at in terms of the lumbar vertebrae
its size is definitely going to be its most distinctive characteristic and you can see
the body is going to be quite large in comparison to the other ones but of course if you get into
some of the the more inferior thoracic vertebrae they are also increasing in size as well so you
have to kind of look for those costal facets on those particular ones all right excellent so
hopefully we have some clues as to how we're going to differentiate between the movable vertebrae if
you have any questions on these specifics please reach out and i will see you in the next video