00:00
The vertebral column is
made up of multiple bones
rather than a single one,
which is great,
it gives us a lot of
movement and flexibility.
00:08
That means we have to have a
lot of joints all along the way as well.
00:12
And we already said that
these intervertebral discs
essentially act as
joints because they do
connect adjacent
vertebral bodies.
00:19
So we can consider that
our intervertebral joint.
00:23
It's not the typical
joint you might think of
in the sense that
it's not very movable.
00:28
It's a fibrocartilaginous
joint or symphysis,
which is really meant more
for support than movement.
00:37
If we look more posteriorly,
we again see those flat surfaces
we see a superior
articular facet,
and an inferior articular facet
what we see is
these two flat surfaces
or facets will meet
up with each other.
00:54
The superior articular
facet will line up perfectly
with the inferior articular facet
of the vertebra just above it.
01:03
And that will allow some
sort of gliding motion
and have a little
bit more movement
that we have at the
intervertebral joint.
01:11
So the movements we can have
are flexion when we bend forward,
an extension when
we bend backward.
01:22
But because we have
these facets as sort of plates,
and they can only glide they kind
of limit the degree of movement,
which is good because
we don't want to forget
that we have the
spinal cord in here
and we don't want
to bend too far
because we'll start to damage
the spinal cord inside
the vertebral foramen.
01:42
So those joints are also called
facet joints or
zygapophyseal joints
if you really want
to sound fancy.
01:50
And they're more of what
we would call a typical joint
or a synovial joint that
has a lot more movement.
01:58
A typical synovial
joint has a capsule.
02:02
It has a cavity.
02:04
And that cavity
is filled with fluid,
joint fluid or synovial fluid.
02:10
Because this is a synovial joint,
with repeated motion,
it can develop arthritis
just like any other joint.
02:16
And that arthritis can lead to a
lot of inflammation unfortunately,
as things become inflamed,
they swell.
02:23
And as things swell,
they compress on what's nearby.
02:26
And again, we have to keep in
mind we have spinal nerves nearby.
02:29
So that can cause
compression of spinal nerves.
02:32
So what you might need to do
is go into the joint space directly
to provide an intra-articular
injection to decrease the inflammation.
02:45
And that's something
that's typical
of pretty much
any synovial joint,
this just happens to be the
first example we've come across.
02:54
So again,
we have a lot of joints,
which is great because
joints mean we can move
and we have a lot of movements
we can carry out at the back.
03:03
For example, moving our torso
forward would be considered flexion.
03:08
Moving it backwards,
will be considered extension.
03:13
And if we go around to
a coronal point of view,
we also have side
to side movements,
we would call lateral
flexion and extension.
03:23
If we look from a
superior point of view,
we can see that we can
rotate to either side as well,
we can rotate to the left,
and we can rotate to the right.
03:33
And we can do a combination
of all of these at the same time.
03:39
So the fact that we
have multiple backbones,
rather than a singular
backbone is what allows
for this wide range and
combination of movements.