Structure of the Vertebrae (Nursing)

00:02 So that's the vertebral column as a whole.

00:04 Let's look at the individual vertebra that makes up the vertebral column.

00:10 So here's a superior view looking down on a typical vertebra.

00:16 You can see anteriorly it's one big flat disc, that's called the vertebral body.

00:22 But posteriorly, it's a lot more complicated.

00:25 And that part we call the vertebral arch.

00:29 So what are some of the parts of this arch? Well, the part that's connecting to the vertebral body is called the pedicle.

00:38 And then there are these projections pointing out laterally, called transverse processes.

00:46 And then that has another piece of bone called a lamina.

00:51 That connects it to this pointy process most posteriorly called the spinous process.

00:57 And that kind of makes sense if you think about animals that have spines, and we talked about the spine as being the most posterior aspect of the back.

01:05 That's why this is called the spinous process.

01:08 And you can see there's a hole or foramen that exists between the vertebral body and vertebral arch are vertebral foramen or vertebral hole.

01:19 And that's where our spinal cord is going to be housed and protected.

01:24 So here we have a vertebra from a bit of a tilted or oblique view from a superior lateral angle on the right side.

01:34 And from the side, we can actually see there's a bit of a notch superiorly called the superior vertebral notch between the body and the arch.

01:42 And just posterior to that is this flat plate called the superior articular process.

01:50 Similarly, there's a bit of a notch inferiorly called the inferior vertebral notch, separating it from this play called the inferior articular process.

02:00 And articular means related to a joint like to articulate is a joint movement.

02:06 And we're going to see that this is where we have one of the joints of our vertebral column.

02:12 Now there are some minor changes that exist along the length of the vertebral column.

02:17 For example, cervical vertebra, are going to have some extra holes or foramen out in the transverse processes called the transverse foramen.

02:28 And they're going to have smaller bodies.

02:31 And that process is going to allow for an artery called the vertebral artery to travel through it.

02:38 Similarly, in the thorax, we have some unique features.

02:41 We have more flat plates called costal facets and costal means ribs.

02:47 And that's because the ribs attach to the thoracic vertebra.

02:53 And the lumbar vertebra, well, they're a bit larger, they're carrying a little bit more weight, and they're sort of shorter and stouter spinous processes.

03:01 But basically, you can think of a typical vertebra as being a lumbar vertebra.

03:06 And then these other features are unique to the cervical and thoracic vertebra.

03:12 Now, there are some atypical vertebra that really look different from the rest though.

03:17 And the first is the first cervical vertebra or C1 also called Atlas.

03:24 And that's because of that Greek guy who was carrying the earth on his shoulders, that's basically what C1 is doing.

03:32 This is the superior most vertebra holding the skull.

03:36 That's how it gets the name, Atlas.

03:39 And it looks very different.

03:39 We don't really see much that look like a body and arch, we kind of have one bumper tubercle anteriorly, and another posteriorly, so we have an anterior tubercle and a posterior tubercle.

03:51 But not a lot of typical stuff here.

03:54 We also see that there are these flat processes called the superior articular facets.

03:59 And they're oriented a bit differently because they're going to be where the cranium rests.

04:07 Just below it is another kind of oddball C2 also called Axis, like axis like a wheel spinning on its axis and we'll see why it's called axis.

04:17 So it also has some superior articular facets that are going to interact with the C1 vertebra above it.

04:25 But its unique feature is this pointy thing called the dens or odontoid process.

04:31 Dens meaning tooth, it looks like a tooth of bones sticking upward.

04:36 And when you put the two together, it makes a little bit more sense.

04:40 This is forming something called the Atlanto-axial joint using the other words for C1 and C2.

04:50 And you can see how we get the name axis because C1 is basically rotating around this dens and it's providing the rotation you would use for example in shaking your head 'No'.

05:02 Now, on the C1 vertebra, as we mentioned, we have these facets where the cranium is gonna rest.

05:09 And the portion of the cranium, is something called the occipital condyles.

05:13 Condyles is kind of a word for bumps.

05:15 So there are these bumps on the occipital bone of the skull that rests directly on this surface.

05:23 And again, we can rotate around the dens in part also because we have this ligament called the Alar ligament surrounding it.

05:30 So we basically can use this as a focal point for rotation.

05:36 So here we can see with the skull added how all three of these structures come together.

05:43 There's our cranium resting on C1.

05:47 And the way that that superior articular facet is oriented, it helps us carry out motions like flexion extension, like nodding your head, 'Yes'.

06:00 So we have 'No' at C1, C2, and then we have 'Yes' between C1 and the skull.

06:08 The other odd balls of the vertebra are the ones down at the very inferior and the sacrum and the coccyx.

06:17 And that's because here's where a lot of vertebra have just fused into a single bone.

06:23 So here we have the sacrum.

06:25 Again, it's fused vertebra, typically five that have basically formed a single bone.

06:31 It's still has superior articular facets for the last lumbar vertebra, which would be the fifth or L5 vertebra.

06:39 But then it really looks like one continuous bone.

06:43 And if we look through it, we actually see there are still openings called sacral foramina.

06:48 Again frame and just means hole.

06:50 For the spinal nerves in this area to still exit even though they fused into a single bone.

06:57 And they'll enter at the superior portion through an opening called the sacral canal.

07:01 And when we talk about the nervous system, we'll see that the spinal cord is basically stopped being a chord and just individual spinal nerves at this point that will enter that hiatus and exit out the sacral foramina.

07:14 And then finally, at the very end, we have 3, 4 or 5 fused vertebra called the coccyx, and it's at the very tail end which is why it's also sometimes called the tailbone.

07:28 And the sacrum is very important not just as a back structure, but because it's what's going to connect us to the pelvis and lower limbs.

07:37 And we come in a very important structure.

07:39 We talk about transmitting force and movements from our hips.