By Elizabeth A. Murray, Mount St. Joseph University
The Anatomage computer software presents images from the Visible Human Project. Anatomage can help in diving deep into the vertebral column, the body’s main axis of support. We can see an anterior view with the entire rib cage on. If we look at a side view, we can see how the stacking of seven cervical vertebrae, 12 thoracic vertebrae, five lumbar vertebrae, and the sacrum and coccyx all contribute to this axis of the body.
If we address the spine, we need to remember there are seven cervical vertebrae of the neck region, 12 thoracic vertebrae that each have a rib attachment, five lumbar vertebrae in the low spine, and then the sacrum and coccyx, which form the tail end of the vertebral column.
If we want to see how the vertebrae stack, we could take a side view. And here we find the curvatures:
- the cervical curvature, which is a secondary curvature gained when a baby begins to hold their head up;
- a thoracic curvature, which reminds us of that primary curvature of the fetal position;
- the lumbar curvature in the low back and the sacral curvature.
It’s the stacking of the vertebral column that really gives us our flexibility in terms of twisting motions of the body.
If we want to take a look at an individual vertebra, we can highlight it, and here’s our third lumbar vertebra with its main bony features. We see the body of the vertebra, the pedicle, the transverse processes that stick out to either side, and the inferior and superior articular surfaces that are going to link the vertebrae together.
Posteriorly, we see the spinous process. And if we bring the spine back, we can see how the stacking of all of the vertebrae contributes to the great degree of flexibility that we have in the spine, and how one vertebra’s inferior articular facets overlap with the superior articular facets of another.
On the side, we get the sense of how small openings are left between adjacent vertebrae for the spinal nerves to come out. We can see the spinous processes. We can feel those in some areas of the spine and not in others because of the presence of ligaments.
This article comes directly from content in the video series How We Move: The Gross Anatomy of Motion. Watch it now, on Wondrium.
The Cervical Vertebrae
So, let’s take a look at the first couple of cervical vertebrae by taking away the skull. Now we can see C1, called the atlas, because Atlas held up the world like atlas holds up our head, and then we see it followed by C2, which is known as the axis.
We can see that C1 has a ring-like structure; it lacks the typical anatomy of a standard vertebra. And if we remove it, we can see the dens, or odontoid process, of C2 that allows for the great deal of rotation we see between the skull and C1 sitting on top of C2.
It needs to be remembered that there are 12 pair of ribs, and we designate them as true ribs if they have their own individual attachment to the sternum and then false ribs if they either don’t connect to the sternum at all or borrow the cartilaginous attachment of rib seven.
If we look at rib one, and continue till rib seven, we notice that they all have their own cartilaginous attachment to the sternum, which makes them true ribs. Ribs eight, nine, and 10 borrow the attachment of rib seven. So, they are a type of false rib. And ribs 11 and 12 are the floating ribs that have no attachment to the sternum at all.
The sternum itself is composed out of the manubrium, the body, and the xiphoid process. And, this manubrium meets the body at a ridge called the sternal angle, which is an important anatomical landmark.
Each rib articulates with two points on a vertebra. The rib tubercle attaches to the transverse process, while the rib head attaches to the body of a vertebra. So, that’s how the ribs articulate with the spinal column itself.
The Ligaments of the Spine
Coming to the ligaments of the spinal column, we need to remember that we have to keep this spine as intact as possible without any shifting, because the spinal cord itself is inside the vertebral foramina. So, to take a look at those ligaments, we need to take off the rib cage, and the upper limb bones, so we can really focus on this spine.
There is a super spinous ligament that runs down the length of the spinous processes, and it’s enlarged up near the neck as the nuchal ligament. That’s why we can’t feel the spinous processes on cervical vertebrae very well. And then if we tilt just a bit, we can see the interspinous ligaments, each one is its own entity, and we can see ligamentum flavum. Again, each one is its own individual ligament.
Now ligamentum flavum is on the inside of the vertebral canal, whereas other ligaments are on the surface. For example, we can see from the front here, the anterior longitudinal ligament that runs down the length of the vertebrae. And if we section the vertebral column in half, we can get the sense of how the intervertebral foramina allow the nerves to exit, and anterior to them is the posterior longitudinal ligament that is the counterpart of the anterior longitudinal ligament that runs down the anterior surface of the bodies of the vertebrae.
Common Questions about the Vertebral Column
The Anatomage company‘s use of computer software to present images from the Visible Human Project has been very helpful.
There are 12 pair of ribs, and we designate them as true ribs if they have their own individual attachment to the sternum and then false ribs if they either don’t connect to the sternum at all or borrow the cartilaginous attachment of rib seven.
The spine has seven cervical vertebrae of the neck region, 12 thoracic vertebrae that each have a rib attachment, five lumbar vertebrae in the low spine, and then the sacrum and coccyx, which form the tail end of the vertebral column.