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  University of Idaho
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  Psychology Dept.
  University of Idaho
  Design - P&D  CTI

The vertebral column, first of all, consists of 26 bones.  It depends on how your organize it, and which anatomical author that you’re viewing of how they group those bones.  But, in essence, there are 24 individual vertebra and 2 groups that fuse together.  There is also a hole running through the middle of the vertebral column which is called the vertebral foramen.  They also have other holes as well, for example the transverse foramen. 

In addition to that, we also have what we call intervertebral discs which are located between each vertebra.  These help to form strong joints, provide some kind of flexibility for the vertebral column, and help to cushion shock within them.

The vertebrae are basically grouped into five different regions.  So, let’s talk about each of these in a little bit more detail.  The cervical region (as we see in slide four) contains seven bones.  They’re named C1 through C7.  C1 is also called the Atlas and C2 is called the Axis.  These are the vertebrae that only have three holes.  So, as you’re looking in DeArmond et al. and looking at the foramen that’s going through these vertebrae, you see the vertebral foramen (which in the middle of the vertebral column) and the transverse foramen (which are on each side and smaller.  These vertebrae in the cervical area also have smaller bodies, and have short processes that stick straight out the back.  You can actually feel these as you rub up and down the back of your neck.  C7 is a very prominent process that can felt at the base of the neck as well.  The Atlas and Axis are also extremely important.  As we can see in slide five, the atlas connects the occipital condyles of the skull with the axis.  This allows your head to move in an up and down direction.  The axis connects with the atlas.  Basically it allows your head to move from side to side.  Both of these are extremely important, and are especially important if you damage your skull as well. 

Let’s move on and talk about the next set of bones.  These are the thoracic bones.  We have 12 thoracic bones plus the discs between them.  The thoracic bones of the vertebral column are also connected to the ribs.  T1 is where the vertebrae of the top ribs basically attach.  They have a single vertebral foramen in the middle of each bone, and the body of the vertebra is basically a heart shape.  The processes in the back are also long and point down.  You can also over time develop an exaggerated thoracic curvature.  This curvature is what you see in a hump-back appearance. 

The next major set of bones (as we see in slide seven), consist of the lumbar region.  These consist of five vertebra and the discs of the lower back.  Here the vertebrae are much larger.  They have a bean shape, and the processes are short and point straight back.  The lumbar area is also the location for where we perform a lumbar puncture, or what we call the spinal tap.  Basically, it is done between either L3 and L4, or L4 and L5.  In addition, some people who have disorders in these structures develop an exaggerated curvature, which is called sway back or Lordosis.

The next group, as we see in slide eight, is what we call the sacrum.  The sacrum consists of basically five vertebrae that fuse together.  This fusing occurs in your late teens or in your early twenties.  So, we have one group of about five bones.  This is the location for epidural anesthesia.  Basically, the medicine is injected into the sacrum.

The last major set of bones in the vertebral column is like the sacral area and called the coccyx.  The coccyx is your tailbone.  It consists of one group which has four coccygeal vertebrae that fuse together.  These are very small bones and they’re located at the very tip of the vertebrae.  You can feel these bones on yourself and basically is your tailbone that’s out there.

Now in addition to the vertebra that we have, let’s talk a little bit about the intervertebral discs that we have.  Again, these are located between each pair of vertebra and they’re made up of what is called fibrocartilage.   Basically it adds support and absorbs shock.  We also have the intervertebral foramen.  Again, it’s the opening that’s found between two vertebrae.  This structure is extremely important because it is where the nerves go out to particular body parts.  It is not the same as the vertebral foramen.  So, we have the intravertebral foramen, intra meaning between, versus the vertebral foramen which is the hole that’s going down between the spinal vertebrae that we have in our system. 

Now, there are a lot of different disorders that we have with the vertebral column.  I’ve listed a few of these starting on slide 11.  The first of these is what is called a herniated or a slipped disc.  Basically, this is the protrusion or rupture of an intervertebral disc.  This is common as we get older.

A second disorder is what we call scoliosis, which is an exaggerated lateral bending of the spinal column.  The bend is not a front to back system; it’s more a side to side.  That can cause major problems later on in life. 

The third major disorder and which I’ve listed here is what is called spinabifida.  This is where you have an incomplete closure of the vertebral column.  I’ve listed several of these types of spinabifida on the following page (slide 12).  Usually, what you see here is based on the amount of damage or the amount of opening that’s within the vertebral column.  So let’s talk a little bit about each of these here for a brief second. 

The first one is Occulta.  This is relatively symptom less.  What we have is a small defect or gap.  The spinal nerves are usually normal, and most people who have this kind of disorder usually have no problems.

The next major type of spinabifida is Meningocele.  This is the rarest form.  What we have is a cyst surrounding the spinal cord begins to poke through a part of the spine.  Usually this can be removed by surgery and the person develops normally. 

The last one is called Myelomeningocele.  This is the most severe form.  Here the cyst contains the nerve roots of the spinal cord and often goes into the spinal cord itself.  As a result you may have spinal fluid leakage.  Ultimately, what we have here are very high risks for infections until the back is closed surgically.  Often we use antibiotics to give you some kind of temporary protection.  Usually you have leg paralysis and bladder and bowel control problems until the problem is resolved.

Now, spinabifida (as we see in slide 13) is most common in the lumbar sacral region.  It also occurs commonly with another disorder called hydrocephalus where you have too much water cerebral spinal fluid in the brain.  It’s correlated with a lack of B vitamins, specifically folic acid.  The treatment usually is surgical and done very, very early after birth (Usually one to two weeks post-delivery).  However, there have also been some new procedures that are being examined parentally.  You’re actually doing the surgery when the child is in the womb of the mother.

So, the vertebral column is extremely important for us, it does lots and lots of different things, it provides structure, support, and is also is going to be the structure that’s going to provide protection for a structure that we call the spinal cord.

In the next sections, we continue on with our discussion of the spinal cord.  So until then have a great day.