What makes up the spine?
The vertebrae are the bones that make up the spine. These bone’s primary purpose is to provide a hard protective layer around the spinal cord. They also provide an attachment point for the arms, and legs to the center of the body. Lastly, the vertebrae allow us to stand up and walk against gravity. They are divided into 4 segments:
- Cervical vertebrae: These vertebrae make up your neck.
- Labeled C1-C7
- Thoracic vertebrae: These vertebrae make up the upper back, and provide an attachment point for each pair of ribs
- Labeled T1-T12
- Lumbar vertebrae: These vertebrae make up your lower back, just above your belt line.
- Labeled L1-L5
- Sacral vertebrae: These vertebrae make up the end of your spine, below your belt line.
- Labeled S1-S5
Discs lie between each vertebrae. The primary purpose of a disc is to allow for padding and shock absorption. For example: when you land from a jump, the top vertebrae comes down onto the disc like landing on a pillow, rather than landing on a rock (the bottom vertebrae). Each disc has two layers:
- nucleus pulposus: the nucleus pulposus is the center of the disc and has a jelly-like consistency. It is made of water and proteins called proteoglycan.
Annulus Fibrosis: The Annulus Fibrosis is the outer layers of the disc, and has a firm texture. This aspect of the disc is aligned in layers of rings around the nucleus pulposus.
3. Spinal Cord:
The spinal cord lies in the middle of each vertebrae. This is called the spinal canal. The spinal cord is the mid-point of information transfer from the brain to the body. So, the spinal cord acts like a train of moving information from the body to the brain, or the brain out to the body.
4. Spinal Nerve roots:
The spinal nerve roots branch off from the spinal cord. So these nerve roots are like train stops, where certain information must exit the train to get where it needs to go. These nerve roots carry two types of information: sensory or motor.
- Sensory Information is what comes from your skin and muscles through your spinal cord, and into your brain. which includes things like temperature changes, pressure changes, and even pain.
- Motor Information is what comes from your brain, into your spinal cord and out to your body, which includes things like how to move your fingers to type on the keyboard, or how far to reach so you put your cup of coffee back on the table (and not the floor). Each nerve root sends slightly different information to and from the brain.
The nerve roots are labeled like the vertebrae. Although, there is one extra cervical nerve root (C8). For the cervical region, the nerve root has the same name as the bottom vertebrae. For example, the nerve root exiting between the C3 and C4 vertebrae, would be the C4 nerve root. Since there is an extra cervical nerve root called C8, the pattern change for the rest of the spine. From T1 all the way to S5, the nerve root is the same as the top vertebrae. For example, the nerve root exiting between the T5 and T6 vertebrae is the T5 nerve root.
Why is it important to understand the spine?
The make-up of the spine is very complex. Understanding the spine is important to understanding a lot of different injuries, and where pain may be coming from. Common injuries treated by physical therapists include disc herniations, or “low back pain”. Now when you hear these terms, you have a better idea of what is actually happening in your back.
With a disc herniation, the danger is that the jelly nucleus pulposus is going to leak out and push on the nerve roots. When it does this, it irritates those nerve roots and can cause pain at that very spot on the back, or all the way to wherever their nerve root was sending it’s bit of information.
Degenerative Disc Disease:
You might have heard family members or elderly having “degenerative disc disease” this means that the soft padding between your bony vertebrae is getting really small. So, when these patients perform certain activities the vertebrae don’t have any pillow-like cushioning between the vertebrae. This can be painful! The important thing to understand about the spine is it serves many purposes. One of it’s most important purposes is that it is the center point of communication between the whole body and the brain, so any damage that occurs at the spine, can cause any variety of motor (movement) or sensory (temperature and touch/pressure) problems, as well as pain like you would have from any other normal injury.
If you are feeling any symptoms such as numbness, or tingling, or shooting pains down any of your limbs, this is caused by a problem at your spine. Also, if you feel any pain at a specific area of your back of neck, this is related to your vertebrae and it’s discs. Because of the complexity of your spine, it is very important to see a physical therapist who can get your body back to movement without pain. At Symmetry Physical Therapy, we have many tools to work out the problems surrounding your spine!