The Anatomy of a Spinal Disc

Spinal Discs, we talk about them all the time – but do you know what they even look like? Nothing complicated this week, let’s just learn about spinal discs!

What are Spinal Discs?

The discs of the spine are some of the hardest working players in the body.

In fact, they’re a great deal like the waterbed that serves as both an impromptu child’s trampoline and a place to get some much needed rest. Our spinal discs are tasked with standing up to the physical stress of our day to day activities, and are so important because together they allow our spine to move in all directions.

Doing what we can to keep them healthy is crucially important to our spinal health, and to better understand how we can do just that it helps to understand the anatomy of a spinal disc. Think of your spinal discs as the tiny but mighty cushions that sit between each pair of the 24 moveable bones (vertebrae) in your spine. In addition to cushioning the bones, each acts a small swivel that allows your body to tilt and rotate.

Maintaining the health of our spinal discs is one of the best things we can do to help minimize our risk of living with chronic neck or back pain.

Let’s dive in for a closer look at the anatomy of a spinal disc.


The Basic Anatomy of a Spinal Disc

There are 23 discs to be exact – 6 in the neck, 12 in the mid-back, and 5 in the lower back. The average size of a spinal disc is about one inch in thickness and can vary in color from light yellow to dark brown.

As we mentioned earlier, they allow the spine to be flexible and also serve as its “shock absorbers,” helping to cushion the bones of the spine and keep them from grinding together.

When we break down the fundamental anatomy of a spinal disc, we know that each disc is made up of three core components: an outer layer, inner layer, and a pair of endplates that help hold the discs in place between each pair of vertebrae.

The tough, fibrous outer layer is referred to as the annulus fibrosus, and the jelly-like inner layer, the nucleus pulposus.

The nucleus pulposus helps to absorb shock and distribute pressure while the annulus fibrosus provides stability to the spine.

The relationship between these two layers can be compared to a waterbed. The tough outer layer contains and protects the softer inside layer, which is mostly made up of – you guessed it  – water.

And it’s the high water content of each disc that helps keep them supple and moveable.

However, as we get older, our spinal discs tend to gradually lose fluid, causing them to stiffen.

That, in turn, can mean our discs become more prone to inflammation.

Additionally – as you may have also guessed from knowing what you now know about the anatomy of a spinal disc – they can actually start to shrink which can lead to compression of the nerves running through the spine and some potentially painful symptoms.

The importance of keeping our spinal discs healthy really can’t be overstated enough!


Keeping Discs healthy

The good news? There’s good news!

Simple movement is actually one of the best ways to keep your spinal discs healthy.

One thing we know from looking at the anatomy of a spinal disc is that they don’t have a particularly good blood supply.

Movement is how they bring in nutrients, and it’s those nutrients that help the discs stay healthy and push out waste that can contribute to the development of pain and inflammation.

So, make it a point to move more each day however you can – there’s no wrong way to do it!

And if your neck or back hurts, take 5 minutes for yourself, book an appointment, and let us know.




Blog by / February 8, 2023 / Blog

Dr. Paul Irvine is a doctor of chiropractic who graduated in 1994 with a Bachelor of Science degree from the University of NSW and in 1996, attained his Master of Chiropractic degree from Macquarie University in Australia. He practised in North Sydney for 5 years before he left Australia to travel and practise in the UK. He joined Complete Chiropractic in 2003 (est 1999) and took over the clinic in 2007