What Is the Nucleus Pulposus?
The nucleus pulposus is part of the intervertebral disc.
It is the soft filling located in the center of the disc.
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It is surrounded by a strong covering consisting of 3 concentric layers of tough fibrous tissue.
The covering is called the annulus fibrosus.
The intervertebral disc moves as you move.
The strong outer fibers of the annulus fibrosus package the nucleus pulposus and keep it safely inside.
Spinal Action
Your spinal movements are supported by your intervertebral disc.
And it’s the nucleus pulposus that allows the disc to be so moveable.
Many times per day, the repeated spinal actions of twisting, tilting, arching, rounding, etc.
Let’s take the example of bending forward to pick something up from the floor.
This action may involve a motion called forward spinal flexion, which is basically rounding over at the spine.
Disc Injury
With persistent or excessive spinal flexion, the disc may be pushed too far back.
If the fibers of the annulus fibrosus are weak ortorn, the nucleus pulposus may escape between them.
When it does, it may come into contact with the nearby spinal nerve root, causingpainand other symptoms.
This injury is called a herniated disc.
In young people, the nucleus pulposus is made mostly of water.
So for this age group, a herniation due to trauma is more likely than in older people.
But as we get older, the disc, especially the nucleus pulposus dries out.
In this case, the shock absorption function of the disc is, for the most part, lost.
A Word From Verywell
The near-liquid consistency of the nucleus fibrosis makes it responsive to movement.
But another one of its functions is to buoy the spine; this helps prevent pressure on the bones.
Many times, you might replace that particular movement by bending at your hips, knees, and ankles.
2021;14(3):402-407. doi:10.25122/jml-2021-1059
UCLA Health.Degenerative disc disease.
