The annulus fibrosis is the outer protective covering of the soft nucleus pulposus at the center of the spinal disc. This covering is composed of mainly ligament fiber rings that are tough. It connects the spinal vertebrae above and below each disc and prevents the nucleus pulposus from leaking out over the disc. This leakage is often called disc herniation, an injury which can often cause chronic pain.
Nucleus pulposus is a gel-like fluid found in the center of the spinal discs. The fluid acts as a lubricant and cushion for the vertebrae of the spine. Collagen, water and keratin make up the nucleus pulposus, allowing a person's spine to absorb daily shocks from walking, jumping and more without pain. This shock absorption begins to deteriorate over time, sometimes resulting in chronic back pain. A herniated disc occurs when this fluid bulges against, or even leaks out through, the annulus fibrosis and moves the vertebrae out of alignment, causing pressure on the surrounding vertebrae and nerve tissue.
Disc herniation is also commonly referred to as a torn, ruptured or slipped disc. As adults get older, they are usually more susceptible to this, but it can actually occur in a person of any age. Any herniation may cause pain in the spine both at the point of the tear and possibly in other areas of the body. Pressure on any spinal nerve from a herniated disc may cause pain in the area of the body with which the particular nerve is associated. This means pain in a person's foot may seem completely unrelated to their back, but because the nerve area associated with their feet is being pressed on by a herniated disc, the two are indeed connected.
Those who exercise moderately on a regular basis and ensure their spines are aligned while they sleep are usually less likely to experience tears or weakness in the annulus fibrosis. It is also generally a good idea to avoid putting undue pressure on the lower back. Things like maintaining poor posture and improperly lifting objects put additional pressure on the spine and can sometimes cause tears in the annulus fibrosis.
In order to identify a herniated disc properly, a specialist can scan the vertebrae for bulges or tears in the annulus fibrosis. Not all herniated discs are permanent injuries, and judging by the severity of damage to the nucleus pulposus, a patient may only require rest and anti-inflammatory prescriptions. Sometimes in more serious cases, manually moving the disc back into alignment or even performing surgery is required.