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Intervertebral discs are they jelly donuts?

Firstly lets get some myths out of the way. Human discs do not slip, they really aren’t “discs”, they are nothing like a Jelly (jam) donut or a rubber washer, they do not exist in isolation and are made up of connective tissues of a predominantly cartilaginous nature. Thus their form is determined by their function and the ability of their cellular components to secrete extracellular material. They are living adaptable structures blending from the bone and endplate cartilage, they are intimately connected to both, forming a solid matrix joint allowing motion and load/force transfer. They work functionally in conjunction with their zygapophyseal joints to produce motion and stability to the vertebral…

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  The Secret Life of Spinal Discs

The intervertebral discs are responsible for 25 percent of our spine’s overall length. Given that the average adult spine measures 24 to 28 inches, the intervertebral discs account for six to seven of those inches. In young individuals, the water-filled, gel-like nucleus pulposus and annulus fibrosis are both firm and flexible. However, by age 40 — earlier than any other connective tissue — the vertebral discs often begin showing degenerative changes.

 Intervertebral Discs: From Degeneration to Regeneration

Degenerative disc disease is one of the most common causes of back pain and sciatica, and most people over the age of 30 already have some degree though they may not show symptoms for many years. “The disc itself is not a homogeneous material, but rather a composite of at least three different materials that have three different ultrastructures and mechanical function,” says Dr. Chahine. “The central part of the tissue is the gelatinous nucleus pulposus that provides hydrostatic pressure support. The fluid in the disc is very important to its mechanical function. The outer part — the annulus fibrosus — is a dense collagenous tissue that provides integrity and prevents the tissue from expanding in the horizontal direction when you apply loading in the vertical direction.”

Articles of Interest

How Does the Intervertebral Disc Work?

A board-certified internal medicine physician discusses how the intervertebral discs of the spine work.

The Intervertebral Disc

The spinal discs lie between two vertebrae and therefore are designated as intervertebral discs. One can easily imagine these discs as very tough spacers, which have a very tough of laminated covering of firm connective tissue in close interweaved fibrous layers. This spacer is firmly connected with the vertebral bodies above and below it. To get an idea how tough the discs are, remember that power lifters can hold over 500 pounds above their heads. Every disc in the lumbar spine and most of the discs in the thoracic must be able to support that total weight to make this feat possible. This is done with very little bulging from the discs. If there was significant bulging these powerlifters would fold over in pain. The discs can also be thought of as inflated truck tires and once they begin to deflate, instability of what they are supporting begins.

Disc Structure & Function

Our intervertebral disc (discus intervertebralis) has a round-elliptical shape. It is located between all vertebrae from C2-C3 to L5-S1. In young people, it appears as a white, gelatinous, and translucent structure. Over the years, like all collagen structures, it adopts a more yellow-brown color and gradually loses its elasticity, flexibility, and resilience.

Does The Intervertebral Disc Adapt To Load?

Over the past few years there has been quite the debate amongst many in the scientific community as to the extent of which the spine has the ability to adapt. While it is commonly accepted that the vertebral bones have the ability to adapt and become stronger/more dense with correctly dosed loading (a reason why powerlifters/weightlifters commonly have the highest bone mineral density in the world) there are still many questions to be answered when it comes to the intervertebral discs (IVDs).

Intervertebral discs: what they are and what are the most common injuries

Intervertebral discs are flexible, gelatinous cushions that separate the vertebrae of the spine. In total, humans have 23 intervertebral discs, which are flexible and resistant in structure. Composed of 95% water, these discs require proper hydration to function, as water allows the disc to swell and become a stable structure to support any load. As they do not have their own vascular system, they are nourished through the entry and exit of fluids from nearby tissues.

Problems Affecting the Spinal Discs: What You Need to Know

The spine is an intricate structure composed of bones, muscles, and ligaments, pivotal in providing support and flexibility to the human body. Central to this function are the spinal discs, which act as shock absorbers between the vertebrae, allowing for smooth movements and helping bear the body’s weight. However, these discs can succumb to various issues, such as herniation, degeneration, and bulging, leading to discomfort and debilitating pain.

Spinal Discs

The vertebral disc in the spine is an interesting and unique structure. The discs throughout the spine have three primary functions: They act as a shock absorbers in the spine, positioned between each bony vertebra. They act as supporting structures that hold the vertebrae of the spine together. They are cartilaginous joints that allow for slight mobility in the spine.

Spine & Intervertebral Disc Anatomy

The healthy adult disc is essentially avascular and aneural except for at the periphery of the annulus, thus creating a hostile low oxygen and low pH environment for resident cells. Such cells rely on diffusion of substances across cartilaginous endplates for nutrients and metabolic exchange.

Understanding the Anatomy of an Intervertebral Disc

The spine is a remarkable structure that provides support, flexibility, and protection to the spinal cord and nerves. It’s hard to do anything really without engaging your spine. At the core of its mobility and shock absorption are the intervertebral discs—vital structures located between each vertebra that play an essential role in spine health.

What is an intervertebral disc?

The nucleus pulposus is a gel-like structure that sits at the center of the disc and accounts for much of the flexibility of the spine. It is made of ~75% of water and the remainder are proteins. The tougher outer annulus fibrosis provides structure and constraint, and is well innervated. Tears in this portion of the disc can result in marked pain and dysfunction, with resultant herniation of the nucleus pulposus. Injuries to the intervertebral disc are common, and can result in pain and compression of the adjacent nerves, resulting in radiating symptoms, numbness or tingling, and even weakness. Evaluation of the discs is best made with magnetic resonance imaging (MRI). Like most other ligaments in the body, injury to the intervertebral discs can be permanent.

Resources

5 Tips To Nourish You Intervertebral Discs

The intervertebral discs are the cushions between the vertebrae that make up our spine. They serve as shock absorbers and allow for the flexibility of the spine. However, they can become damaged or degenerate over time due to poor posture, lack of movement, or injury. This can lead to chronic pain and discomfort. The good news is that there are ways to nourish your intervertebral discs through movement.

Regenex

Intervertebral discs are fibrocartilage cushions located between the vertebrae of the spine, providing support, flexibility, and shock absorption. They act as crucial structures, enabling movement while preventing bone-on-bone contact and facilitating spinal stability.

Anatomy Standard

The intervertebral discs are the elastic ring-shaped structures connecting the bodies of the vertebrae. It constitutes 20–33% of the entire height of the vertebral column, a number that decrease with age and inevitable progressive disc degeneration.

Kenhub

The intervertebral discs, like other cartilages, have no blood supply. They form the largest structures in the body without their own blood vessels. During embryonic development, and at birth, they possess some vascular supply which terminate in their endplates and anulus fibrosus. However, those blood vessels quickly deteriorate leaving them with no direct blood supply during postnatal life and in adulthood. The nutrients they require are absorbed from circulating blood by means of osmosis.

Physiopedia

IVDs allow the spine to be flexible without sacrificing a great deal of strength. They also provide a shock-absorbing effect within the spine and prevent the vertebrae from grinding together. They consist of three major components: the inner, nucleus pulposus (NP), the outer, annulus (AF) and the cartilaginous endplates that anchor the discs to adjacent vertebrae.

Radiopaedia

Intervertebral discs form the articulations between adjacent vertebral bodies from C2 to S1, thus forming 23 in total (although segmentation variations are not uncommon). Together they account for ~25% of the total height of the vertebral column which decreases with age as disc height is lost through normal aging.

StatPearls

Adjacent vertebrae articulate through zygapophyseal joints between the respective superior and inferior facets of the vertebral articular processes as well as through the joints of the vertebral bodies. While the former serves to limit the spine’s range of motion, the latter increases it and provides the majority of the spine’s weight-bearing capacity