Aging disc Featured Image (Final)

The Aging Disc – Everything you need to know

To understand the aging disc, you must understand the normal intervertebral disc. We know that the disc has an annulus fibrosus outside and a nucleus pulposus inside.

With aging, there is degeneration of the disc that will alter the function of the disc.

What is the function of the intervertebral disc?

It links the vertebral bodies together and is responsible for about 25% of the spinal column height.

It is a cushion between the vertebrae, so it allows spinal motion, but also provided stability.

 

Normal Intervertebral Disc Is Made of two components:

Aging Disc (Anulus fibrosus, Nucleus pulposus)

Annulus Fibrosus (outside part):

  • Has high collagen and low glycosaminoglycan (GAG) concentrations.
  • Collagen gives the disc its tensile strength.
  • The collagen is Type 1 collagen, the same collagen present in bones.
  • The annulus fibrosus is a hard outside structure that protects the nucleus pulposus.
  • The annulus fibrosus has a multi-layer laminar architecture made of Type 1 collagen.
  • Each successive layer is oriented at 30 degrees to the horizontal in the opposite direction, leading to a criss-cross type of pattern.
  • The composition allows the annulus fibrosus. Which has the highest tensile modulus to resist the torsion the axial, and the tensile loads.
  • The inner part of the annulus fibrosus has fibrocartilaginous tissue that gradually blends with the nucleus pulposus.
  • Posterolateral, the annulus fibrosus is thinner. Has disorganized collagen, and has a greater proportion of vertical fibers.
  • It is the weakest part of the annulus fibrosus and this area contributes to the majority of disc herniation.
  • The nucleus pulposus is the central part of the intervertebral disc.
  • This is the part that is surrounded and protected by the annulus fibrosus.
  • It has Type 2 collagen and also has proteoglycans and a large percentage of the water.

 

2. Nucleus Pulposus (Inside part):

  • High in glycosaminoglycans (GAG) and low in collagen content.
  • Because it is low in collagen, it is a soft structure that is good in compression.
  • It allows compressibility (allows the load to be placed on the spine).
  • The collagen is type 2 collagen, the same collagen present in cartilage. (gentler, softer collagen)
  • The annulus fibrosus has high collagen and a low proteoglycan ratio.
  • The nucleus pulposus has type 2 collagen and also has a lot of proteoglycans, and has a high percentage of water.
  • The hydrophilic nature of the proteoglycans will be responsible for the height of the intervertebral disc.
  • The molecule of the proteoglycan is responsible for the hydrophilic behavior of the nucleus pulposus and it contributes to most of its ability to maintain the hydrostatic pressure.
  • The proteoglycans constitute a low percentage of dry weight within the annulus fibrosus and a high percentage of dry weight within the nucleus pulposus, and it interacts with water to resist compression.

 

Within the functional spine unit, the nucleus pulposus function is to resist compressive loads.

We should know that pressure within the nucleus pulposus of an adult intervertebral disc is greatest when sitting unopposed and the lowest pressure is when lying supine.

The nucleus pulposus is elastic, so it has low collagen and a high proteoglycan ratio.

It also has chondrocyte-like cells that are responsible for producing Type 2 collagen and proteoglycans. We have to connect these cells to nutrition or blood supply.

 

What is the blood supply of the disc?

The intervertebral disc is an avascular structure in adults. The capillaries will terminate at the endplate.

The nucleus pulposus receives the majority of its nutrition from diffusion from the blood vessels within the endplates.

The annulus fibrosus is not porous enough to allow diffusion of the fluids.

The nutrients will come from the blood vessels at the margins of the disc and it has to go through the cartilaginous endplate to reach the disc cells.

blood supply of the disc

The blood supply to the endplate and outer annulus decreases with age and the cellular metabolism is affected by decreased nutrition.

With aging, there will be intervertebral disc degeneration and there will be decreased nutrition to the intervertebral disc due to decreased vascularity.

The nucleus pulposus of the intervertebral disc has chondrocyte-like cells that have a limited blood supply and it generates energy through anaerobic glycolysis.

The nucleus pulposus needs glucose because they obtain their energy through glycolysis, even in the absence of oxygen.

The disc cells do not need oxygen to remain alive, but they need glucose, so they die at a low glucose level or acidic ph.

The aging of the spinal column begins very early.

It can be slowed by permanent attention to maintaining the spinal curves (including during the most common activities of daily living)

Normal weight must be maintained throughout life.

 

For more information talk to a healthcare provider.

If you have any questions about Aging Disc please feel free and leave a comment.

Do share this blog with your friends and family!

 

 

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Spine Featured Image

Vertebral Column Anatomy

Your spine is also called your backbone or vertebral column is composed of 33 bones called vertebrae. Which provides your body with support and protects your spinal cord from injury.

The vertebrae can be divided into five group’s cervical, thoracic, lumbar, sacral, coccyx. Each of which has unique features suited to its functions there are

  • 7 Cervical vertebrae numbered C1 to C7.
  • 12 Thoracic vertebrae numbered T1to T12.
  • 5 Lumbar vertebrae numbered L1 to L5.
  • 5 Sacral vertebrae numbered S1 to S5.
  • Coccyx

The upper 24 vertebrae are articulating separated by intervertebral discs the sacral vertebra and the bones of the coccyx are fused.
The cervical vertebrae (neck) which are the vertebrae of your neck support your head. Which weighs around 10 to 13 pounds.
C1 and C2 are specialized Vertebrae,

  • Allow for the greatest range of motion of all the vertebrae
  • C1 is called “ATLAS”. Ring Shaped and attaches directly to your skull
  • C1 allows you to nod your head
  • C2 is called “AXIS”. Serves as an axis around which C1 pivots
  • C1 is able to pivot on C2 thanks to a specialized process called DENS, or ODONTOID process

The Thoracic vertebrae are the vertebrae of your mid and upper back. Hold the ribcage and protect your heart and lungs. They have a limited range of motion.

The Lumbar vertebrae are the vertebra of the lower back. Bear the weight of your upper body and are larger in order to support the stress. Especially when you lift something heavy.

The Sacral vertebrae connect your spine to your hip bones these vertebrae are fused together with your hip bones, they form the pelvic girdle.

The coccyx or tailbone is made up of four fused which provide an attachment point for ligaments and muscles of the pelvic floor.

Parts of a Vertebra:

A vertebra has three parts

  1. Body
  2. Vertebral arch
  3. Processes

Spine 2

The body bears weight, the vertebral arch houses, and the spinal cord and the processes allow for muscle attachment. The vertebral arch is made up of two supporting pedicles and two laminae.

Space inside which houses the spinal cord is called the vertebral foramen. Under each pedicle spinal nerves exit and pass through the intervertebral foramina.

Seven bony processors arise from each vertebral arch to form facet joints and processes for muscle attachment.

Facet joints allow for back motion each vertebra has two pairs of facet joints one pair connects to the vertebra above and one pair that connects to the vertebra below.

There is also a pair of transverse processes and a spinous process.

Between the vertebras are the intervertebral discs, which provide cushioning and prevent the bones from rubbing together.

Discs are composed of an annulus. Which is made up of several layers or lamina of fibrocartilage.

Criss-crossing fibrous bands attach between the bodies of the vertebrae above & below and a gel-filled center called the nucleus.

The nucleus distributes the pressure evenly within each disc during compression.

The nucleus is full of proteoglycans large molecules with sugar subunits that are very hydrophilic. This structure swells with water unless it experiences constraints from the surrounding tissues.

spine 3

Hence, the nucleus absorbs fluid at night or when you are lying down and then this fluid is pushed out during the days. When you are upright and pressure is applied to the intervertebral discs. We shorten as we age because the discs lose the ability to reabsorb fluid during rest and they flatten and become more brittle.

 

 

If you have any questions about Vertebral Column please feel free and leave a comment.

Do share this blog with your friends and family!

 

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Anatomy of the Spine

When encouraging or applauding someone, we always say keep it up. The spinal cord is the most important part of the human body. In fact, it is safe to say that the human body depends on this single particle. But as mentioned above, is it really possible for a person to live with a stiff spine? Let’s take a closer look at this blog.

The human spine is made up of three segments. These segments form three natural curves when viewed from the side. The c-shaped curves of the neck and the lower back, which is called the cervical spine and the lumbar spine respectively, and the reverse c-shaped curve of the chest is called the thoracic spine. Let’s understand the structure of the spine-

 

Vertebrae
The human spine is made up of small bones known as vertebrae. These are the bones, which are assembled on top of one another which creates the natural curves. The spinal cord and nerve roots get protected by these bones as they create a canal. There is a total of 7 cervical vertebrae, 12 thoracic vertebrae, and 5 lumbar vertebrae.

Spinal Cord and Nerves
The spinal cord travels through the middle part of each stacked vertebra, called the central canal which extends from the skull to your lower back. Nerves carry messages between the brain and muscles by branching out from the spinal cord through openings in the vertebrae.

Muscles and Ligaments
Muscles work to stabilize and support the spine. Also, the ligament keeps the spine in good shape and helps in coordination.

Intervertebral Disks
These sit in between the vertebrae. They are flat and round. These made up of two main components- Nucleus pulposus and Annulus fibrosus. These disks act as shock absorbers for the spine as they maintain the strength of the spine by expanding when required.

Facet Joints
There are small joints between the back of the vertebrae that help the human spine move. There are four facet joints associated with each vertebra. The facet joints are important as they allow rotation of the spine.

This is the anatomy of the spine. I hope this information adds value to your knowledge. Watch out this space for more such information. Greetings for SYS Medtech International PVT. LTD.

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