All Topics  
Intervertebral disc

 

 
   Email Print
   Bookmark   Link
 

 

Intervertebral disc
 
 
  Topics Intervertebral disc Topic Home

Intervertebral discs (or intervertebral fibrocartilage) lie between adjacent vertebrae
Vertebra

A vertebra is an individual bone in the flexible column that defines vertebrate animals. The vertebral column encases and protects the spinal cord, which runs from the base of the cranium down the dorsal side of the animal until reaching the pelvis....
 in the spine
Vertebral column

In human anatomy, the vertebral column is a column of 24 vertebrae, the sacrum, intervertebral discs, and the coccyx situated in the dorsum aspect of the torso, separated by spinal discs....
. Each disc forms a cartilaginous joint
Joint

A joint is the location at which two or more bones make contact. They are constructed to allow movement and provide mechanical support, and are classified structurally and functionally....
 to allow slight movement of the vertebrae, and acts as a ligament
Ligament

Ligaments connect bone to bone. In anatomy, the term ligament is used to denote three different types of structures:# Fibrous Tissue that connects bones to other bones....
 to hold the vertebrae together.

s consist of an outer annulus fibrosus
Annulus fibrosus disci intervertebralis

Each intervertebral fibrocartilage is composed, at its circumference, of lamin? of fibrous tissue and fibrocartilage, forming the annulus fibrosus....
, which surrounds the inner nucleus pulposus
Nucleus pulposus

Nucleus pulposus is the jelly-like substance in the middle of the spinal disc. It is the remnant of the notochord. It functions to distribute hydraulic pressure in all directions within each Annulus fibrosus disci intervertebralis under compressive loads....
. The annulus fibrosus consists of several layers of fibrocartilage
Fibrocartilage

White fibrocartilage consists of a mixture of white fibrous tissue and cartilaginous tissue in various proportions; to the former of these constituents it owes its flexibility and toughness, and to the latter its elasticity....
. The strong annular fibers contain the nucleus pulposus and distribute pressure evenly across the disc.






Discussion
Ask a question about 'Intervertebral disc'
Start a new discussion about 'Intervertebral disc'
Answer questions from other users
Full Discussion Forum



Encyclopedia


Intervertebral discs (or intervertebral fibrocartilage) lie between adjacent vertebrae
Vertebra

A vertebra is an individual bone in the flexible column that defines vertebrate animals. The vertebral column encases and protects the spinal cord, which runs from the base of the cranium down the dorsal side of the animal until reaching the pelvis....
 in the spine
Vertebral column

In human anatomy, the vertebral column is a column of 24 vertebrae, the sacrum, intervertebral discs, and the coccyx situated in the dorsum aspect of the torso, separated by spinal discs....
. Each disc forms a cartilaginous joint
Joint

A joint is the location at which two or more bones make contact. They are constructed to allow movement and provide mechanical support, and are classified structurally and functionally....
 to allow slight movement of the vertebrae, and acts as a ligament
Ligament

Ligaments connect bone to bone. In anatomy, the term ligament is used to denote three different types of structures:# Fibrous Tissue that connects bones to other bones....
 to hold the vertebrae together.

Structure

Discs consist of an outer annulus fibrosus
Annulus fibrosus disci intervertebralis

Each intervertebral fibrocartilage is composed, at its circumference, of lamin? of fibrous tissue and fibrocartilage, forming the annulus fibrosus....
, which surrounds the inner nucleus pulposus
Nucleus pulposus

Nucleus pulposus is the jelly-like substance in the middle of the spinal disc. It is the remnant of the notochord. It functions to distribute hydraulic pressure in all directions within each Annulus fibrosus disci intervertebralis under compressive loads....
. The annulus fibrosus consists of several layers of fibrocartilage
Fibrocartilage

White fibrocartilage consists of a mixture of white fibrous tissue and cartilaginous tissue in various proportions; to the former of these constituents it owes its flexibility and toughness, and to the latter its elasticity....
. The strong annular fibers contain the nucleus pulposus and distribute pressure evenly across the disc. The nucleus pulposus contains loose fibers suspended in a mucoprotein gel the consistency of jelly. The nucleus of the disc acts as a shock absorber, absorbing the impact of the body's daily activities and keeping the two vertebrae separated. The disc can be likened to a doughnut: whereby the annulus fibrosis is similar to the dough and the nucleus pulposis is the jelly. If one presses down on the front of the doughnut the jelly moves posteriorly or to the back. When one develops a prolapsed disc the jelly/ nucleus pulposis is forced out of the doughnut/ disc and may put pressure on the nerve located near the disc. This can give one the symptoms of sciatica
Sciatica

Sciatica is a set of symptoms including pain that may be caused by general compression and/or irritation of one of five nerve roots that give rise to the sciatic nerve, or by compression or irritation of the sciatic nerve itself....
.

There is one disc between each pair of vertebrae, except for the first cervical segment, the atlas
Atlas (anatomy)

In anatomy, the atlas is the topmost cervical vertebra of the spine .It is named for the Atlas of mythology, because it supports the globe of the head ....
. The atlas is a ring around the roughly cone-shaped extension of the axis
Axis (anatomy)

In anatomy, the second cervical vertebra of the vertebral column is named the axis or epistropheus.It forms the pivot upon which the first cervical vertebra , which carries the head , rotates....
 (second cervical segment). The axis acts as a post around which the atlas can rotate, allowing the neck to swivel. There are a total of twenty-three discs in the spine
Vertebral column

In human anatomy, the vertebral column is a column of 24 vertebrae, the sacrum, intervertebral discs, and the coccyx situated in the dorsum aspect of the torso, separated by spinal discs....
, which are most commonly identified by specifying the particular vertebrae they separate. For example, the disc between the fifth and sixth cervical vertabrae is designated "C5-6".

Medical conditions related to the intervertebral disc

As people age, the nucleus pulposus begins to dehydrate, which limits its ability to absorb shock. The annulus fibrosus gets weaker with age and begins to tear. While this may not cause pain in some people, in others one or both of these may cause chronic pain.

Pain due to the inability of the dehydrating nucleus pulposus to absorb shock is called axial pain or disc space pain. One generally refers to the gradual dehydration of the nucleus pulposus as degenerative disc disease
Degenerative disc disease

Degeneration of the intervertebral disc, which is often called "degenerative disc disease" of the vertebral column, is a condition that can be painful and can greatly affect the quality of one's life....
.

When the annulus fibrosus tears due to an injury or the aging process, the nucleus pulposus can begin to extrude through the tear. This is called disc herniation
Spinal disc herniation

A spinal disc herniation ', incorrectly called a "slipped disc", is a medical condition affecting the Vertebral column, in which a tear in the outer, fibrous ring of an intervertebral disc ' allows the soft, central portion to hernia....
. Near the posterior side of each disc, all along the spine, major spinal nerves extend out to different organs, tissues, extremities etc. It is very common for the herniated disc to press against these nerves (pinched nerve) causing radiating pain, numbness, tingling, and diminished strength and/or range of motion. In addition, the contact of the inner nuclear gel, which contains inflammatory proteins, with a nerve can also cause significant pain. Nerve-related pain is called radicular pain
Radicular pain

Radicular Pain, or Radiculitis, is pain "radiated" along the dermatomic area of a nerve due to inflammation or other irritation of the nerve root at its connection to the spinal column....
.

Herniated discs
Spinal disc herniation

A spinal disc herniation ', incorrectly called a "slipped disc", is a medical condition affecting the Vertebral column, in which a tear in the outer, fibrous ring of an intervertebral disc ' allows the soft, central portion to hernia....
 go by many names and these can mean different things to different medical professionals. A slipped disc, ruptured disc, or a bulging disc can all refer to the same medical condition.

Protrusions of the disc into the adjacent vertebra are known as Schmorl's nodes
Schmorl's nodes

Schmorl's nodes are protrusions of the cartilage of the intervertebral disc through the vertebral body endplate and into the adjacent vertebra. ...
.

See also

  • Back pain
    Back pain

    Back pain is pain felt in the Human back that usually originates from the muscles, nerves, bones, joints or other structures in the Vertebral column....
  • Sciatica
    Sciatica

    Sciatica is a set of symptoms including pain that may be caused by general compression and/or irritation of one of five nerve roots that give rise to the sciatic nerve, or by compression or irritation of the sciatic nerve itself....
  • Spinal disc herniation
    Spinal disc herniation

    A spinal disc herniation ', incorrectly called a "slipped disc", is a medical condition affecting the Vertebral column, in which a tear in the outer, fibrous ring of an intervertebral disc ' allows the soft, central portion to hernia....
  • Vertebral column
    Vertebral column

    In human anatomy, the vertebral column is a column of 24 vertebrae, the sacrum, intervertebral discs, and the coccyx situated in the dorsum aspect of the torso, separated by spinal discs....
  • Spinal stenosis
    Spinal stenosis

    Spinal stenosis is a medical condition in which the spinal canal narrows and compresses the spinal cord and nerves. This is usually due to the natural process of spinal degeneration that occurs with aging....


Additional images


External links