how many intervertebral discs are there

How many intervertebral discs are in the lumbar spine?

The lumbar spine contains a total of 5 intervertebral discs situated between the vertebral bodies. The primary functions of these discs are to 1: Learn how the lumbar spinal discs function and how lower back conditions can cause back pain and/or radiating pain.

How many cervical discs are in the human body?

There are 23 total discs in the entire spinal column, and 6 of them are in the cervical spine. Each cervical disc rests between the cervical vertebrae, acts as a shock absorber in the cervical spine, and enables the neck to handle various stresses and loads. Save.

What is the function of intervertebral disc?

Intervertebral disk. An intervertebral disk acts as shock absorber between each of the vertebrae in the spinal column by keeping the vertebrae separated when there is impact from activity. They also serve to protect the nerves that run down the middle of the spine and intervertebral disks.

What is the intervertebral disk made of?

Intervertebral disk. The outside of the disk is made of a strong material called the annulus fibrosus. Inside this protective covering is a jelly-like substance known as mucoprotein gel. This interior is known as the nucleus pulposus. As the spine receives pressure, the gel moves inside the annulus fibrosus and redistributes itself to absorb...

How many intervertebral are there?

The average person is born with 33 individual bones (the vertebrae) that interact and connect with each other through flexible joints called facets. By the time a person becomes an adult most have only 24 vertebrae because some vertebrae at the bottom end of the spine fuse together during normal growth and development.

How are intervertebral discs numbered?

The bone numbering starts at the top, near the skull, with C1 and then each bone going down is given a higher number with the last bone in the neck called C7. Between those bones are discs, each given two numbers that coorespond to the bone above and below the disc. The disc located between C4 and C5 is called C4-C5.

How many intervertebral discs are in the vertebral column?

23 vertebral discsThere are a total of 23 vertebral discs in the spinal column. Specific problems with any of these discs may prompt unique symptoms, including pain that originates in the disc itself and/or pain that is related to the disc pressing on a nearby nerve.

How many parts are there in the intervertebral disc?

The intervertebral disc is made up of two components: the annulus fibrosus and thenucleus pulposus. The annulus fibrosus is the outer portion of the disc.

What are the 33 vertebrae?

The spine is composed of 33 bones, called vertebrae, divided into five sections: the cervical, thoracic, and lumbar spine sections, and the sacrum and coccyx bones. The cervical section of the spine is made up of the top seven vertebrae in the spine, C1 to C7, and is connected to the base of the skull.

How many discs are in the human neck?

Disks in the cervical spine A total of six disks are positioned between the seven cervical vertebrae (one between two vertebrae). In addition to cushioning against stresses placed on your neck, the disks allow you to flex and rotate your head more easily during activity.

What are the 26 bones of the spine called?

Your spine is a column of bones running down the back of your body. Without it, you couldn't hold up your head and body, or make any kind of movement. It consists of 26 bones called vertebrae.

What are intervertebral discs?

The vertebral column provides protection to the spinal cord that runs through its central cavity. Between each vertebra is an intervertebral disk. The disks are filled with a gelatinous substance, called the nucleus pulposus, which provides cushioning to the spinal column.

What are the two parts of the intervertebral disc?

Each disc is made up of two parts: the annulus fibrosus and the nucleus pulposus.Annulus Fibrosis. The annulus is a sturdy tire-like structure that encases a gel-like center, the nucleus pulposus. ... Nucleus Pulposus. The center portion of each intervertebral disc is a filled with a gel-like elastic substance. ... Endplates.

How many lumbar vertebrae are there?

Five vertebraeLumbar (lower back): Five vertebrae (L1 to L5) make up the lower part of the spine. Your lumbar spine supports the upper parts of the spine. It connects to the pelvis and bears most of your body's weight, as well as the stress of lifting and carrying items. Many back problems occur in the lumbar spine.

How are thoracic vertebrae 11 and 12 different from the other vertebrae?

How are thoracic vertebrae 11 and 12 different from the other vertebrae? The transverse processes do not have facets that articulate with the tubercles of the ribs.

What are the names of the discs in your back?

Spinal Discs are in Between Each Vertebra Spinal discs are located in between each of the vertebral bodies along the back bone and may also be referred to as an intervertebral disc, spinal disc, or disk. Each disc is named according to which two vertebral bodies it lies between.

Why is there no intervertebral disc between C1 and C2?

The second cervical vertebra, C2, is called the axis. It does contain a vertebral body and also contains a peg-like process called the dens which projects up and articulates with the atlas so there is no intervertebral disc between C1 and C2.

Where Are discs C4 and C5?

The C4 and C5 vertebrae are the primary members of the mid-cervical spine. These two members are the most mobile in the mid-neck, and they support most of the forward and backward movements of this section of the neck. Therefore, they are prone to motion-related injury and disorders like disc herniation.

Is there a disk between C1 and C2?

There is no intervertebral disc between C1 and C2, which is unique in the spine.

What is the correct order for the vertebral regions from superior to inferior?

From superior to inferior, these are: Cervical: 7 vertebrae (C1 = highest; C7 = lowest) Thoracic: 12 vertebrae (T1 = highest; T12 = lowest) Lumbar: 5 vertebrae (L1 = highest; L5 = lowest)

How many disks are there in the human spine?

They also serve to protect the nerves that run down the middle of the spine and intervertebral disks. There are a total of 24 disks in the human spine. The disks are made of fibrocartilaginous material. The outside of the disk is made of a strong material called the annulus fibrosus.

What is the role of the intervertebral disk?

An intervertebral disk acts as shock absorber between each of the vertebrae in the spinal column by keeping the vertebrae separated when there is impact from activity. They also serve to protect the nerves that run down the middle of the spine and intervertebral disks.

What is the inner covering of the spine?

Inside this protective covering is a jelly-like substance known as mucoprotein gel. This interior is known as the nucleus pulposus. As the spine receives pressure, the gel moves inside the annulus fibrosus and redistributes itself to absorb the impact of the pressure.

How many discs are there between vertebrae?

There is one disc between each pair of vertebrae, except for the first cervical segment, the atlas. The atlas is a ring around the roughly cone-shaped extension of the axis (second cervical segment). The axis acts as a post around which the atlas can rotate, allowing the neck to swivel.

What is the intervertebral disc?

Anatomical terminology. An intervertebral disc (or intervertebral fibrocartilage) lies between adjacent vertebrae in the vertebral column. Each disc forms a fibrocartilaginous joint (a symphysis ), to allow slight movement of the vertebrae, to act as a ligament to hold the vertebrae together, and to function as a shock absorber for the spine.

What is the micrograph of an intervertebral disc?

Micrograph showing a fragment of an intervertebral disc demonstrating degenerative fibrocartilage with loss of nuclei and nests of chondrocytes, as seen in degenerative disc disease. HPS stain.

What is the structure of the Cervical vertebra?

Structure. Cervical vertebra with intervertebral disc. Intervertebral discs consist of an outer fibrous ring, the anulus fibrosus disci intervertebralis, which surrounds an inner gel-like center, the nucleus pulposus. The anulus fibrosus consists of several layers (laminae) of fibrocartilage made up of both type I and type II collagen.

What is discogenic pain?

Anything arising from the intervertebral disc may be termed discogenic in particular when referring to associated pain as discogenic pain.

What is a slipped disc?

A spinal disc herniation, commonly referred to as a slipped disc, can happen when unbalanced mechanical pressures substantially deform the anulus fibrosus, allowing part of the nucleus to obtrude. These events can occur during peak physical performance, during traumas, or as a result of chronic deterioration, typically accompanied with poor posture and has been associated with a Propionbacterium acnes infection. Both the deformed anulus and the gel-like material of the nucleus pulposus can be forced laterally or posteriorly, distorting local muscle function and putting pressure on the nearby nerve. This can give the symptoms typical of nerve root entrapment. These symptoms can vary between paresthesia, numbness, chronic and/or acute pain, either locally or along the dermatome served by the entrapped nerve, loss of muscle tone and decreased homeostatic performance . The disc is not physically slipped; it bulges, usually in just one direction. Risk of Cauda Equina.

What is the space between adjacent vertebrae?

Intervertebral disc space . The intervertebral disc space is typically defined on an X-ray photograph as the space between adjacent vertebrae. In healthy patients, this corresponds to the size of the intervertebral disc.

What is intervertebral disc ?

There are a total of 24 disks in the human spine. The disks are made of fibrocartilaginous material. The outside of the disk is made of a strong material called the annulus fibrosus. Inside this protective covering is a jelly-like substance known as mucoprotein gel.

What is the portion of the vertebral body to which the cartilaginous endplate is applied?

The portion of the vertebral body to which the cartilaginous endplate is applied is referred to as the vertebral endplate.

What is the endplate of the disc?

The endplate permits diffusion and provides the main source of nutrition for the disc. The hyaline endplate is also the last part of the disc to wear through during severe disc degeneration. Plates of cartilage that bind the disc to their respective vertebral bodies.

What is the rim of the vertebral body called?

Each endplate covers almost the entire surface of the adjacent vertebral body; only a narrow rim of bone, called the ring apophysis, around the perimeter of the vertebral body is left uncovered by cartilage.

What is the difference between AF and collagen?

The AF contains an inner and an outer portion. They differ primarily in their collagen composition. While both are primarily collagen, the outer annulus contains mostly type I collagen, while the inner has predominantly type II. The inner annulus also contains more proteoglycans than the inner. NB collagen Type I: skin, tendon, vasculature, organs, bone (the main component of the organic part of bone) Type II: cartilage (the main collagenous component of cartilage and is more flexible)

Which ligament covers the posterior aspect of the vertebral bodies?

The posterior longitudinal ligament covers the posterior aspect of the vertebral bodies, within the vertebral canal, and serves mainly to prevent a posterior herniation of the intervertebral discs, and is therefore responsible for the most herniations being in the postero-lateral direction

Where is the disc innervated?

The disc is innervated in the outer few millimetres of the annulus fibrosus .

What are the intervertebral discs?

The intervertebral discs are fibrocartilaginous cushions serving as the spin e's shock absorbing system , which protect the vertebrae, brain, and other structures (i.e. nerves). The discs allow some vertebral motion: extension and flexion.

What are the two parts of the intervertebral disc?

Annulus Fibrosus and Nucleus Pulposus. Intervertebral discs are composed of an annulus fibrosus and a nucleus pulposus. Intervertebral discs are composed of an annulus fibrosus and a nucleus pulposus. Photo Courtesy of: SpineUniverse.com.

What part of the spinal column is the intervertebral disc?

The intervertebral discs make up one fourth of the spinal column's length. There are no discs between the Atlas (C1), Axis (C2), and Coccyx. Discs are not vascular and therefore depend on the end plates to diffuse needed nutrients. The cartilaginous layers of the end plates anchor the discs in place.

What is the difference between the nucleus and the annulus?

The difference is the concentration of these substances. The nucleus contains more water than the annulus.

What is the largest structure in the body without a vascular supply?

The intervertebral discs are the largest structures in the body without a vascular supply. By means of osmosis, each disc absorbs needed nutrients. Each disc is made up of two parts: the annulus fibrosus and the nucleus pulposus.

What is the annulus of the spine?

The annulus is a sturdy tire-like structure that encases a gel-like center, the nucleus pulposus. The annulus enhances the spine’s rotational stability and helps to resist compressive stress. The annulus is a layered structure consisting of water and sturdy elastic collagen fibers.

What is the intervertebral disc?

Understanding Spinal Anatomy: Intervertebral Discs. Between each vertebral body is a cushion called an intervertebral disc. Each disc absorbs the stress and shock the body incurs during movement and prevents the vertebrae from grinding against one another. The intervertebral discs are the largest structures in the body without a vascular supply. ...

Which structure in the body absorbs nutrients through osmosis?

The intervertebral discs are the largest structures in the body without a vascular supply. Through osmosis, each disc absorbs needed nutrients.

How many discs are there in the neck?

Watch Now. There are 6 intervertebral discs in the highly-mobile cervical spine. These cervical discs tend to be thinner than the lumbar discs in the lower back but thicker than the thoracic discs in the less-mobile upper back.

What is the transition region between a disc and the adjacent vertebra?

If a vertebral endplate becomes injured or dysfunctional, fewer nutrients can get to the disc, which may accelerate disc degeneration.

What happens to the cervical disc as you age?

With age, the cervical discs lose water, stiffen and become less flexible in adjusting to compression. Such degenerative changes may result in a herniated cervical disc, which is when the disc's inner core extrudes through its outer layer and comes in contact with the nerve root and/or spinal nerve.

What is the function of cervical discs?

Cervical discs support the neck’s vertebral bones while also enabling flexibility for head movements. Sitting between adjacent cervical vertebrae stacked atop each other, each cervical disc acts as a shock absorber to help the cervical spine handle various stresses and loads.

Why do cervical discs need to be hydrated?

The discs need to be well-hydrated in order to maintain their strength and softness to serve as the spine’s major carrier of axial load. With age, the cervical discs lose water, stiffen and become less flexible in adjusting to compression.

What is the inner core of a disc called?

The annulus fibrosus also distributes the forces placed on the structure. Inner core. This soft jelly interior, called the nucleus pulposus, is a loose, fibrous network suspended in mucoprotein gel that is sealed by the annulus fibrosus. The nucleus pulposus helps to provide cushioning and flexibility to the disc.

What is the outer layer of the cervical disc?

Cervical Disc Anatomy. Each cervical disc has 2 basic components: Outer layer. This tough exterior, called the annulus fibrosus , is comprised of collagen fibers that surround and protect the inner core. The annulus fibrosus also distributes the forces placed on the structure.

What is the endplate of the disc?

A bi-layered vertebral endplate made of cortical bone and hyaline cartilage is attached to the upper and lower surfaces of the disc and binds the disc to the vertebral body . The bony portion of the endplate is attached to the vertebral body and helps resist compressive loads on the spine. The cartilaginous portion of the endplate helps contain the annulus fibrosus and nucleus pulposus within their normal anatomic borders. 1

What is the composition of lumbar discs?

The lumbar disc typically consists of 1: Annulus fibrosus. The outer shell of a lumbar disc is called the annulus fibrosus.

What are the characteristics of lumbar discs?

The lumbar intervertebral discs have the following distinguishing features 2: Size. The lumbar intervertebral discs are the thickest compared to other spinal regions . The discs are also thicker in front than the back.

Why do lumbar discs get shorter?

The lumbar discs become shorter during the day due to the weight of the upper body. It is estimated that sleeping for a minimum of 5 hours helps the discs regain their original shape. Shape. The form of the lumbar disc changes with movement.

What are the functions of discs?

The primary functions of these discs are to 1: Distribute compressive loads placed on the spine, providing shock absorption properties. Maintain the distance between the vertebral bodies during movement. Provide flexibility to the spine and prevent excessive movements.

How much water is in the nucleus pulposus?

The nucleus pulposus contains 70% to 90% of water and reaches its peak hydration between the ages of 20 to 30 years, following which, dehydration and degeneration begin to occur. As age advances, the discs may get calcified (deposition of calcium) and hardened, reducing their flexibility. 1. Read more about Spinal Discs.

How does the disc receive nutrition?

The disc receives a majority of its nutrition through these endplates by absorbing fluids (similar to the action of a sponge) during spinal movements. Excessive forces and high-pressure postures, such as prolonged standing and sitting, can inhibit disc nutrition. 1.

Overview

Structure

Intervertebral discs consist of an outer fibrous ring, the anulus fibrosus disci intervertebralis, which surrounds an inner gel-like center, the nucleus pulposus. The anulus fibrosus consists of several layers (laminae) of fibrocartilage made up of both type I and type II collagen. Type I is concentrated toward the edge of the ring, where it provides greater strength. The stiff laminae can withstand compressive forces. The fibrous intervertebral disc contains the nucleus pulposus an…

Function

Clinical significance

Etymology

See also

External links