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The Neck

Understanding the Cervical Spine

The cervical spine, upper 7 vertebrae of your spine that is most commonly referred to as the ‘neck’. The vertebrae of your spine are numbered, they start with the letter ‘C’ (short for cervical). The first two vertebrae, C1 and C2, are highly specialized and are given unique names: atlas and axis. The remaining vertebrae of your neck C3 through to C7 are more classic vertebrae, having a body, pedicles, laminae, spinous processes, and facet joints. These vertebrae support the skull, move the spine, and protect the spinal cord which is the bundle of nerves connected to the brain. There is a C8 but it is not a vertebrae, it the exit point of cervical nerves joining to the thoracic spine.

Discs

Discs are located in between the vertebrae of your spine. These discs are jelly like materials that cushion and stop the bones from rubbing on each other. If the discs move out of place, bulge, or leak they can cause a lot of pain. If they press on a nerve when they move out of place, the pain can be very severe. 

Muscles

Several muscles support the vertebrae of the neck. The major muscle involved is called the spinalis, this moves the spine and helps maintain correct posture. It is divided into three parts;

Spinalis cervicis: This muscle begins in the middle region of the spine (thoracic spine) and travels up to C2 (the axis). This muscle helps extend the neck.

Spinalis capitis: This muscle begins in 3 locations, the upper and middle thoracic spine as well as the lower cervical spine. It extends up to the base of the skull. This muscle relates to another muscle in the neck which is the semispinalis capitis.

The longus colli muscle: This is a broad muscle in the middle and it becomes narrow as it connects to the vertebrae. It helps move and stabilize the neck.

Tendons

Tendons are elastic tissues that connect muscles to bones. The tendons main role is to stabilize the vertebrae in your neck. The main tendons in your neck can be seen above, they attach to the muscles mentioned above to the vertebral discs.

Notice the colour of the tendons, they are white. Whereas muscles are red. The reason is due to blood flow, muscles have good blood flow, whereas tendons do not. The rotator cuff tendons require careful observation, since many of the tendons attach in a similar location it may sustain damage easily.

Ligaments

Many ligaments, or bands of connective tissue, wrap around the spinal column and connect its vertebrae (like “sticky” rubber-bands). These ligaments also prevent excessive movement that could damage the spinal column.

There are six major ligaments in the cervical spine, three of which are unique to the cervical spine.

  1. Nuchal ligament: A continuation of the supraspinous ligament. It attaches to the tips of C1-C7 and provides the attachment for the rhomboids and trapezius (top of your shoulder and neck).
  2. Transverse ligament of the atlas: Connects the lateral masses of the atlas (C1).
  3. Anterior longitudinal ligaments: Long ligaments located at the front that run the length of the vertebral column.
  4. Posterior longitudinal ligaments: Long ligaments located at the rear that run the length of the vertebral column.
  5. Ligamentum flavum: Connects the laminae of adjacent vertebrae.
  6. Interspinous ligament: Connects the spinous processes of adjacent vertebrae.

Cartilage

In the cervical spine facet joints are a key part of the spine’s flexibility. A facet joint is comprised of hard yet smooth cartilage on the upper and lower surfaces to protect the back part of vertebral bones. Cartilage is only located in the facet joints, not the discs. Cartilage also acts a shock absorber however, cartilage wears out and cannot repair itself.

Joint Capsule (lubrication membrane)

The capsule is a thick, fibrous structure that wraps around the facet joint. Inside the capsule is the synovial membrane which is lined by the synovium, a soft tissue that secretes synovial fluid and provides lubrication for the facet joints. The synovial fluid is both viscous and sticky lubricant. Synovial fluid is what allows us to flex our joints under great pressure without wear.

Nerves & Dermatomes

A dermatome is the area of the skin where we feel sensation that is based on a spinal sensory nerve root. These nerves start at a particular point and branch out the peripheral systems throughout our body. As we already know, nerves allow us to feel sensations such as burning, tingling, numbness, pressure, and more.

It is important to understand the anatomy of the spine, so we can become familiar with dermatomes. When we look in to the nerve roots from the spine, there are nerves at the front (anterior) as well as the back (posterior). The anterior nerve roots are responsible for motor signals to the body, and posterior nerve roots receive sensory signals like pain or other sensory symptoms.

There are specific dermatomes for each of these spinal nerves, except the first cervical spinal nerve. Dermatomes are used to represent the patterns of sensory nerves that cover various parts of the body.

In the cervical spine there are 7 dermatomes (C2-C8, as C1 nerve has no dermatome). For example, if an issue occurs in the C7 vertebrae and this creates pressure or inflammation on the posterior nerves, you may feel shooting pains or numbness in your middle finger.

C2 – Head and neck

C3 – Head and neck

C4 – Neck

C5 – Neck

C6 – Thumb

C7 – Middle finger

C8 – Little finger

 

Conditions of the Neck

Pathological Conditions of the Neck

Facet joint osteoarthritis:

Osteoarthritis is the most common form of arthritis, and often affects the facet joints. Caused by aging and wear and tear of cartilage, osteoarthritis symptoms may include pain, stiffness, and swelling. Osteoarthritis is not simple to understand, there are many links with the wear and tear of cartilage that also affects every other part of your joint. We discuss this in our treatment information pack.

Degenerative disc disease:

Degeneration that occurs as a part of the aging process not only affects cartilage in the facet joints, it also affects the discs that are in between the vertebrae. The jelly-like disc materials begin to fray, it can lead to compression of the disc as fluid leaks out. This creates pressure and inflammation around the nerves of the spine.

Issues that often occur with Osteoarthritis or Disc Degeneration

Disc bulge:

Degenerative and weakened discs can lead to jelly like fluid trying to escape the disc, this causes a ‘bulge’. It is similar to a car tyre that has developed an egg on the side wall.

Disc herniation:

Herniation is the process by which the jelly like material actually leaks out of the disc.

Nerve impingement:

Nerves of the spine can become compressed or impinged if discs are bulging/herniated. This can also occur due to spine canal stenosis which is narrowing of the spine canal where spinal fluid is maintained.

Tendonitis:

Inflammation of the tendons that are connecting muscle to bone. Tendonitis is very common. It can occur due to simple overuse, overstrain or even underuse. Tendons can become weak very quickly and they take a very long time to repair due to lack of blood flow.

ligament strain or tear: The ligaments of your neck can strain when one of the muscles supporting the shoulder, head or upper back joint is stretched beyond its limit. In severe cases this can lead to a tear, not just a strain.  If the ligaments are degenerate due to low activity, this will be more likely to tear.

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