What is Neck Anatomy?
The anatomy of the neck, or cervical spine, includes the spinal structure from C1 to C7. The cervical spine supports the skull and acts as the conduit for the spinal cord. The C1 vertebrae, known as the atlas bone, begins at the base of the skull. Together, C1 and C2 facilitate 50% of motion for the head. C7 is the last vertebrae in the neck and it connects to T1, which is the first vertebrae in the thoracic spine.
What Nerves Control Neck Muscles?
The nerves that control the neck muscles are located in the C1 and C2 vertebrae. Other parts of the body controlled by cervical nerves are:
- C3: Parts of the face and behind the head
- C4: Portions of shoulders and diaphragm
- C5: Upper body muscles such as the deltoids and biceps
- C6: Portions of shoulder, arm, wrist, and into the thumb
- C7: Further portions of the shoulder, arm, and the middle finger
What Do Spinal Discs in the Neck Do?
Spinal discs in the neck are positioned between two adjoining vertebrae and act as shock absorbers of the cervical spine. The outer circle of the disc is made of a strong collagen, which helps hold the spine together. The outer ring protects the soft tissue in the center of the disc. Healthy disc tissue is of a gel-like consistency and, under high pressure, provides the greatest degree of shock absorption to the neck. Together, the strong outer structure and the softer interior help facilitate range of motion in the neck.
What are the Vertebrae in the Neck?
The vertebrae of the neck are the smallest vertebrae of the spine and consist of seven bony rings between the base of the skull and the top of the thoracic spine. The cervical spine has a natural inward curve. The primary function of C1 and C2 is to support the skull and mobility. C3 through C7 are more similar to the vertebrae of the thoracic and lumbar spine. The anatomy of the vertebrae has several bony prominences which act as attachment sites for muscles and ligaments:
- Spinous processes – each vertebra has a spinous process which is centered posteriorly at the point of the arch.
- Transverse processes – each vertebra has two transverse processes which extend laterally and posteriorly from the vertebral body.
- Pedicles – connect the vertebral body to the transverse processes.
- Lamina – connect the transverse and spinous processes.
- Articular processes – form joints between one vertebra and its superior and inferior counterparts. The articular processes are located at the intersection of the lamina and pedicles.
What Causes Neck Pain?
Neck pain is classified as acute or chronic. Common causes of neck pain include:
- Normal wear and tear and degeneration
- Sudden trauma
- Repetitive motion due to athletic or work activity
- Overuse
- Poor sleeping position
- Unhealthy ergonomics
- Stress
- Muscle strain
Conditions such as arthritis, degenerative disc disease, or a disc herniation can be a source of neck pain. An acute injury or whiplash to the neck may cause tenderness and pain in the neck.