Anatomy of the Spine
Your spine consists of a column of individual bones called vertebrae. Your vertebrae extend from the base of your skull to your tailbone. They vary in size and shape depending on where in the spine they are located.
Vertebrae are separated by intervertebral discs made of a soft material called collagen. Intervertebral discs act as shock absorbers, cradling your spinal vertebrae and allowing them to move and flex.
Segments of the Spine
The spine itself is divided into several segments.
The cervical spine consists of the seven vertebrae in your neck. Because of the great degree of flexibility here, the occurrence of arthritic conditions and disc disease is quite high.
The thoracic spine begins where the ribs insert into the vertebrae and ends at the bottom of the rib cage. It contains 12 vertebrae.
The lumbar spine consists of 5 or 6 vertebrae. The sacrum comprises the fused bones that attach to the bones of the hip. The final segment, the coccyx, is commonly known as the tailbone. The sacrum and coccyx usually contain no disc material.
Disorders of the Spine
Disorders of the spine can affect the vertebrae, the intervertebral discs, or the spinal cord and spinal nerves.
- Arthritis is the most common disease of the spine, and it affects the bony joints in the cervical and lumbar spinal segments.
- Stenosis is caused by overgrowth of vertebrae or ligaments and can cause the spinal cord or the nerves that exit the spinal cord to become compressed.
- A herniated disc describes an intervertebral disc that has been pushed out of its normal alignment. Herniated discs can cause pain or neurological symptoms when they exert pressure on the spinal cord or spinal nerves.
- Other disorders, including tumors and infections, can also affect the spine nearly anywhere.