Our physicians will carefully walk you through each step of your care, but many patients find it helpful to have a general understanding of their neck and back before they arrive at the clinic. This section helps provide a basic overview of spinal anatomy, which will help define some of the terminology your physician may reference during your visit.
Small, interlocking bones called vertebrae comprise each of the four spinal regions (listed below). The spine is made up of 33 individual vertebrae, and those are numbered based on the region of the spine where they are located.
Each vertebra consists of a vertebral body for load-bearing, a vertebral arch to protect the spinal cord, and transverse processes for ligament attachment. The vertebrae in each region of the spinal column are sized and shaped in a way to serve specific purposes – allowing for a mix of stability, balance, flexibility and protection. Vertebrae are interconnected by facet joints that enable various levels of mobility.
The bones of your spine are cushioned by intervertebral discs. These discs act as vital “shock absorbers” to help reduce the effects of natural stresses placed on the spine during movement. They also serve as a sort of padded buffer between vertebrae to prevent bone-on-bone friction. Spinal discs are named based on the two vertebrae they lie between. For instance, the disc between the T1 and T2 vertebrae is called the T1-T2 disc.
Intervertebral discs are the adult body’s largest structures that lack a vascular supply, and they therefore absorb nutrients through osmosis. Each disc is made up of two parts. The annulus fibrosis (the outer fibrous ring) and the nucleus pulposus (the inner, gel-like center) make up each disc.
The cervical spine region is the area of the neck. It contains seven vertebrae – numbered C1-C7 from top to bottom – which enable flexible head movement, protect the spinal cord and brain stem and support the base of the skull.
The thoracic spine region is the next area of the spine below the neck nearest the chest. It contains 12 vertebrae – numbered T1-T12 from top to bottom and smallest to largest – which provide more stability because of their attachment to the rib cage and sternum. Thoracic vertebrae are larger than cervical vertebrae and have longer spinous processes. Many of the body’s vital organs are located near the thoracic region of the spine, which is stronger, more stable and less flexible in order to protect these organs.
The lumbar spine region is the area below the thoracic region but above the sacral (pelvic) region. It contains five large vertebrae – numbered L1-L5 – which support much of the body’s weight. Every aspect of the lumbar vertebrae is larger than those found in the cervical and thoracic regions. This spinal region features slightly more range of motion than the thoracic region, but considerably less than the cervical region.
The sacral spine region is located beneath the abdomen near the pelvis. It contains five vertebrae fused into a triangular shape – numbered S1-S5 – to form the sacrum. The sacrum fits between the two hip bones connecting the spine to the pelvis. Immediately below the sacrum are five additional bones, fused together to form the Coccyx (tailbone).
The spinal cord originates at the brain stem and travels down the vertebral column which protects it. Nerve roots originate at every level of vertebrae along the spinal cord and branch off throughout the body from there. Damage to vertebrae or discs may interact with these nerve roots to cause intense, localized pain or numbness in the back or radiating pain in other parts of the body, such as the neck, arm or leg.