The 12 vertebrae of the thoracic spine represent the central portion of the spinal column, the bony tower that provides postural support for standing and sitting and also houses the spinal cord. The spinal cord is the fibrous band of nerves that extends from the brain down the back. The brain communicates with the body via the spinal cord and its branches. The thoracic spine curves away from the body at its top but returns inward before it ends.

The vertebrae of the thoracic spine are numbered T1 through T12. The “T” stands for “thoracic.” T1 is located just above the collarbone, and T12 is located in the small of the back where it curves in.

The thoracic vertebrae vary in size. The ones near the cervical spine are smaller, and those near the lumbar spine are bigger. The lowest thoracic vertebra, T12, is the largest within the thoracic spine.

Each thoracic vertebra has an indentation, or facet, at the top and bottom of its body, the largest part of the vertebra. The 12 pairs of rib bones extend from these indentations. Most of these curved flat ribs wrap around the body and connect to the chest bone, or sternum, via the coastal cartilage. The bottom three sets of ribs hang freely and do not connect in front.  

Between each vertebra is a rubbery pad that protects the vertebrae from grinding against one another and creates a small joint that makes movement possible. These pads are called intervertebral discs, and they absorb shocks and distribute pressure on each vertebra. These discs can become damaged through injury or deterioration, leading to a painful condition known as a herniated (or bulging) disc; in the worst cases, surgery is needed to alleviate the pain and debility.

Although the cervical vertebrae of the neck are more commonly injured, thoracic vertebrae can be fractured due to falls, car accidents, and blunt force trauma. Vertebral fracture can lead to paralysis and other long-term disabilities.