There are twelve thoracic vertebrae and they are intermediate in size between the cervical and lumbar vertebrae; they increase in size going towards the lumbar vertebrae. They are distinguished by the presence of facets on the sides of the bodies for articulation with the heads of the ribs, as well as facets on the transverse processes of all, except the eleventh and twelfth, for articulation with the tubercles of the ribs. By convention, the human thoracic vertebrae are numbered T1–T12, with the first one (T1) located closest to the skull and the others going down the spine toward the lumbar region.
Each thoracic disc is comprised of the following:
- Outer layer (annulus fibrosus). This durable exterior of the disc is comprised of tough collagen fibers to help distribute major loads placed on the spine and protect the disc’s soft interior.
- Inner core (nucleus pulposus). This jelly-like interior is a loose network of fibers floating in a mucoprotein gel. The disc’s inner core provides more cushioning and movement between adjacent vertebrae than the outer layer.
Intervertebral discs are the largest structures in the human body that do not have blood vessels. A super-thin structure between the disc and vertebra, called a vertebral end plate, provides diffusion so that nutrients can get into the disc.
Common conditions of thoracic disc include:
- Thoracic Degenerative Disc Disease
- Thoracic Disc Herniation
- Thoracic Disc Prolapse
- Thoracic Disc Injury