Cervical Vertebrae Anatomy
Thoracic Vertebrae (T2 – T8)
Introduction to the Thoracic Vertebrae:
The twelve thoracic vertebrae make up the middle portion of the vertebral column. Above are the cervical vertebrae and below are the lumbar, sacral, and coccygeal vertebrae.
Each thoracic vertebra articulates with a pair of ribs at facets (or small depressions) on the vertebral bodies and transverse processes (except at T11 and T12).
Most of the thoracic vertebrae share various anatomical characteristics.
However, T1 somewhat resembles the last cervical vertebra (C7) and T9 – T12 progressively look more like the lumbar vertebrae.
- Body or centrum (corpus vertebrae) is a cylindrical mass on the anterior side of the vertebra. It articulates with vertebral bodies (or centrums) above and below.
- Vertebral foramen or spinal foramen (foramen vertebrale) is a large opening in the centre of the bone that forms a passageway for the spinal cord.
- Vertebral arch or neural arch (arcus vertebrae) is made up of two pedicles, two laminae, and a spinous process. The arch encloses the posterior vertebral foramen and protects the spinal cord.
- Pedicle of the vertebral arch (pediculus arcus vertebrae) is a posterior extension from the lateral side of the body. The two pedicles form the base of the vertebral arch (L., pediculus, a little foot stalk).
- Lamina of the vertebral arch (lamina arcus vertebrae) a plate of bone that extends from the pedicle. The two laminae form the dorsal portions of the vertebral arch.
- Spinous process (processus spinous) is a downward posterior projection from the junction of the two laminae. It is long and narrow and has an expanded (tuberculated) tip. Ligaments and muscles that move the vertebral column.
- Transverse process (processus transversus) is a thick, elongated projection that extends lateroposteriorly from the junction of the pedicle and lamina. It serves as an attachment point for several back muscles.
- Superior articular process (processus articularis superior) is the superior projection near the junction of the pedicle and lamina. The associated facet is flattened, faces backward, and articulates with the inferior articular facet on the vertebra above.
- Inferior articular process (processus articularis inferior) is an inferior projection from the anterior surface of the lamina. The associated facet is flattened, faces forward, and articulates with the superior articular facet on the vertebra below.
- Superior costal facet or superior costal fovea (fovea costalis superior) is a depression on the superiolateral surface of the vertebral body, posterior to the pedicle. The superior costal facet is a demifacet or partial facet. It aligns with the inferior costal facet on the vertebra above to form a complete facet for articulation with the head of a rib.
- Inferior costal facet or inferior costal fovea (fovea costalis inferior) is a depression on the inferiolateral surface of the vertebral body, anterior to the inferior vertebral notch. It is a demifacet that aligns with the superior costal facet on the vertebra above to form a complete facet for articulation with the head of a rib.
- Intervertebral disc (disci intervertebrales) is a thick pad of connective tissues that helps hold adjacent vertebrae together and acts as a shock absorber. It consists of an outer layer of fibrocartilage and an inner layer of gel-like substance called the nucleus pulposes.
- Superior vertebral notch (incisor vertebralis superior) is a slight indentation on the superior surface of the pedicle.
- Inferior vertebral notch (incisor vertebralis superior) is a slight indentation on the inferior surface of the pedicle.
- Intervertebral foramen (foramina intervertebrale) is a large lateral opening located between two adjacent vertebrae.
The opening is formed by the inferior vertebral notch on the vertebra above and the superior vertebral notch on the vertebra below. The opening, which is also called the neural foramen or lateral foramen, serves as a passageway for a spinal nerve and a pair of nerve roots.