Synonyms
Thoracic spine, BWS, thoracic spine
Introduction
The thoracic vertebrae belong to the human spine, beginning below the seventh cervical vertebra and ending at the lumbar spine. Mammals have a total of twelve thoracic vertebrae, which are also numbered Th1 to Th12. Th here stands for the Latin term pars thoracica “chest part” of thorax thorax.
Together with the ribs they are involved in the construction of the thorax. In general, the thoracic thoracic spine follows the structure of all vertebral bodies and serves as the base and origin of some muscles. The physiological shape of the thoracic spine is called kyphosis, which is a backward convex curvature of the spine in the lateral view of the body.
Structure
All vertebrae of the spine have the same construction principle. They have a vertebral body (lat. Corpus vertebrae) and a vertebral arch (lat.
Arcus vertebrae). From the vertebral body, lateral and rearward projections emerge. The transverse processes (Processus transversi) are laterally descending and the spinous processes (Processus spinosi) are moving backwards.
The spinous processes overlap like roof tiles and can be felt well on the back. The connection between vertebral arch and vertebral body is formed by the vertebral hole (Foramen vertebrale). The successive vertebral holes together form the spinal canal (lat.
Canalis vertebralis), which contains the spinal cord with its vessels, nerves and sheaths. An intervertebral hole is formed between two vertebrae, allowing the passage of the respective spinal nerve. The Pediculi arcus vertebrae, vertebral arches, define the bony boundaries.
The size of the individual thoracic vertebrae increases from head to tail. The shape as well as the alignment of the joint surfaces also differ depending on the height of the thoracic spine. There are a total of six articular surfaces per thoracic vertebra.
Two articular processes to the upper vertebra, two to the lower vertebra (lat. Processus articularis superior et inferior) and two articular surfaces to the ribs (lat. Facies costalis). – First cervical vertebra (carrier) – Atlas
- Second cervical vertebra (rotation) – Axis
- Seventh cervical vertebra – Vertebra prominens
- First thoracic vertebra – Vertebra thoracica I
- Twelfth thoracic vertebra – Vertebra thoracica XII
- …
Special features
The individual sections of the spinal column differ in shape and size. Particularly noteworthy is the shape of the vertebral holes, which are almost round in the chest area and have the smallest diameter between Th 5 and 6 in contrast to the cervical and lumbar spine. Here the vertebral holes are arranged triangularly.
As already mentioned, the thoracic spine forms a convex curvature to the rear, the kyphosis. The other areas of the spine form the opposite: lordosis. The rib-vertebral joint is also a special feature.
The articular cavities (foveae costales superior et inferior) of two thoracic vertebrae above or below each other accommodate the rib head. Only the first, eleventh and twelfth ribs are excluded from this, since they are only connected to one thoracic vertebra. In addition, the lateral transverse process of the first to tenth thoracic vertebrae forms a joint surface which is connected to the rib hump (lat.
Tubercula costae). The eleventh and twelfth thoracic vertebrae do not form this articular surface. Like the lumbar spine, the last thoracic vertebra has a transversal process (= transverse process) with a mamillary process (teat process) and an accessorius process (the additional process). In addition, the rib-vertebral joint is stabilized by numerous ligaments.
