Final answer:
The thoracic spine consists of twelve vertebrae, numbered T1 to T12, located in the upper back region of the vertebral column. These vertebrae are responsible for rib attachment and contribute to the thoracic curve's stability, which is a primary curvature of the spine.
Step-by-step explanation:
The thoracic spine is comprised of twelve vertebrae, which are sequentially numbered from T1 to T12. These vertebrae are situated in the thoracic region, or upper back, of the vertebral column—an integral part of the human skeletal system. The thoracic vertebrae provide attachment points for the ribs and play a vital role in the overall structure and protection of the thoracic cavity.
Additionally, Figure 7.26 highlights that a typical thoracic vertebra features a long spinous process that has a pronounced downward angle, designed to overlap with the vertebra beneath it. These structural features are significant because they allow for the articulation with ribs and limit the range of motion in the thoracic spine, ensuring the stability of the upper back.
The vertebral column is subdivided into several regions, with 24 vertebrae in total, plus the fused bones of the sacrum and coccyx. The thoracic vertebrae, along with the cervical and lumbar regions, contribute to the natural curves of the spine, which enhance the spine's strength and flexibility.