Vertebra T1

The first thoracic vertebra (T1) is a unique structure that serves as a transition between the cervical and thoracic regions of the spine. Anatomically, T1 has several distinct features:

1. Vertebral Body: The vertebral body of T1 is more similar to that of the cervical vertebrae, being relatively small and rectangular in shape. It has a superior surface that articulates with the last cervical vertebra (C7) and an inferior surface that articulates with the second thoracic vertebra (T2).

2. Spinous Process: The spinous process of T1 is long and prominent, similar to the cervical vertebrae, and it projects posteriorly and slightly downward.

3. Transverse Processes: The transverse processes of T1 are robust and contain facets for articulation with the first pair of ribs. These facets are located on the anterior aspects of the transverse processes.

4. Laminae and Pedicles: The laminae of T1 are broad and thick, providing a strong structure for the attachment of muscles and ligaments. The pedicles are short and stout, connecting the vertebral body to the transverse processes.

5. Articular Facets: T1 has superior articular facets that face upward and backward, similar to the cervical vertebrae, and inferior articular facets that face downward and forward, aligning with the thoracic vertebrae below.

6. Foramina: The vertebral foramen of T1 is large and triangular, accommodating the spinal cord as it transitions from the cervical to the thoracic region.