Vertebra T4

The thoracic vertebra T4 (4th thoracic vertebra) is part of the thoracic spine, with several distinct anatomical features:

1. Vertebral Body: The vertebral body of T4 is heart-shaped and larger than the cervical vertebrae but smaller than the lumbar vertebrae. It provides attachment points for the ribs.

2. Vertebral Arch: The vertebral arch consists of pedicles and laminae. The pedicles are short and project posteriorly from the vertebral body, while the laminae are broad and overlap with adjacent vertebrae.

3. Spinous Process: The spinous process of T4 is long, slender, and directed downward, overlapping the vertebra below. This feature is typical of the mid-thoracic vertebrae.

4. Transverse Processes: The transverse processes of T4 are robust and project laterally. They have costal facets for articulation with the tubercles of the ribs.

5. Articular Processes: The superior articular processes face posteriorly and slightly laterally, while the inferior articular processes face anteriorly and slightly medially. This orientation allows for limited rotation and flexion/extension movements.

6. Costal Facets: T4 has demifacets on the sides of its vertebral body for articulation with the heads of the fourth and fifth ribs. Additionally, the transverse processes have facets for articulation with the tubercles of the fourth ribs.

7. Vertebral Foramen: The vertebral foramen is circular and smaller than that of the cervical vertebrae, providing passage for the spinal cord.