A typical feature of thoracic veebrae

Typical Thoracic VeebraA. The body is hea-shaped with roughly the same measurements from side to side and anteroposteriorly. On each side, it bears two costal demifacets.B. The veebral foramen is comparatively small and circular.C. The veebral arch1. The pedicles are directed straight backward. The superior veebral notch is shallow, while the inferior veebral notch is deep and conspicuous.2. The laminae overlap each other from above.3. The superior aicular processes project upwards from the junction of the pedicles and laminae. The aicular facets are flat and are directed backward and a little laterally and upwards. This direction permits rotatory movements of the spine.4. The inferior aicular processes are fused to the laminae. Their aicular facets are directed forwards and slightly downwards and medially.5. The transverse processes are large and are directed laterally and backward from the junction of the pedicles and laminae. The anterior surface of each process bears a facet near its tip, for aiculation with the tubercle of the corresponding rib.In the upper six veebrae, the costal facets on the transverse processes are concave and face forwards and laterally. In lower six, the facets are flat and face upwards, laterally and slightly forwards.6. The spine is long and is directed downwards and backward. The fifth to ninth spines are the longest, more veical and overlap each other. The upper and lower spines are less oblique in direction.Ref: Chaurasia; Volume 1 Chapter 13; Bones and Joints of the Thorax