Thoracic vertebrae

(A) T1 has a vertebral foramen and body similar to a cervical vertebra.
(B) T5-T9 vertebrae have typical characteristics of thoracic vertebrae.
(C) T12 has bony processes and a body size similar to a lumbar vertebra. The planes of the articular facets of thoracic vertebrae define an arc (red arrows) that centers on an axis traversing the vertebral bodies vertically.
(D) Superior and inferior costal facets (demifacets) on the vertebral body, costal facets on the transverse processes, and long sloping spinous processes are characteristic of thoracic vertebrae.