Thoracic Vertebrae
The spine is made up of three groups of bones called "vertebrae." The
twelve in the chest area are the "thoracic" vertebrae, which are larger
than those in the cervical region. They have long, pointed spinous
processes that slope downward, and have facets on the sides of their
bodies that join with ribs. Beginning with the third thoracic vertebra
and moving down, the bodies of these bones increase in size. This
reflects the stress placed on them by the increasing amounts of body
weight they bear.