The spine consists of three vertebral columns, including the cervical vertebrae, lumbar vertebrae, and thoracic vertebrae. The cervical vertebrae are located in the neck. The lowest portion of the spine consists of the lumbar vertebrae. Between the cervical vertebrae and the lumbar vertebrae are the thoracic vertebrae. The 12 thoracic vertebrae are labeled T1 through T12, with T1 being closest to the skull and T12 being closest to the tailbone. The T5 is the fifth thoracic vertebra closest to the skull.

Most thoracic vertebrae have a variety of characteristics in common. The middle portions of these vertebrae are heart-shaped. The short, thick processes on the outer sides of the vertebrae, which are called the pedicles, are directed slightly upward. The laminae overlap the subjacent vertebrae, in much the same fashion as roof tiles overlap one another. When thoracic vertebrae are harmed, such as through compression or injury, severe pain results. The T4 and T5 vertebrae are the most commonly injured thoracic vertebrae.