What are the typical Thoracic Vertebrae?

• A. T1-T4
• B. T2-T7
• C. T3-T9
• D. T2-T8

Answer: (C)

Typical thoracic vertebrae are the ones that show the standard rib-articulation pattern shared by most of the thoracic spine. They have costal facets on the bodies for the heads of the ribs and additional costal facets on the transverse processes for the rib tubercles, with the facets arranged in a consistent way. This pattern is seen most of the time between the second and eighth thoracic vertebrae, so those levels are considered the typical thoracic vertebrae. The vertebrae at the ends of the thoracic region—the first and the ninth through twelfth—are atypical because their rib-articulation features differ (for example, T1 has a full facet for rib 1 and demi-facets for rib 2, and the lower vertebrae lack or modify the transverse costal facets). Therefore, the common middle range, T2 through T8, represents the typical thoracic vertebrae.