The T1 vertebra is the first (uppermost) of the twelve (12) thoracic vertebrae that make up the central and largest section of the spinal column between the lumbar vertebrae below and the cervical vertebrae above. While larger than the C7 vertebra above it, the T1 is the smallest of the thoracic vertebrae. It makes the transition from the cervical vertebrae of the neck to the thoracic vertebrae of the torso. As such, the T1 is somewhat distinct from the other thoracic vertebrae in better resembling the C7 cervical vertebra. It has a fairly cylindrical and broader centrum or ventral body with a concave upper surface, long transverse processes, and a larger, nearly horizontal spinous process. Otherwise, it is entirely like the T2-T9 vertebrae, which are often grouped together. The T1 helps support and articulate the first rib and second rib on each side of the body with a demi-facet on the lower portion for the second rib and a complete articular facet atop the exterior of the centrum where the first rib’s head connects.