The dorsal (thoracic) spine forms the middle portion of the vertebral column extending below the seventh cervical vertebra to above the first lumbar vertebra. The dorsal spine is formed by twelve vertebral bodies.
The vertebrae forming the dorsal spine are unique in shape as they are the only vertebral bodies articulating with ribs.
The lumbar spine represents the mid-lower segment of the vertebral column and is composed of five adjacent vertebrae. They are convex anteriorly to form a lumbar lordosis. The lumbar spine facet joints allows limited movements and rotation.
The sacrum is the lower most segment of the vertebral column and also forms the posterior wall of the bony pelvis. The sacrum is formed by five fused sacral vertebrae.
This model shows the origin of ribs, few of the cervical spines and the sacroiliac joint. The minimal tilt seen is likely positional rather that pathological.
This 3D model was created from the file STS_036. The source CT scan used to create this model can be found here.