- There are five lumbar vertebrae (singular: vertebra) in the abdominal region of the trunk.
- They are named L1-L5 from superior to inferior.
- They articulate with each other via paired facet joints and a disc joint.
- The lumbar vertebrae are the larger than the cervical and thoracic vertebrae because the spine is a weight-bearing structure and more weight is borne through the spine as we go lower in the body.
- L5 articulates inferiorly with the sacrum at the lumbosacral (L5-S1) joint.