Lumbar Vertebra Posterior
As with other vertebrae, each lumbar vertebrae consists of a vertebral body and a vertebral arch. The vertebral arch, consisting of a pair of pedicles and a pair of laminae, enclosing the vertebral foramen (opening) and supports seven processes.
L1 - L5 absence of a foramen transversarium (an opening in the transverse process found only in cervical vertebrae)
L1 - L5 absence of the facets on the side of the body.
The foramen transversarium (found only in the cervical vertebrae) allows for the passage of the vertebral artery and the vertebral vein and the sympathetic nerve plexus. Some people have only 4 lumbar vertebrae and can have up to 6.