L1

The first lumbar vertebra (L1) is the first vertebra of the lumbar region, located between the last thoracic vertebra (T18 or T13 depending on the species) and the second lumbar vertebra (L2).

In vertebrates, lumbar vertebrae form the region of the vertebral column located caudal to the thorax and do not articulate with ribs. They provide support for the trunk and transmit forces toward the pelvis.