There are 5 lumbar vertebrae in the lumbar region. There are 5 sacral vertebrae, which are fused as one bone and known as the sacrum, in the sacral region. There are 3 to 5 coccygeal vertebrae, which ...

The sacrum and the coccyx each consist of multiple bones that fuse over time. L5-S1 consists of the last bone in the lumbar ...