Final answer:
The left lumbar region is typically referred to as Region 2, situated inferior to the umbilical region with the lumbar vertebrae numbered L1-L5 located in this area.
Step-by-step explanation:
The region number for the left lumbar region, when describing the nine regions of the abdomen, is typically referred to as Region 2. This lumbar area exists on both the left and right sides of the abdominal cavity and is situated inferior to the umbilical region and lateral to the spinal column, where the five lumbar vertebrae (numbered L1-L5) are located.
When putting the vertebral regions in order from the closest to the head to the farthest, the correct sequence is: cervical, thoracic, lumbar, sacral, and coccygeal. Each of these regions contains a different number of vertebrae with the thoracic vertebrae totaling twelve (T1-T12) and the lumbar vertebrae totaling five (L1-L5).