Why do the bones of the spine get bigger the further down it goes?

The bones of the spine, or vertebrae, increase in size from the cervical region (neck) to the lumbar region (lower back) to support the greater weight and stress experienced by the lower spine. As the body moves downward, the vertebrae must bear more load from the upper body, requiring larger and stronger bones for stability and support. This design helps maintain proper posture and balance while allowing for flexibility and movement.