What additional bones connect the lumbar vertebrae and form the tailbone?

The lumbar vertebrae are situated in the lower back region and are associated with the sacral and coccygeal regions of the vertebral column. The sacral bones consist of five fused vertebrae that form the sacrum, which connects the lumbar vertebrae to the pelvis. Below the sacrum, the coccygeal region, or coccyx, is composed of several fused vertebrae that create what is commonly known as the tailbone.

Both the sacral and coccygeal bones play crucial roles in providing structural support and stability to the pelvis. The sacrum serves as a foundation for the lumbar spine and connects with the ilium of the pelvis. The coccyx is the terminal segment of the vertebral column and serves as an attachment site for ligaments and muscles, contributing to pelvic floor stability.

Thus, both the sacral and coccygeal bones are vital in creating the connection between the lumbar vertebrae and the overall structure of the lower spine and pelvis, making this answer the most accurate.