Which structure is referred to as the tailbone?

The structure known as the tailbone is the coccyx. This small, triangular bone is located at the base of the vertebral column and is comprised of several fused vertebrae. It serves as an attachment point for various muscles, tendons, and ligaments, contributing to pelvic stability and posture. The coccyx plays a role in supporting the weight of the body when sitting, especially when leaning back.

The sacrum, while located above the coccyx, is a larger bony structure formed from five fused vertebrae and is a key component of the pelvis, forming joints with the hip bones. The thoracic spine refers to the twelve vertebrae located in the upper and mid-back region, which are distinct from those associated with the tailbone. Similarly, the lumbar vertebrae consist of five vertebrae in the lower back and participate in supporting the weight of the upper body, but they are not related to the tailbone itself. The coccyx’s unique structure and location make it the definitive answer to the question regarding the tailbone.