Medically reviewed by Jennifer Steinhoff, MD Key Takeaways The lumbar spine includes five vertebrae that help with mobility ...

The spine (aka backbone) is a linked column of bones running from the head down to the lower back. Bone segments form the column. One bone segment is a vertebra, and multiple bone segments are ...

For decades, scientists believed that a spine with multiple segments was an exclusive feature of land-dwelling animals. But the discovery of the same anatomical feature in a 345-million-year-old eel ...