Expected headings
"Internal vertebral venous plexus"
"External vertebral venous plexus"
"Basivertebral veins"
"The external vertebral venous plexuses are composed of the anterior and posterior external vertebral plexuses that surround the vertebral column. In addition to the internal vertebral venous plexus, they form several connections with the azygos, lumbar and deep cervical veins."