Conus medullaris

The conus medullaris (Latin for "medullary cone") is the tapered, lower end of the spinal cord. It occurs near lumbar vertebral levels 1 (L1) and 2 (L2), occasionally lower. The upper end of the conus medullaris is usually not well defined.

After the spinal cord tapers out, the spinal nerves continue to branch out diagonally, forming the cauda equina.