NCIt definition : The collection of spinal nerve roots, arising from lumbar pairs two through five,
sacral pairs one through five, and the coccygeal nerve, that branch off the conus
medullaris at the termination of the spinal cord, and float freely within the lumbar
cistern before exiting the spinal column at the appropriate vertebra.;
Alternative definition : UBERON: The cauda equina is a structure within the lower end of the spinal column
of most vertebrates, that consists of nerve roots and rootlets from above. The space
in which the cerebrospinal fluid is present is actually an extension of the subarachnoid
space.;