anatomical structure cauda equina UMLS:C0007458 FMA:52590 SCTID:263377004 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. EMAPA:37468 MESH:D002420 MA:0003045 UBERON:0012337 Wikipedia:Cauda_equina NCIT:C12689 filum terminale neuronames:1626