The<unk>  (Latin:<unk> us<unk> itarius) is a compact fiber bundle that extends longitudinally through the posterolateral region of the medulla.  The<unk>  is surrounded by the nucleus of the<unk> , and descends to the upper cervical segments of the spinal cord.
Solitary tract
Danger space
Ganglion
Duct 
Operon
Reposal
Lateral horn
Growth cone