Editing Vestibular system (section)

===Structure===
{{Main|Semicircular canal}}

Since the world is three-dimensional, the vestibular system contains three [[semicircular canals]] in each [[Labyrinth (inner ear)|labyrinth]]. They are approximately [[orthogonal]] (at right angles) to each other, and are the ''[[Horizontal semicircular canal|horizontal]]'' (or ''lateral''), the ''[[anterior semicircular canal]]'' (or ''superior''), and the ''[[posterior semicircular canal|posterior]]'' (or ''inferior'')  semicircular canal. Anterior and posterior canals may collectively be called ''vertical semicircular canals''.
# Movement of fluid within the '''horizontal''' semicircular canal corresponds to rotation of the head around a vertical axis (i.e. the neck), as when doing a [[pirouette]].
# The '''anterior''' and '''posterior''' semicircular canals detect rotations of the head in the [[sagittal plane]] (as when nodding), and in the [[coronal plane|frontal plane]], as when [[cartwheeling]]. Both anterior and posterior canals are oriented at approximately 45° between frontal and sagittal planes.
The movement of fluid pushes on a structure called the [[Ampullary cupula|cupula]] which contains hair cells that transduce the mechanical movement to electrical signals.<ref name="Boron 2005">{{cite book |author=[[Emile Boulpaep|Boulpaep, Emile L.]]; [[Walter Boron|Boron, Walter F.]] |title=Medical physiology: a cellular and molecular approach |publisher=Elsevier Saunders |location=St. Louis, Mo |year=2005 |isbn=978-1-4160-2328-9 |oclc=56963726 }}</ref>