Is as good as it gets. All vertebrates, from mice to whales, have a set of three mutually perpendicular fluid-filled tubes—the vestibular semicircular canals (SCCs)—housed in each inner ear. The SCCs mechanically sense rotation, a function that is imperative not only for maintaining balance but also for vision: The SCCs’ neural output causes a reflexive, compensating motion of the eyes, which allows a fixed gaze to be maintained even while the head is moving. Knowing how the canals work is also important for understanding various forms of dizziness. Roughly, an SCC is donut-shaped, with a major radius of a few millimeters and minor radius of a few tenths of a millimeter. Each torus is interrupted by a membrane called a cupula that is impregnated with tiny hairs for sensing the sloshing of the fluid through the canal. Those hairs trigger the neural signal. Incredibly, although vertebrates span nearly three orders...
Philip F. Schewe; Our sense of balance. Physics Today 1 January 2005; 58 (1): 9. https://doi.org/10.1063/1.4796739
Download citation file:
Purchase an annual subscription for $25. A subscription grants you access to all of Physics Today's current and backfile content.