<P> In the vestibular system, equilibrioception is determined by the level of a fluid called endolymph in the labyrinth, a complex set of tubing in the inner ear . </P> <P> When the sense of balance is interrupted it causes dizziness, disorientation and nausea . Balance can be upset by Ménière's disease, superior canal dehiscence syndrome, an inner ear infection, by a bad common cold affecting the head or a number of other medical conditions including but not limited to vertigo . It can also be temporarily disturbed by quick or prolonged acceleration, for example riding on a merry - go - round . Blows can also affect equilibrioreception, especially those to the side of the head or directly to the ear . </P> <P> Most astronauts find that their sense of balance is impaired when in orbit because they are in a constant state of weightlessness . This causes a form of motion sickness called space adaptation syndrome . </P> <P> This overview also explains acceleration as its processes are interconnected with balance . </P>

Which is the best description of the vestibular sense