The semicircular canals and the vestibule of the bony labyrinth of the temporal bone, the utriculus
, saccule, and semicircular ducts of the membranous labyrinth of the inner ear, and the vestibular division of cranial nerve VIII are responsible for balance and equilibrium.
The labyrinth includes three semicircular canals and three compartments: saculus, utriculus
and lagena; each sac contains one otolith, the lapillus, the sagitta and the asteriscus, respectively (Morales-Nin 2000, Berra & Aday 2004, Popper et al.
These canals form chambers containing otoliths, the lapillus is included in the utriculus
(figure 1), the sagitta in the sacculus and the asteriscus is included in the lagena (figure 2).
The vestibular apparatus can be divided into three semi-circular canals and the otolith organ, which is composed of the utriculus
The labyrinth is a complex structure which, amongst other components, houses three earstones or otoliths which lie in three confluent compartments, the utriculus
, the sacculus and the lagena.