Answer
The three divisions of the bony labyrinth are the semicircular canals, the vestibule, and the cochlea.
Work Step by Step
The bony labyrinth of the inner ear is a series of cavities in the temporal bone. These are divisible into three structures; the semicircular canals, the vestibule, and the cochlea.
The vestibule is an ovoid cavity in the bony labyrinth; it contains two membranous sacs ( utricle and saccule), suspended in perilymph ; through their receptors they detect changes in gravitational pull, and changes in head positions.
The bony semi-circular canals are arranged at right angles to one another. There is an anterior, a posterior, and a lateral semicircular canal in each ear. The anterior and posterior canals are vertical; the lateral canal is horizontal. Changes in position of the head perturb the crista ampullaris
in the semicircular duct of the semicircular canal; these receptors alert the brain regarding changes in movements (angular rotation) of the head.
The cochlea is a spiral bony chamber. It extends from the vestibule, then makes about two and a half coils around a bony pillar. A worm-shaped cochlear duct runs through the cochlea; this duct houses the Organ of Corti (spiral organ) which tranduces sound waves into nerve impulses (action potentials}
