Bony labyrinth

The bony labyrinth (or osseous labyrinth, otic capsule, latin: labyrinthus osseus) is a bony capsule that consists of a system of interconnected cavities and canals in the internal ear that enclose the membranous labyrinth. The bony labyrinth is composed three parts:

  • vestibule,
  • semicircular canals (3),
  • cochlea.

Within the bony labyrinth lies the membranous labyrinth that consists of small sacs and tubules which contain receptors for hearing, movement of the head and position of the head.

The vestibule is the central part of the bony labyrinth that encloses the membranous sacs - saccule and utricle.

The semicircular canals are three bony canals situated behind the vestibule and arranged in three mutually perpendicular planes. The semicircular canals of the bony labyrinth contain perilymphatic fluid and enclose the membranous semicircular ducts.

The cochlea is a bony canal that forms a spiral making 2.5 turns and lies in front and medially of the vestibule. The cochlea of the bony labyrinth encloses the membranous cochlear duct.