• (vestibule, labyrinth) An oval, bony chamber of the inner ear, part of the bony labyrinth. It is continuous with bony COCHLEA anteriorly, and SEMICIRCULAR CANALS posteriorly. The vestibule contains two communicating sacs (utricle and saccule) of the balancing apparatus. The oval window on its lateral wall is occupied by the base of the STAPES of the MIDDLE EAR.
  NLM Medical Subject Headings
  U.S. National Library of Medicine, 2025
• Region of membranous labyrinth of internal ear, each intance of which includes some utricle and saccule lodged within some vestibule and some semicircular ducts lodged eccentrically in some corresponding canals.
  Foundational Model of Anatomy
  University of Washington, 2017
• (vestibular apparatus) Structures of the inner ear concerned with reception and transduction of stimuli of equilibrium; they include the semicircular canals, the utricle, and the saccule.
  CRISP Thesaurus
  National Institutes of Health, 2006
• (vestibule of the ear) The central cavity of the osseous labyrinth.
  NCI
  U.S. National Cancer Institute, 2021
• The innermost part of the ear in vertebrates, which primarily functions as sound detection and balance.
  NCI
  U.S. National Cancer Institute, 2021