The stapes or stirrup is the stirrup-shaped small bone or ossicle in the middle ear which is attached to the incus laterally and to the fenestra ovalis, the 'oval window' medially. The oval window is adjacent to the vestibule of the inner ear. The stapes is the smallest and lightest bone in the human body. The stapes transmits the sound vibrations from the incus to the membrane of the inner ear inside the fenestra ovalis. The stapes is also stabilized by the stapedius muscle, which is innervated by the facial nerve. In non-mammalian vertebrates, the bone homologous to the stapes is usually called the columella; however, in reptiles, either term may be used[WP,unvetted]. [ ]

Synonyms: stirrup

This is just here as a test because I lose it

Term information


uberon_slim, pheno_slim

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development notes

As the stapes first develops embryologically from the 6th to 8th week of life, it surrounds the stapedial artery, which supplies the majority of the vasculature of the embryonic head. After that period, the external carotid artery is generated and takes over for the stapedial artery, which subsequently involutes, leaving the stapes with a windowframe-like structure[WP] The stapes develops at the cranial end of the second branchial arch through an independent anlage of the cartilage of this arch. Between the stapedial anlage and the cranial end of the Reichert's cartilage there is a formation called the interhyale, the internal segment of which gives rise to the tendon of the stapedial muscle. The stapedial anlage is a unique formation with two distinct parts: the superior part that will comprise the base and the inferior part that will be crossed by the stapedial artery during embryonic development and will constitute the limbs and the head of the stapes. According to the results, the otic capsule is not involved in formation of the base of the stapes.

has related synonym

os intermedium




stilus columellare



columella auris


os columellare



homology notes

This structure (the hyomandibular), on ontogenic grounds alone, can be considered homologous with the amphibian and reptilian columella and the mammalian stapes.[well established][VHOG]



taxon notes

'This structure [the hyomandibular], on ontogenic grounds alone, can be considered homologous with the amphibian and reptilian columella and the mammalian stapes.' Gerrie J, The phylogeny of the mammalian tympanic cavity and auditory ossicles. The Journal of Laryngology and Otology (1948) 62:339-357?[VHOG].