Semicircular canals
Last revised by Bahman Rasuli ◉ on 10 Dec 2020
Citation, DOI & article data
Citation:
Basim D, Rasuli B, Bell D, et al. Semicircular canals. Reference article, Radiopaedia.org (Accessed on 01 Feb 2023) https://doi.org/10.53347/rID-42094
Permalink:
rID:
42094
Article created:
06 Jan 2016 by Dr Ali Basim
Revisions:
19 times by 8 users - see full revision history
Systems:
Sections:
Synonyms:
- Semicircular canal (SCC)
- Semicircular canal
The three semicircular canals (SCCs) are components of the bony labyrinth within the petrous temporal bone, along with the cochlea and vestibule. They contain the semicircular ducts, part of the membranous labyrinth which are responsible for kinetic balance.
Gross anatomy
There are three semicircular canals on each side, the superior, posterior and lateral canals, each forming two-thirds of a full circle, which are oriented perpendicular (at right angles) to each other.
The lateral semicircular canal opens directly into the vestibule, whilst the superior and posterior semicircular canals form a common crus before entering the vestibule. They have differing and variable lengths but uniform diameters of ~1 mm.
Superior (anterior) semicircular canal (SSCC)
- oriented in the vertical plane perpendicular (transverse) to the long axis of the petrous temporal bone
- it lies under the arcuate eminence on the anterior surface of the petrous temporal bone
- hair cells of the superior semicircular duct supplied by the superior division of the vestibulocochlear nerve (CN VIII)
Posterior semicircular canal (PSCC)
- oriented in the vertical plane parallel to the long axis of the petrous temporal bone
- hair cells of the posterior semicircular duct supplied by the inferior division of CN VIII
Lateral (horizontal) semicircular canal (LSCC)
- oriented 30° to the horizontal
- shortest of the semicircular canals
- hair cells of the lateral semicircular duct supplied by the superior division of CN VIII
Related pathology
References
- 1. Last's Anatomy. Churchill Livingstone. (2011) ISBN:0702033952. Read it at Google Books - Find it at Amazon
- 2. Joshi VM, Navlekar SK, Kishore GR et-al. CT and MR imaging of the inner ear and brain in children with congenital sensorineural hearing loss. Radiographics. 2012;32 (3): 683-98. doi:10.1148/rg.323115073 - Pubmed citation
- 3. Susan Standring. Gray's Anatomy. ISBN: 9780702052309
- 4. Butler P, Mitchell A, Healy JC. Applied Radiological Anatomy. Cambridge University Press. (2012) ISBN:0521766664. Read it at Google Books - Find it at Amazon
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