Posterior cricoarytenoid muscle

The posterior cricoarytenoid muscles are small, paired intrinsic muscles of the larynx that extend between cricoid cartilage to the arytenoid cartilages in the larynx.

Posterior cricoarytenoid
Muscles of larynx. Side view. Right lamina of thyroid cartilage removed.
Details
Originposterior part of the cricoid
Insertionposterior surface of muscular process of the arytenoid cartilage
Nerverecurrent laryngeal nerve branch of the vagus nerve (CN X)
Actionsabducts and laterally rotates arytenoid cartilage, pulling vocal ligaments away from the midline and forward and so opening rima glottidis
Antagonistlateral cricoarytenoid muscle
Identifiers
LatinMusculus cricoarytaenoideus posterior
TA98A06.2.08.004
TA22196
FMA46576
Anatomical terms of muscle

Structure

Origin and insertion

The posterior cricoarytenoid originates from the posterior surface of the posterior quadrate lamina of the cricoid cartilage. It inserts onto the muscular process of the arytenoid cartilage.[1] Its distinct medial and lateral bellies insert onto opposite surfaces of the muscular process.[1]

Nerve supply

The posterior cricoarytenoid muscles are supplied by the anterior division of the recurrent laryngeal nerve, a branch of the vagus nerve (CN X).[2][3] Sometimes, different parts of the muscle (such as the medial and lateral muscle bellies) are supplied by separate branches.[2] This may vary between 1 and 6 branches, usually 2 or 3.[3] These may connect within the muscle.[3]

Function

The posterior cricoarytenoid muscles are the only muscles to open the vocal cords.[4] By rotating the arytenoid cartilages laterally, these muscles abduct the vocal cords.[4][5] This opens the rima glottidis.[5] : 9  This is important in breathing and speech.[4] Their action opposes the lateral cricoarytenoid muscles.

Clinical significance

Paralysis of the posterior cricoarytenoid muscles may lead to asphyxia, as they are the only laryngeal muscles to open the vocal cords (allowing breathing).[6] Denervation leads to a slow fibrosis that worsens over many months.[7]

Additional images
  • The cartilages of the larynx. Posterior view.
  • Muscles of larynx. Posterior view.
  • Muscles of the larynx, seen from above.
  • Dissection of the muscles of the palate from behind.
  • Posterior cricoarytenoid muscle
  • Posterior cricoarytenoid muscle
  • Posterior cricoarytenoid muscle

See also
Wikimedia Commons has media related to Posterior cricoarytenoid muscle.
This article uses anatomical terminology.

References
  1. Bryant, Nancy Jones; Woodson, Gayle E.; Kaufman, Kenton; Rosen, Clark; Hengesteg, Arne; Chen, Naidy; Yeung, Daniel (1996-12-01). "Human Posterior Cricoarytenoid Muscle Compartments: Anatomy and Mechanics". Archives of Otolaryngology–Head & Neck Surgery. 122 (12): 1331–1336. doi:10.1001/archotol.1996.01890240039009. ISSN 0886-4470.
  2. Sanders, Ira; Wu, Bei-Lian; Mu, Liancai; Biller, Hugh P. (1994). "The innervation of the human posterior cricoarytenoid muscle: Evidence for at least two neuromuscular compartments". The Laryngoscope. 104 (7): 880–884. doi:10.1288/00005537-199407000-00019. ISSN 1531-4995.
  3. Maranillo, Eva; León, Xavier; Ibañez, Marta; Orús, César; Quer, Miguel; Sañudo, José Ramón (2003). "Variability of the Nerve Supply Patterns of the Human Posterior Cricoarytenoid Muscle". The Laryngoscope. 113 (4): 602–606. doi:10.1097/00005537-200304000-00004. ISSN 1531-4995.
  4. Brancatisano, T. P.; Dodd, D. S.; Engel, L. A. (1 October 1984). "Respiratory activity of posterior cricoarytenoid muscle and vocal cords in humans". Journal of Applied Physiology. 57 (4): 1143–1149. doi:10.1152/jappl.1984.57.4.1143. ISSN 8750-7587.
  5. Hydman, Jonas (2008). Recurrent laryngeal nerve injury. Stockholm. ISBN 978-91-7409-123-6.
  6. The Arytenoid Cartilages - a clinical overview. 2002, Dr. C Kay et al. Thorne Publishing (C)
  7. Zealear, David L.; Hamdan, Abdul-Latif; Ratney, Cheryl L. (1994-10-01). "Effects of Denervation on Posterior Cricoarytenoid Muscle Physiology and Histochemistry". Annals of Otology, Rhinology & Laryngology. 103 (10): 780–788. doi:10.1177/000348949410301007. ISSN 0003-4894.
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