The posterior cricoarytenoid muscle is a (bilaterally paired) intrinsic muscle of the larynx. It arises from the cricoid cartilage; it inserts onto the arytenoid cartilage of the same side. It is innervated by the recurrent laryngeal nerve. Each acts to open the vocal folds by pulling the vocal fold of the same side laterally. It participates in the production of sounds.

Structure

The muscle is directed superiorly and laterally from its origin to its insertion. The muscle's fibres vary in orientation superoinferiorly: the superior-most fibres are nearly horizontally oriented, the intermediate fibres are obliquely oriented, and the inferior-most fibres are nearly vertically oriented; the distinct orientations of muscle fibres may indicate that the muscle could produce different movements depending upon which portion of the muscle contracts.

Origin

The muscle originates from (the posterior aspect of) the lamina of cricoid cartilage. (its medial belly and lateral belly insert onto the muscular process medially and laterally, respectively).

Different parts of the muscle (such as the medial and lateral muscle bellies) are often innervated by separate branches. By abducting the vocal folds, the muscle opens the rima glottidis. This is important in breathing and speech. Denervation leads to a slow fibrosis that worsens over many months.

Additional images

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File:Gray950.png|The cartilages of the larynx. Posterior view.

File:Gray958.png|Muscles of larynx. Posterior view.

File:Gray960.png|Muscles of the larynx, seen from above.

File:Gray1028.png|Dissection of the muscles of the palate from behind.

File:Slide6sss.JPG|Posterior cricoarytenoid muscle

File:Slide13sss.JPG|Posterior cricoarytenoid muscle

File:Slide4kkkk.JPG|Posterior cricoarytenoid muscle

</gallery>

See also

  • Recurrent laryngeal nerve

References

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