Posterior cricoarytenoid muscle

Posterior cricoarytenoid
Muscles of larynx. Side view. Right lamina of thyroid cartilage removed.
Latin	musculus cricoarytenoideus posterior
Gray's	subject #236 1082
Origin	posterior part of the cricoid
Insertion	muscular process of the arytenoid cartilage
Artery	{{{Blood}}}
Nerve	recurrent laryngeal branch of the vagus
Actions	abducts and laterally rotates the cartilage, pulling the vocal ligaments away from the midline and forward and so opening the rima glottidis
Antagonist	Lateral cricoarytenoid muscle

The posterior cricoarytenoid muscles are extremely small, paired muscles that extend from the posterior cricoid cartilage to the arytenoid cartilages in the larynx. By rotating the arytenoid cartilages laterally, these muscles abduct the vocal cords and thereby open the rima glottidis. Their action opposes the lateral cricoarytenoid muscles. The posterior cricoarytenoid muscles receive innervation from the recurrent laryngeal branch of the vagus nerve (CN X).

Paralysis of the posterior cricoarytenoid muscles may lead to asphyxiation as they are the only laryngeal muscles to open the true vocal folds, allowing inspiration and expiration.^[1]

Additional images

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  The cartilages of the larynx. Posterior view.

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  Muscles of larynx. Posterior view.

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  Muscles of the larynx, seen from above.

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  Dissection of the muscles of the palate from behind.

References

1. ^ The Arytenoid Cartilages - a clinical overview. 2002, Dr. C Kay et al. Thorne Publishing (C)

External links

• LUC pcay
• Atlas of anatomy at UMich rsa4p2
• posterior+cricoarytenoid+muscle at eMedicine Dictionary
• lesson11 at The Anatomy Lesson by Wesley Norman (Georgetown University) (larynxmuscles)