Posterior cricoarytenoid muscle

Posterior cricoarytenoid
Muscles of larynx. Side view. Right lamina of thyroid cartilage removed.
Details
Origin	posterior part of the cricoid
Insertion	muscular process of the arytenoid cartilage
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
Identifiers
Latin	Musculus cricoarytaenoideus posterior
Dorlands /Elsevier	m_22/12548696
TA	A06.2.08.004
FMA	46576
*Anatomical terms of muscle* [edit on Wikidata]

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

Structure

Innervation

The posterior cricoarytenoid muscles receive innervation from the recurrent laryngeal branch of the vagus nerve.^[1] ^:10

Function

The cricoarytenoid muscles are the only muscles to open the vocal cords. By rotating the arytenoid cartilages laterally, these muscles abduct the vocal cords and thereby open the rima glottidis.^[1] ^:9 Their action opposes the lateral cricoarytenoid muscles.

Clinical significance

Paralysis of the posterior cricoarytenoid muscles may lead to asphyxiation as they are the only laryngeal muscles to open the true vocal cords, allowing inspiration and expiration.^[2]

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

References

1 2 Hydman, Jonas (2008). Recurrent laryngeal nerve injury. Stockholm. ISBN 978-91-7409-123-6.
↑ The Arytenoid Cartilages - a clinical overview. 2002, Dr. C Kay et al. Thorne Publishing (C)

External links

Atlas image: rsa4p2 at the University of Michigan Health System
lesson11 at The Anatomy Lesson by Wesley Norman (Georgetown University) (larynxmuscles)

Muscles of the neck

Cervical	Platysma Sternocleidomastoid Longus capitis Longus colli Scalene anterior middle posterior Rectus capitis anterior muscle Rectus capitis lateralis muscle

Suboccipital	Rectus capitis posterior major minor Obliquus capitis inferior superior

Suprahyoid	Mylohyoid Stylohyoid Digastric Geniohyoid

Infrahyoid	Thyrohyoid Sternohyoid Sternothyroid Omohyoid

Pharynx	Pharyngeal constrictor superior middle inferior Stylopharyngeus Salpingopharyngeus

Larynx	Cricothyroid Cricoarytenoid posterior lateral Arytenoid oblique arytenoid aryepiglottic transverse arytenoid Thyroarytenoid vocal thyroepiglottic

Trachea	Trachealis

Fasciae	Deep cervical fascia Pretracheal fascia Prevertebral fascia Investing layer Carotid sheath Alar fascia Palatine aponeurosis Buccopharyngeal fascia Pharyngobasilar fascia Pharyngeal raphe

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