Posterior cricoarytenoid muscle

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Posterior cricoarytenoid
Musculuscricoarytenoideusposterior.png
Muscles of larynx. Side view. Right lamina of thyroid cartilage removed.
Details
Origin Posterior part of the cricoid
Insertion Posterior surface of muscular process of the arytenoid cartilage
Nerve Recurrent laryngeal nerve branch of the vagus nerve (CN X)
Actions Abducts and laterally rotates arytenoid cartilage, pulling vocal ligaments away from the midline and forward and so opening rima glottidis
Antagonist Lateral cricoarytenoid muscle
Identifiers
Latin musculus cricoarytaenoideus posterior
TA98 A06.2.08.004
TA2 2196
FMA 46576
Anatomical terms of muscle

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.

Contents

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; [1] the distinct orientations of muscle fibres may indicate that the muscle could produce different movements depending upon which portion of the muscle contracts. [2]

According to a cadaveric study, the muscle exhibits two distinct bellies - a medial belly and a lateral belly - which differ in the orientation of their muscle fibres and the site of insertion at the muscular process. [3]

Origin

The muscle originates from (the posterior aspect of) the lamina of cricoid cartilage. [1]

Insertion

The muscle's fibres converge to insert onto (the superior, posterior and (minimally the) anterolateral aspects of) the muscular process of the ipsilateral arytenoid cartilage [4] (its medial belly and lateral belly insert onto the muscular process medially and laterally, respectively). [3]

Innervation

The posterior cricoarytenoid muscle receives motor innervation from (the anterior division of) the recurrent laryngeal nerve (itself a branch of the vagus nerve (CN X)). [2] [5]

Different parts of the muscle (such as the medial and lateral muscle bellies) are often innervated by separate branches. [2] There may be 1-6 branches, but are usually 2-3. These may connect within the muscle. [5] This innervation modality may indicate that the different parts of the muscle can be activated at different times so that it can produce different movements. [2]

Vasculature

The muscle receives arterial supply from the laryngeal branches of the superior thyroid artery and inferior thyroid artery. [1]

Actions/movements

The muscle rotates the arytenoid cartilages laterally, thereby abducting the vocal processes and the vocal folds that are attached to them. In this, the muscle is an antagonist of the lateral cricoarytenoid muscle. [1]

The muscle additionally draws the arytenoid cartilages posterior-ward, thus (assisting in) lengthening the vocal cords (here acting as synergist of the cricothyroid muscle). The lateral-most portion of the muscle also draws the arytenoid cartilages lateral-ward, making the rima glottidis into a triangular shape. [1]

Function

The posterior cricoarytenoid muscles are the only muscles to open the vocal cords. [1] [6] By abducting the vocal folds, the muscle opens the rima glottidis. [7] :9 This is important in breathing and speech. [6] The muscles participate in the production of unvoiced vocal sounds. [1]

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). [8] Denervation leads to a slow fibrosis that worsens over many months. [9]

Additional images

See also

Related Research Articles

The term phonation has slightly different meanings depending on the subfield of phonetics. Among some phoneticians, phonation is the process by which the vocal folds produce certain sounds through quasi-periodic vibration. This is the definition used among those who study laryngeal anatomy and physiology and speech production in general. Phoneticians in other subfields, such as linguistic phonetics, call this process voicing, and use the term phonation to refer to any oscillatory state of any part of the larynx that modifies the airstream, of which voicing is just one example. Voiceless and supra-glottal phonations are included under this definition.

<span class="mw-page-title-main">Larynx</span> Voice box, an organ in the neck of amphibians, reptiles, and mammals

The larynx, commonly called the voice box, is an organ in the top of the neck involved in breathing, producing sound and protecting the trachea against food aspiration. The opening of larynx into pharynx known as the laryngeal inlet is about 4–5 centimeters in diameter. The larynx houses the vocal cords, and manipulates pitch and volume, which is essential for phonation. It is situated just below where the tract of the pharynx splits into the trachea and the esophagus. The word 'larynx' comes from the Ancient Greek word lárunx ʻlarynx, gullet, throat.ʼ

<span class="mw-page-title-main">Recurrent laryngeal nerve</span> Nerve in the human body

The recurrent laryngeal nerve (RLN) is a branch of the vagus nerve that supplies all the intrinsic muscles of the larynx, with the exception of the cricothyroid muscles. There are two recurrent laryngeal nerves, right and left. The right and left nerves are not symmetrical, with the left nerve looping under the aortic arch, and the right nerve looping under the right subclavian artery then traveling upwards. They both travel alongside the trachea. Additionally, the nerves are among the few nerves that follow a recurrent course, moving in the opposite direction to the nerve they branch from, a fact from which they gain their name.

<span class="mw-page-title-main">Rima glottidis</span> Opening between the true vocal cords and the arytenoid cartilages of the larynx

The rima glottidis is the opening between the two true vocal cords anteriorly, and the two arytenoid cartilages posteriorly. It is part of the larynx.

<span class="mw-page-title-main">Lateral cricoarytenoid muscle</span>

The lateral cricoarytenoid is an intrinsic muscle of the larynx. It attaches at the cricoid cartilage anteriorly, and at the arytenoid cartilage of the same side posteriorly. It is innervated by the recurrent laryngeal nerve. It acts to close the rima glottidis, thus closing the airway.

<span class="mw-page-title-main">Cricoid cartilage</span> Complete ring of cartilage around the trachea

The cricoid cartilage, or simply cricoid or cricoid ring, is the only complete ring of cartilage around the trachea. It forms the back part of the voice box and functions as an attachment site for muscles, cartilages, and ligaments involved in opening and closing the airway and in producing speech.

<span class="mw-page-title-main">Cricothyroid muscle</span> Muscle of the larynx

The cricothyroid muscle is the only tensor muscle of the larynx aiding with phonation. It is innervated by the superior laryngeal nerve. Its action tilts the thyroid forward to help tense the vocal cords, thus increasing the pitch of the voice.

<span class="mw-page-title-main">Arytenoid cartilage</span> Part of the larynx, to which the vocal folds (vocal cords) are attached

The arytenoid cartilages are a pair of small three-sided pyramids which form part of the larynx. They are the site of attachment of the vocal cords. Each is pyramidal or ladle-shaped and has three surfaces, a base, and an apex. The arytenoid cartilages allow for movement of the vocal cords by articulating with the cricoid cartilage. They may be affected by arthritis, dislocations, or sclerosis.

<span class="mw-page-title-main">Inferior pharyngeal constrictor muscle</span> Skeletal muscle of the pharynx

The inferior pharyngeal constrictor muscle is a skeletal muscle of the neck. It is the thickest of the three outer pharyngeal muscles. It arises from the sides of the cricoid cartilage and the thyroid cartilage. It is supplied by the vagus nerve. It is active during swallowing, and partially during breathing and speech. It may be affected by Zenker's diverticulum.

<span class="mw-page-title-main">Arytenoid muscle</span> Muscle of the larynx

The arytenoid muscle or interarytenoid muscle is a composite intrinsic muscle of the larynx, consisting of a transverse part and an oblique part - the two parts may be considered as separate muscles: an unpaired transverse arytenoid muscle, and a bilaterally paired oblique arytenoid muscle.

<span class="mw-page-title-main">Aryepiglottic muscle</span>

The aryepiglottic muscle or aryepiglotticus muscle is an intrinsic muscle of the larynx.

<span class="mw-page-title-main">Oblique arytenoid</span>

The oblique arytenoid is bilaterally paired intrinsic muscle of the larynx. It is superficial to the transverse arytenoid; the oblique and transverse arytenoids are often considered two parts of a single muscle - the interarytenoid muscle.

<span class="mw-page-title-main">Superior laryngeal nerve</span> Branch of the vagus nerve

The superior laryngeal nerve is a branch of the vagus nerve. It arises from the middle of the inferior ganglion of vagus nerve and additionally also receives a sympathetic branch from the superior cervical ganglion.

<span class="mw-page-title-main">Aryepiglottic fold</span> Folds near the larynx

The aryepiglottic folds are triangular folds of mucous membrane of the larynx. They enclose ligamentous and muscular fibres. They extend from the lateral borders of the epiglottis to the arytenoid cartilages, hence the name 'aryepiglottic'. They contain the aryepiglottic muscles and form the upper borders of the quadrangular membrane. They have a role in growling as a form of phonation. They may be narrowed and cause stridor, or be shortened and cause laryngomalacia.

<span class="mw-page-title-main">Transverse arytenoid</span> Muscle in the larynx

The transverse arytenoid is an unpaired intrinsic muscle of the larynx. It is situated deep to the two oblique arytenoids; the oblique and transverse arytenoids are often considered two parts of a single muscle - the interarytenoid (arytenoid) muscle.

<span class="mw-page-title-main">Cricoarytenoid joint</span> Joint connecting the cricoid cartilage and the arytenoid cartilage

The cricoarytenoid joint is a joint connecting the cricoid cartilage and the arytenoid cartilage. It is a very shallow ball-and-socket joint. It allows for rotation and gliding motion. This controls the abduction and adduction of the vocal cords.

<span class="mw-page-title-main">Vocal process</span>

In the human larynx, the vocal process is the anterior angle of the base of the arytenoid cartilage, as it projects horizontally forward and gives attachment to the vocal ligament.

Endoscopic laser cordectomy, also known as Kashima operation, is an endoscopic laser surgical procedure performed for treating the respiratory difficulty caused as a result of bilateral abductor vocal fold paralysis. Bilateral vocal fold paralysis is basically a result of abnormal nerve input to the laryngeal muscles, resulting in weak or total loss of movement of the laryngeal muscles. Most commonly associated nerve is the vagus nerve or in some cases its distal branch, the recurrent laryngeal nerve. Paralysis of the vocal fold may also result from mechanical breakdown of the cricoarytenoid joint. It was first described in by Kashima in 1989.

Thyroplasty is a phonosurgical technique designed to improve the voice by altering the thyroid cartilage of the larynx, which houses the vocal cords in order to change the position or the length of the vocal cords.

Arytenoid adduction is a surgical procedure used to treat vocal cord paralysis. A suture is used to emulate the action of the lateral cricoarytenoid muscle and position the paralyzed vocal cord closer to the midline. This allows the two vocal cords to meet and can improve speaking and swallowing ability for affected patients. Arytenoid adduction is often performed in conjunction with medialization thyroplasty.

References

  1. 1 2 3 4 5 6 7 Standring, Susan (2020). Gray's Anatomy: The Anatomical Basis of Clinical Practice (42nd ed.). New York. p. 727. ISBN   978-0-7020-7707-4. OCLC   1201341621.{{cite book}}: CS1 maint: location missing publisher (link)
  2. 1 2 3 4 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. PMID   8022253. S2CID   45469959.
  3. 1 2 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. PMID   8956745.
  4. Standring, Susan (2020). Gray's Anatomy: The Anatomical Basis of Clinical Practice (42th ed.). New York. p. 727. ISBN   978-0-7020-7707-4. OCLC   1201341621.{{cite book}}: CS1 maint: location missing publisher (link)
  5. 1 2 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. PMID   12671414. S2CID   23686151.
  6. 1 2 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. PMID   6501030.
  7. Hydman, Jonas (2008). Recurrent laryngeal nerve injury. Stockholm. ISBN   978-91-7409-123-6.{{cite book}}: CS1 maint: location missing publisher (link)
  8. The Arytenoid Cartilages - a clinical overview. 2002, Dr. C Kay et al. Thorne Publishing (C)
  9. 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. PMID   7944169. S2CID   22946351.