Corpus: Posterior cricoarytenoid muscle: Unterschied zwischen den Versionen

The posterior cricoarytaenoid muscle is part of the laryngeal musculature. It is the only opener of the glottis and is also referred to as the "posticus" in clinical jargon.

The posterior cricoarytaenoid muscle is located dorsally on the larynx between the cartilago cricoidea and cartilago arytaenoidea (cartilage). It originates on the posterior surface of the cricoid cartilage plate (lamina cartilaginis cricoideae) and extends laterally upwards to the processus muscularis of the cartilage.

During contraction, it swivels the cartilage outwards and rotates it around its vertical axis. This lifts the vocalis process and guides it outwards.

Like all internal laryngeal muscles, the posterior cricoarytaenoid muscle is innervated by the inferior laryngeal nerve from the recurrent laryngeal nerve.

The posterior cricoarytaenoid muscle is the only laryngeal muscle that acts as a glottis opener. It therefore ensures the so-called breathing position of the glottis with every inspiration. At the same time, together with the cricothyroid muscle, it causes the vocal cords to tense. During sleep, its tone ensures that the glottis remains open.

The lateral cricoarytenoid muscle and the other three glottis closers have an antagonistic effect.

The unilateral loss of the posterior cricoarytenoid muscle (posticus paralysis) (e.g. due to recurrent paresis) leads to hoarseness.

In the case of bilateral failure, the glottis is closed so that the airways are blocked. This results in acute dyspnoea and inspiratory stridor, so that a tracheostomy may be necessary in an emergency.