|Muscles of larynx. Side view. Right lamina of thyroid cartilage removed.|
|Gray's||subject #236 1081|
|Origin||Anterior and lateral cricoid cartilage|
|Insertion||Inferior cornu and lamina of the thyroid cartilage|
|Nerve:||external laryngeal branch of the vagus|
|Action:||tension and elongation of the vocal folds|
The cricothyroid muscle attaches to the anterolateral aspect of the cricoid and the inferior cornu and lower lamina of the thyroid cartilage, tilting the thyroid forwards and tensing the vocal cords. It is the only laryngeal muscle supplied by the external laryngeal nerve (rather than the recurrent laryngeal nerve).
The Cricothyreoidei produce tension and elongation of the vocal folds by drawing up the arch of the cricoid cartilage and tilting back the upper border of its lamina; the distance between the vocal processes and the angle of the thyroid is thus increased, and the folds are consequently elongated.
This muscle is innervated by the external laryngeal branch of the vagus nerve.