Quick Facts
Origin: Cricoid arch of cricoid cartilage.
Insertion: Oblique part: inferior horn of thyroid cartilage; Straight part: inferior border of thyroid lamina.
Action: Lengthens and alters tension of vocal folds.
Innervation: External branch of superior laryngeal nerve.
Arterial Supply: Cricothyroid branch of superior thyroid artery.
Related parts of the anatomy
Origin
The cricothyroid muscle sits on the external aspect of the anterior larynx and arises from the cricoid arch.
Insertion
The muscular fibers of the cricothyroid courses posteriorly where its fibers run in two different directions, thus, forming the oblique and straight parts. The oblique part passes in a posterolateral direct and attaches to the inferior cornu of the thyroid cartilage. The fibers of the straight part of the cricothyroid muscle pass superiorly and attach to the inferior border of the thyroid lamina.
Key Features & Anatomical Relations
The median cricothyroid ligament separates the right and left cricothyroid muscles.
Actions
Overall, the cricothyroid muscle reduces the size of the space between the cricoid and thyroid cartilages. This action lengthens and alters the tension of the vocal folds (Standring, 2016).
References
Standring, S. (2016) Gray's Anatomy: The Anatomical Basis of Clinical Practice. Gray's Anatomy Series 41st edn.: Elsevier Limited.
