Thyro-Arytenoid (Musculus thyroarytenoideus)
Educational content only — not medical advice.
Anatomy
The thyro-arytenoid is a broad, thin intrinsic laryngeal muscle lying parallel to and lateral to the vocal fold. Originating from the internal surface of the thyroid cartilage angle, its fibers pass posteriorly to insert into the anterolateral surface and muscular process of the arytenoid cartilage. It relaxes the vocal folds and functions as a primary protective sphincter of the larynx.
Origin & insertion
From the inner surface of the thyroid cartilage angle and cricothyroid ligament to the anterolateral surface and muscular process of the arytenoid cartilage.
Action
Shortens and relaxes the vocal folds by drawing the arytenoid cartilages anteriorly; constricts the laryngeal inlet during swallowing.
Innervation
Recurrent laryngeal nerve (branch of vagus nerve, cranial nerve X).
Clinical notes
Focal dystonia affecting the thyro-arytenoid muscle produces adductor spasmodic dysphonia, marked by strained, strangulated voice breaks treated with targeted botulinum neurotoxin injections.
Related structures
Educational references
FAQ
What is the role of the Thyro-Arytenoid?
The thyro-arytenoid is a broad, thin intrinsic laryngeal muscle lying parallel to and lateral to the vocal fold. Originating from the internal surface of the thyroid cartilage angle, its fibers pass posteriorly to insert into the anterolateral surface and muscular process of the arytenoid cartilage. It relaxes the vocal folds and functions as a primary protective sphincter of the larynx.
Why is the Thyro-Arytenoid clinically important?
Focal dystonia affecting the thyro-arytenoid muscle produces adductor spasmodic dysphonia, marked by strained, strangulated voice breaks treated with targeted botulinum neurotoxin injections.
Source & license
BodyParts3D, © The Database Center for Life Science licensed under CC Attribution 4.0 International (https://creativecommons.org/licenses/by/4.0/). license details