Author: Alexandra Sieroslawska, MD•Reviewer: Dimitrios Mytilinaios, MD, PhD
Last reviewed: October 30, 2023
Reading time: 8 minutes
/images/vimeo_thumbnails/256802349/j0GNRF65HmiyQbNAjCZw_overlay.jpg "Muscles of the larynx (1)")
Recommended video: Larynx[30:35]
Cartilages, ligaments, membranes and muscles of the larynx.
There are many muscles that either make up a certain partof the laryngeal structureinside the neck, or that sit adjacent to it and aid in its function. These muscles produce the movements of the larynx and itscartilages, thus enabling the proper air conduction, speech, movements of the epiglottis and airways protection.
The muscles of the larynx are divided into two groups:
- Extrinsic muscles, which produce the movements of the hyoid bone. These are the infrahyoid (sternohyoid, omohyoid, sternothyroid, thyrohyoid) and suprahyoid muscles (stylohyoid, digastric, mylohyoid, geniohyoid)
- Intrinsic muscles, which move the vocal cords in order to produce speech sounds. They are functionally divided into adductors (lateral cricoarytenoid, transverse arytenoid), abductors (posterior cricoarytenoid), sphincters (transverse arytenoid, oblique arytenoid, aryepiglottic), muscles that tense the vocal cords (cricothyroid), and muscles that relax the vocal cords (thyroarytenoid, vocalis).
This article will discuss the anatomy and function of the laryngeal muscles.
| Extrinsic muscles | Infrahyoid muscles:sternohyoid muscle, omohyoid muscle, sternothyroid muscle, thyrohyoid muscle Suprahyoid muscles:stylohyoid muscle, digastric muscle, mylohyoid muscle, geniohyoid muscle |
| Intrinsic muscles | Adductors:lateral cricoarytenoid muscle, transverse arytenoid muscle Abductors:posterior cricoarytenoid muscle Sphincters: transverse arytenoid muscle, oblique arytenoid muscle, aryepiglottic muscle Tensors: cricothyroid muscle Muscles that relaxvocal cords:thyroarytenoid muscle, vocalis muscle |
Contents
- Extrinsic muscles
- Intrinsic muscles
- Cricothyroid muscle
- Posterior cricoarytenoid muscle
- Lateral cricoarytenoid muscle
- Thyroarytenoid muscle
- Vocalis muscle
- Transverse and oblique arytenoid muscles
- Clinical notes
- Vocal fold paresis
- Sources
+ Show all
Extrinsic muscles
The extrinsic muscles of the larynx are those that are somehow attached to the hyoid bone, be it via origin or insertion and thus move the thyroid cartilage. The infrahyoid muscles are part of and attach to the lower larynx as well as the inferior aspect of the hyoid bone. This muscle group includes the sternohyoid muscle, the omohyoid muscle, the sternothyroid muscle and the thyrohyoid muscle which work to lower the larynx and the hyoid bone.
The suprahyoid muscles are attached to the superior aspect of the hyoid bone and function to fixate the hyoid bone as well as elevate it along with the larynx. The muscles in this group include the stylohyoid muscle, the digastric muscle and the mylohyoid muscle. The stylopharyngeus muscle is not attached directly to the hyoid bone, however it acts indirectly to elevate both the hyoid bone and the larynx.
Want a quick way to learn all the muscles of the head and neck, including those of the larynx? Our head and neck muscle anatomy chart is the revision tool you've been searching for.
Review your knowledge about the extrinsic muscles of the larynx with our quiz below! You can also further refine the quiz selection to fit your needs.
Custom quiz: Extrinsic muscles of the larynx Start quiz
Intrinsic muscles
The intrinsic muscles of the larynx alter both the length and the tension placed upon the vocal cords as well as the rima glottidis. The adductor muscle group is made up of the lateral cricoarytenoid muscles and the transverse arytenoid muscles. The muscles that govern abduction are the posterior cricoarytenoid muscles. The sphincter muscles are the transverse arytenoid muscles, the oblique arytenoid muscles and the aryepiglottic muscles. The cricothyroid muscles are responsible for tensing the vocal cords whilst the thyroarytenoid muscles and the vocalis muscles are responsible for relaxing them.
Cricothyroid muscle
This muscle originates on the anteriolateral part ofcricoid cartilage and inserts into the inferior border of the thyroid cartilage and its inferior horn. It is innervated by the external branch of the superior laryngeal nerve and is supplied by the superior and inferior thyroid arteries, as are all the intrinsic laryngeal muscles. Upon contraction, it lengthens and tenses the vocal ligaments.
Posterior cricoarytenoid muscle
The proximal attachment of this muscle is on the posterior surface of the lamina of the cricoid cartilage and its corresponding insertion point is on the muscular process of the arytenoid cartilage. The recurrent laryngeal nerve innervates this muscle, as it does all the other intrinsic muscles of the larynx, with the exception of the cricothyroid muscle. Its function is to abduct the vocal folds.
Lateral cricoarytenoid muscle
Ailing from the arch of the cricoid cartilage, this muscle distally attaches itself to the muscular process of the arytenoid cartilage. It acts as an adductor of the vocal folds.
Thyroarytenoid muscle
The thyroarytenoid muscle originates from the angle of thyroid cartilage and adjacent cricothyroid ligament. It inserts into the anterolateral surface of arytenoid cartilage, just as the posterior and lateral cricoarytenoid muscles do. As for function, the muscleshortens and relaxes the vocal cords.
Vocalis muscle
The proximal attachment of the vocalis muscle is upon the vocal process of the arytenoid cartilage. It inserts distally upon the vocal ligament and acts by tensing the anterior vocal ligament and relaxing the posterior vocal ligament.
Transverse and oblique arytenoid muscles
Lastly, the arytenoid cartilage acts as a point of origin for both the transverse and oblique arytenoid muscles, which run between the two arytenoid cartilages, as they distally attach to the opposing arytenoid cartilage. Due to their points of attachment, they are able to close the intercartilaginous portion of the rima glottidis.
Action of posterior cricoarytenoid muscle
Functio musculi cricoarytenoidei posterioris
1/4
Synonyms: Abduction of vocal folds, Abductio plicae vocalis
Ready to test your knowledge about the functional anatomy of the intrinsic laryngeal muscles? Try out our larynx quiz below:
Clinical notes
Vocal fold paresis
The recurrent laryngeal nerve is responsible for innervating all muscles of the larynx except the cricothyroid muscle. The clinical term to describe whenone or two of the recurrent laryngeal nerves are injured isvocal fold paresis (also known as recurrent laryngeal nerve paralysis or vocal fold paralysis).
The recurrent laryngeal nerves are involved in breathing, swallowing and vocalization. So if one of the nerves is injured (unilateral injury), it usually results in hoarseness due to the reduced movement of one of the vocal folds.Unilateral injury may also cause minor shortages of breath, and aspiration problems especially with liquids.
A bilateral injury, or when the two recurrent laryngeal nerves are injured,causes the vocal folds to weakenthe air flow, which results in breathing problems,snoring sounds, stridorand fast physical exhaustion. When the vocal folds are billaterally paralyzed, hoarseness rarely occurs.
Sources
All content published on Kenhub is reviewed by medical and anatomy experts. The information we provide is grounded on academic literature and peer-reviewed research. Kenhub does not provide medical advice. You can learn more about our content creation and review standards by reading our content quality guidelines.
References:
- Frank H. Netter, MD, Atlas of Human Anatomy, Fifth Edition, Saunders - Elsevier, Chapter 1 Head and Neck, Subchapter 8 Thyroid Gland and Larynx, Page 45 and 46.
- Neil S. Norton, Ph.D. and Frank H. Netter, MD, Netter’s Head and Neck Anatomy for Dentistry, 2nd Edition, Elsevier Saunders, Chapter 16 The Larynx, Page 429 and 430.
Illustrators:
- Laryngeal muscles - Paul Kim
- Cricothyroid muscle (left lateral view) - Yousun Koh
- Posterior cricoarytenoid muscle (lateral left view) - Yousun Koh
- Lateral cricoarytenoid muscle (lateral left view)- Yousun Koh
- Thyroarytenoid muscle (lateral left view)- Yousun Koh
- Vocalis muscle (lateral left view) -Yousun Koh
- Oblique arytenoid muscle (left lateral view) - Yousun Koh
- Larynx(cadaveric dissection) - Prof. Carlos Suárez-Quian
Muscles of the larynx: want to learn more about it?
Our engaging videos, interactive quizzes, in-depth articles and HD atlas are here to get you top results faster.
What do you prefer to learn with?
VideosQuizzesBoth
“I would honestly say that Kenhub cut my study time in half.”–Read more.
Kim Bengochea, Regis University, Denver
