Anatomy & Organs

Musculus cricoarytenoideus lateralis – structure, function & diseases

Musculus cricoarytaenoideus lateralis

The lateral cricoarytenoid muscle is a muscle of the larynx . It belongs to the internal muscles of the larynx. It allows the glottis to close .

What is the lateral cricoarytenoid muscle?

The human organism needs a larynx and various coordinated modules for speech and voice formation. At the upper end of the neck to the middle of the neck is the larynx in a vertical form and easily palpable from the outside.

Its movements are controlled by the larynx muscles. The inner and outer muscles of the larynx must be distinguished from each other. The lateral cricoarytenoid muscle is assigned to the internal muscles of the larynx. It plays an important role in voice formation. The larynx is surrounded by various types of cartilage. Visually, they have the shape of a scaffold.

The path of the lateral cricoarytenoid muscle runs obliquely from the cricoid cartilage to the arytenoid cartilage . There he moves the arytenoid cartilage to the midline. This causes the glottis to narrow. The glottis is fissured. It is located between the vocal folds . The process of narrowing causes the vocal cords to relax. The vocal cords must vibrate freely in order to produce a sound. The lateral cricoarytenoid muscle is involved in this.

Anatomy & Structure

Doctors refer to the larynx as the larynx. It consists of fibers, various muscles and cartilage. In order for the larynx to move, it is innervated by various muscles. The muscles are divided into the internal and external laryngeal muscles.The larynx itself can be divided into three areas. They lie vertically one above the other. Above is the supraglottis, or vestibulum laryngis. In the middle there are the glottis or cavitas laryngis intermedia. The inferior area is formed by the subglottis or cavitas infraglottica. The shape of the larynx is formed by a cartilage framework. The cartilages completely envelop the larynx and are differentiated according to the region.

There are four different types of cartilage. These are the Cartilago cricoida, the Cartilago thyroidea, the Cartilago epiglottica and the Cartilagines arytaenideae. The Cartilago cricoida is the cricoid cartilage and the Cartilagines arytaenideae is also known as the arytenoid cartilage or arytenoid cartilage. The processus muscularis belong to the arytenoid cartilage. The lateral cricoarytenoid muscle begins its course at the arcus of the cricoid cartilage. From the upper edge there it runs to the muscular process of the arytenoid cartilage. The lateral cricoarytenoid muscle is supplied by the recurrent laryngeal nerve .

Function & Tasks

In humans, phonation is produced in the larynx. Phonotation is the human voice formation. In order for it to happen, people need different muscles. One of them is the lateral cricoarytenoid muscle. The larynx has a vertical shape and can be divided into several layers. Each of these is surrounded by a framework of cartilage and has different functions.

The cricoid cartilage is in the upper layer and the arytenoid cartilage is in the lower layer. Voice formation takes place in the area of ​​the arytenoid cartilage. If the musculus cricoarytenoideus lateralis tenses, it contracts the processus muscularis of the arytenoid cartilage. These are bony processes. By contracting, the cartilages draw closer to each other. At the same time, the vocal cords also come closer together, since the activity of the muscle causes the glottis to close.

In order to be able to produce a sound, the vocal folds have to come together. In order for the phonation to work, in addition to the training of various components, an interaction of different functions in the organism is required. They include correct hearing , free vibration of the vocal cords, continuous airflow, and the closure of the glottis. The sound of the voice and the color of the voice are generated in the extension tube. This is located in the oral, nasal and pharyngeal cavities and must be free. Airflow passes through the lungs , bronchi , and trachea . Only when all components are in harmony with each other does voice formation take place.


Hoarseness occurs when the lateral cricoarytenoid muscle is impaired . The hoarseness is called dysponia. It causes the vocalization and the timbre to change. Mostly is rough or scratchy. The volume of the sounds produced is usually reduced.The reason for this is that the vocal cords can no longer vibrate freely when they are hoarse. All diseases that have hoarseness as a symptom cause impairments in this region of the body. They include respiratory and throat infections, allergies , or inflammation. A chronic or acute inflammation of the larynx or an inflammation of the trachea triggers a dry cough in addition to the hoarseness . In addition, the airway narrows. The same happens with bronchitis .

Nerve inflammation , damage or failure of the inferior laryngeal nerve results in the lateral cricoarytenoid muscle no longer being sufficiently innervated or not being innervated at all. This leads to a functional failure of the muscle. New tissue growth, benign or malignant, impairs the ability of the lateral cricoarytenoid muscle to function. This can be edema, cyst formation or carcinoma in the neck, throat or larynx area.

They all influence the activities of the vocal cords and phonation. Inhaling toxins or smoking also affects the larynx region. If a patient is intubated under difficult conditions in an emergency, the larynx, the vocal cords and the surrounding vessels and nerves can be damaged. Intubation that lasts for several weeks can also cause trauma to the larynx.

Lisa Newlon
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Hello! I am Lisa Newlon, and I am a medical writer and researcher with over 10 years of experience in the healthcare industry. I have a Master’s degree in Medicine, and my deep understanding of medical terminology, practices, and procedures has made me a trusted source of information in the medical world.