The cricoarytaenoideus lateralis muscle is a muscle of the larynx. It belongs to the internal laryngeal muscles. Through it, the closure of the glottis is made possible.
What is the cricoarytaenoideus lateralis muscle?
For speech and voice formation, the human organism requires a larynx and various coordinated modules. At the upper end of the throat to the middle of the neck, in a vertical form and easily palpable from the outside, is the larynx. Its movements are controlled by the laryngeal muscles. The inner and outer laryngeal muscles must be distinguished from each other. The cricoarytaenoideus lateralis muscle is assigned to the inner laryngeal muscles. It has an important function in voice production. The larynx is surrounded by various cartilages. Visually, they have the shape of a framework. The path of the lateral cricoarytaenoid muscle runs obliquely from the cricoid cartilage to the stellate cartilage. There, it moves the stellate cartilage toward the midline. This causes the glottis to narrow. The glottis is cleft-shaped. It is located between the vocal folds. The process of narrowing causes the vocal cords to relax. To produce a sound, the vocal cords must vibrate freely. The cricoarytaenoideus lateralis muscle is involved in this.
Anatomy and structure
Physicians refer to the larynx as the larynx. It consists of fibers, various muscles, as well as cartilage. In order for the larynx to move, it is innervated by various muscles. The muscles are divided into the inner and outer laryngeal muscles. The larynx itself can be divided into a total of three areas. They lie vertically one above the other. At the top is the supraglottis or vestibule laryngis. In the middle there is the glottis or cavitas laryngis intermedia. The lower area is formed by the subglottis or cavitas infraglottica. The shape of the larynx is formed by a cartilaginous framework. The cartilages completely envelop the larynx and are differentiated according to the region. There are four different cartilages. 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 called the stellate cartilage or ary cartilage. The stellate cartilage includes the processus muscularis. The lateral cricoarytaenoid muscle begins its course at the arcus of the cricoid cartilage. From the upper edge there, it moves to the processus muscularis of the articular cartilage. The lateral cricoarytaenoid muscle is supplied by the recurrent laryngeal nerve.
Function and Tasks
Phonation in humans is produced in the larynx. Phonation is the formation of the voice in humans. In order for it to occur, humans require various muscles. One of them is the lateral cricoarytaenoideus muscle. The larynx has a vertical shape and can be divided into several layers. Each of them is surrounded by a framework of cartilage and has different functions. The upper layer contains the cricoid cartilage and the lower layer contains the stellate cartilage. The voice is formed in the area of the stellate cartilage. When the cricoarytaenoideus lateralis muscle tenses, it contracts the processus muscularis of the stellate cartilage. These are bony processes. The contraction brings the cartilages closer together. At the same time, the vocal cords also come closer, as the action of the muscle causes the glottis to close. In order to produce a sound, the vocal folds must come closer together. In order for phonation to function, an interplay of different functions in the organism is required, in addition to the training of various components. These include proper hearing, the free vibration of the vocal cords, a continuous flow of air and the closing of the glottis. The vocal sound and color are produced in the embouchure tube. This is located in the oral, nasal and pharyngeal cavities and must be free. The airflow passes through the lungs, bronchi and trachea. Only when all components are in harmony with each other does voice formation occur.
Diseases
When the cricoarytaenoideus lateralis muscle is impaired, hoarseness occurs. Hoarseness is referred to as dysponia. It causes vocalization and timbre to change. Usually is raspy or scratchy. The volume of the sounds produced is usually decreased.The reason for this is that the vocal cords can no longer vibrate freely during hoarseness. All diseases that have hoarseness as a symptom cause impairment in this region of the body. They include infections of the respiratory tract and throat, allergies or inflammations. Chronic or acute laryngitis or inflammation of the trachea cause irritable cough in addition to hoarseness. In addition, the airway narrows. The same happens with bronchitis. Nerve inflammation, damage or failure of the inferior laryngeal nerve leads to insufficient or no innervation of the lateral cricoarytaenoid muscle. This results in a loss of function of the muscle. A benign or malignant neoplasm of tissue impairs the ability of the cricoarytaenoideus lateralis muscle to function. These can be edema, cyst formation, or carcinoma of the throat, pharynx, or larynx. They all affect the activities of the vocal cords and phonation. Inhalation of toxins or smoking also affects the laryngeal region. If a patient is intubated under difficult conditions during an emergency, damage to the larynx, vocal cords, and surrounding vessels and nerves may occur. Intubation that continues for several weeks can also cause trauma to the larynx.
