Vocal folds

The vocal cords (also vocal folds, Latin plica vocalis ) are paired oscillatory structures in the larynx. They are an essential part of the voting forming apparatus ( glottis ) of the larynx, consisting of the coated epithelium of vocal fold, the actual vocal cords ( vocal ligament ), the musculus vocalis and the arytenoid cartilages each of both sides. The vocal folds are on both sides during phonation ( voice production ) by blowing from the chest vibrated ( Bernoulli effect ) and thus form the primary sound of the voice.

Design and function

The gap between the vocal cords is called the glottis ( rima glottis ). The rear ends of the vocal folds are the two arytenoid cartilages ( arytenoid cartilage Latin, Mz cartilages arytaenoideae ) respectively, which regulate each other, the position of the vocal folds. When breathing, the vocal cords are wide open, so that the glottis is replaced by a characteristic triangular shape. The width of the glottis or the degree of constriction is important for the articulation of speech sounds. Through the musculus vocalis a change in vocal fold tension and vocal fold thickness can be achieved. In conjunction with the musculus cricothyreoideus which also changes the tension and length of the vocal cords, results in a control loop more sensitive, with the aid of the volume and pitch of the human voice is adjusted. At this loop is a number of other muscles involved to varying degrees.

About the vocal folds are found on both sides of the bag folds ( plicae vestibular ), which are also called "false vocal cords ". Under certain pathological conditions, the vestibular folds are used for voice training, what a rough and pressed sounding voice has the consequence ( vestibular folds voice ).

If an opera singer sings a particularly high note, open and close the vocal folds more than 1000 times per second. If the voice through a glottic closure (even short-term laryngeal closure ) is interrupted, creating a glottal stop, for example, before the "u" " judge " in and before all vowels in initial position, as in "but."

The vocal cords can be examined with a laryngoscope or a laryngoscope. When laryngoscopy can be assessed by using a stroboscope the vibration expiry of the vocal cords. For functional analysis, the vocal cord vibrations can be recorded with a laryngograph.

Fabric composition

The vocal folds have a layered structure. The basis is the vocal muscle (musculus vocalis ), is about the rich in elastic fibers lamina propria. It forms from the thyroid cartilage to the arytenoid a band-like, the musculus vocalis resting structure, the vocal ligament, the actual " vocal cords ". The surface of the vocal folds and the inner surface of the arytenoid cartilage is of a mucous membrane ( mucosa) with a stratified squamous epithelium, in contrast to the rest of the larynx, which is lined by a ciliated epithelium. Consists of the vocal cord surface between the epithelium and connective tissue, a narrow gap, Reinke's space above which allows a displacement of the epithelium over the connective tissue ( border edge shift ). A (pathological ) accumulation of gelatinous fluid in Reinke's space is called Reinke's edema.

Hirano, 1981, grouped the layers of the vocal folds and thus developed the body- cover model (Table 1) with the cover- Transition -body functional units. This three-and five-layer model and allocated to the different layers of different mechanical properties ( eg density, elasticity, consistency) are one of the foundations for understanding the movements within the vocal folds.

Table 1: layer structure of the vocal folds and functional classification according to the body - cover model:

Special features in the terminology

Colloquially, the vocal folds are also called vocal cords, although the actual vocal cord is formed only by the epithelium and the upper fiber layers.

In some disciplines, such as phonetics, the term glottis is " glottis " are synonymous.