Synonyms
Vocal folds, plicae vocales Sometimes incorrectly called vocal cords, which actually represent only a part of the vocal folds.
General information
The vocal folds are two tissue structures inside the larynx that are covered by mucous membrane. Between them is the glottis, which is an important part of the voice forming apparatus and is responsible for the production of our voice (phonation).
Structure
The vocal folds are a paired organ. They are made up of three layers: On the very inside is the vocalis muscle: this muscle allows the vocal folds to change in tension and thickness, which is necessary to produce different sounds. It is also in direct contact with the cricothyroid muscle, which can also vary in length and tension, creating a highly differentiated apparatus that regulates both the pitch and volume of the voice.
On the outside of the vocal muscle lies the so-called lamina propria, which can be further subdivided: it is a layer of connective tissue, which in this case is formed from many elastic fibers.
- Into a deep one,
- One middle and one upper section.
From the thyroid cartilage (Cartilago thyroidea) to the arytaenoid cartilage (Cartilago arytaenoidea), this connective tissue forms a band-shaped structure towards the middle, which is called vocal ligament. The overlying surface forms a layer of mucous membrane (mucosa).
In the area of the vocal folds, this layer does not consist of a ciliated epithelium as in the rest of the larynx, but of a multi-layered, non-cornified squamous epithelium. Between this epithelium and the musculature, or more precisely in the upper layer of the lamina propria, there is a narrow space, the “Reinke space”. This space ensures that the connective tissue and the epithelium can shift against each other (marginal edge shift). If a fluid accumulates in this space, it is called a Reinke edema.
The glottis
The glottis (Rima glottidis) is located between the two vocal folds. Depending on the position of the vocal folds, this opening is either typically triangular or slit-shaped or as good as closed. The glottis is widest during breathing, since only air must flow through it.
During the formation of sounds, the vocal folds can be brought into different positions in their relation to each other by the control cartilage and then contracted to different degrees by the vocal muscle, so that the formation of various different pitches and volumes is possible. When speaking, the vocal folds meet several times in the middle. For particularly high tones, the vocal folds can open and close more than a thousand times per second.
