The ventricularis muscle consists of several small fibers that are bound together and unite the arytenoid cartilage to the side of the epiglottis inside the human throat. These fibers extend parallel with and next to the ventricle wall in the throat. The arytenoid cartilage acts as the attachment points of the vocal cords. The epiglottis, found in the back of the throat, points up at the back of the throat.
Both the arytenoid cartilage and the epiglottis, aided by the ventricularis, work together in the modulation and production of speech. The ventricularis muscles move the arytenoid cartilage, which in turn stretches the epitglottis and allows speakers to create sounds in the back of their throats, as with "h," "l" and most vowel sounds.
Disruption or even failure of the ventricularis muscle often leads to a variety of speech disorders, for example, Dysphonia plica ventricularis, which causes a speaker to speak with a severe straining sound as the muscles in their vocal cords spasm uncontrollably. The ventricularis muscle is also the home of more serious conditions, such as vocal cord polyps, vocal cord hemmorrhage and even throat cancer.
The ventricularis muscles pull on the arytenoid cartilage or the epiglottis or both, positioning each in such a way as to create a sound when air is passed through the vocal cords. Tensing and relaxing this tiny muscle results in the tensing or relaxation of the vocal cords themselves, which in turn affects what we say and how we sound when we're saying it.