0 the thin opening between the vocal cords at the top of the larynx (= the organ in the throat), that is closed by the epiglottis when you swallow
States of the glottis : an articulatory phonetic model based on laryngoscopic observations.
Figure 2 presents a video image of a phonating glottis, with glottal vocal folds adducted and ventricular folds and aryepiglottic folds in their open positions.
The glottis cannot be simultaneously constricted and spread, presumably a universal physiologically based restriction.
The glottal vocal folds can oscillate anteriorly along the ligamental glottis, while remaining open posteriorly.
All of these observations present a much more complex picture of states of the glottis than the mono-valve, mono-dimensional glottal continuum model described above.
This is not the case for voiceless plosives, however, and both aspirated and unaspirated voiceless plosives have an abducted glottis throughout oral closure.
Their effect is realised in combination with the vibratory cycles being produced at the glottis.