Posterior glottis. Morphological study in excised human larynges.

Two sets of investigations were conducted with excised human larynges. The glottis was closely observed and photographed from above and below in three conditions: neutral, adduction, and abduction. The structure surrounding the posterior glottis was histologically investigated in the same three conditions. The results are as follows. The structure surrounding the posterior glottis consists of three portions: the posterior wall of the glottis, the lateral wall of the posterior glottis, and the cartilaginous portion of the vocal fold. During vocal fold adduction, the posterior part of the larynx closes completely not at the glottis but at the supraglottis, resulting in formation of a conic space in the posterior glottis that can be viewed only from below. The posterior glottis accounts for approximately 35% to 45% of the entire glottic length and 50% to 65% of the entire glottic area. The mucosa of the posterior glottis has ciliated epithelium. The lamina propria consists of two layers. The posterior glottis can be regarded as a respiratory glottis.