Histological structure of vocal fold lamina propria in foetal larynx.

Previous investigations of vocal fold lamina propria in adult human larynx have revealed a highly specific organization and distribution of the connective fibres. The authors tried to elicit the developmental characteristics of that process using a material of foetal larynxes, ranging in foetal age from 13 to 23 weeks. The specimens were embedded in paraffin and then serially sectioned in both horizontal and vertical plane. The specific technique of differentiating elastic fibres from collagen fibres was utilized. The distribution and organization of connective tissue in foetal vocal fold lamina propria differed from that in adults and no straight elastic fibres were demonstrated as the first sign of later differentiation.