Fibroblasts in human vocal fold mucosa.

Fibroblasts in two portions of the vocal fold mucosa, the macula flava (MF) and Reinke's space (RS), were investigated by means of transmission electron microscopy. Five adult and five newborn larynges from autopsy cases were subjected to study. Both in adults and newborns, fibroblasts in the MF tended to be stellate in shape, to have a small nucleus/cytoplasm (N/C) ratio, and to have a well developed rough endoplasmic reticulum (rER) and Golgi apparatus (GA). They were active in producing collagenous and elastic fibres. Most fibroblasts in RS were oval in newborns and spindle-shaped in adults. They had a large N/C ratio and less developed rER and GA, indicating that they were inactive in producing fibres. We postulate that many fibroblasts in the newborn and infant MF contribute to the development of the vocal ligament, many of those in the adult MF participate in the metabolism of the vocal ligament, and many of those in RS of both age groups are activated when the vocal fold tissue is injured.