Development of ciliated cells in the human fetal oviduct: an ultrastructural study.

Prenatal development of ciliated cells in the human fallopian tube was studied by light and electron microscopy in specimens obtained from 12 fetuses, aged 12-40 weeks. On light microscopy, transverse sections of the ampullary portion of the tube revealed a slit-like lumen at 12 weeks. The lumen began to fold by 15 weeks, and formed the typical villous structures by 31 weeks. On electron microscopy, the epithelial cells contained a large number of sub- and supranuclear glycogen particles until 18 weeks and an occasional solitary cilium. At 20-22 weeks, instead of glycogen particles, cytoplasmic organelles such as mitochondria, rough endoplasmic reticula and Golgi apparatus were well developed, and some cells possessed cilia with a 9 + 2 microtubular structure. Between 22 and 31 weeks, ciliated cells were sporadically observed. At 31 weeks, the epithelial cells accumulated a large number of sub- and supranuclear glycogen particles. Afterwards, numerous ciliated cells with well-developed cytoplasmic organelles were observed by 40 weeks.