Cyclical changes in the epithelium of the fallopian tube. Studies with scanner electron microscopy (SEM)

By means of SEM the existence of cyclical changes has been demonstrated on the surface of the tube that is of paramount importance in the biology of reproduction. The frequency of ciliary cells increases under the influence of estrogens, producing erect cilius. Under the influence of progesterone, they are frequent once again, but due to the disappearance of secretory activity of the secretory cells. The days preceding and immediately following ovulation (days 13 to 17) the maximum cellular secretion is observed by virtue of apocrine secretion, characterized by the elimination of part of the cellular cytoplasm, and merocrine secretion brought about by multiple and coarse microvilli. The fluid that is produced during these days serves as a vehicle of sperm transport and prevents the descent of the fertile egg.