Animated scanning electron micrograph (SEM) of the fimbriae of a fallopian tube. Fimbriae are the folds at the opening (ostium) of a fallopian tube, next to an ovary. They help to guide a newly-released ovum (egg cell) into the tube itself. One fallopian tube runs from each ovary into the uterus (womb). Ova travel down the tubes into the uterus. If they encounter sperm on the way they may be fertilised, in which case they implant into the uterus wall and pregnancy begins. If not, they are expelled from the body in the next menstrual period.