Fallopian tube. Coloured scanning electron micrograph (SEM) of a freeze-fractured section through a Fallopian tube (oviduct). The interior (lumen) of the tube (dark space, upper centre) is lined by a thick, highly-folded mucosal layer. A thin muscle layer surrounds this, best seen as the thin compact line at lower centre. These two layers make up the central and upper region of the image. The outer regions are the serosal outer layer of connective tissue (light brown). The two Fallopian tubes are the muscular tubes through which ova (eggs, the female reproductive cells) pass from the ovaries to the uterus following ovulation. Magnification: x100 at 6x7cm size.