Sperm in a fallopian tube, SEM - stock photo

Sperm in a fallopian tube. Coloured composition scanning electron micrograph (SEM) of human sperm travelling through a fallopian tube (oviduct) of a female. After ejaculation sperm may stay alive in the female reproductive tract for about 48 hours. At the beginning of their journey in the vagina the sperm number about 300 million but only a few thousand survive to reach the ampullary region of the two female fallopian tubes where fertilisation of an egg may occur. The inner walls of the fallopian tube contain simple columnar cells of two types: ciliated cells (orange, with hair-like cilia), and secretory cells (pink).