Full Fallopian Tube Description
[Continued from above] . . . with muscle contractions, force the ovum down the funnel's small end, which opens into the uterus. After sexual intercourse, sperm swim up this funnel from the uterus. The lining of the tube and its secretions sustain both the egg and the sperm, encouraging fertilization and nourishing the egg until it reaches the uterus. If an egg splits in two after fertilization, identical or maternal twins are produced. If different sperm fertilizes separate eggs, the mother gives birth to un-identical or fraternal twins.