Fallopian tube, also called oviduct or uterine tube, is either of a pair of female reproductive organs through which eggs from the ovaries pass to the uterus. The fallopian tube is the site where an egg is usually fertilized by the male’s sperm. See Reproduction, Human (The human reproductive system).
In women, each tube measures about 4 inches (10 centimeters) in length. The tubes are lined with two types of cells, ciliated cells and secretory cells. The ciliated cells have cilia (hairlike structures) on their surface that help carry the egg into and through the tube. The secretory cells produce secretions that nourish the egg.
After entering the tube, an egg must be fertilized by sperm within about 24 hours or it dies. Sperm enter the tube through the uterus, and contractions of the tube help move the sperm toward the ovary. The egg remains in the fallopian tube for about 72 hours before passing into the uterus. An ectopic pregnancy occurs when a fertilized egg does not pass to the uterus, but attaches and begins to grow inside the fallopian tube. The baby cannot survive such a pregnancy, which may also be fatal to the mother if untreated.
Blockages in the fallopian tube may result from diseases or birth defects and can cause infertility. In some cases, the blockage can be removed surgically. A woman with blocked tubes may become pregnant through a procedure called in vitro fertilization. In this procedure, eggs collected from the ovaries are fertilized in a laboratory dish with sperm and then inserted back into the uterus.