Each of the two 4-inch fallopian (fuh-LOH-pee-un) tubes extends from the uterus toward an ovary, at the left or the right side of the pelvic cavity (see Figure 3.4). The outside end of each tube is shaped like a funnel, with fringelike projections called fimbriae (FIM-bree-eye) that hover over the ovary. When the egg leaves the ovary, it is drawn into the tube by the fimbriae.
Once the egg is inside the fallopian tube, the movements of tiny hairlike cilia and the contractions of the tube walls move it along at a rate of approximately 1 inch every 24 hours. The egg remains viable for fertilization for about 24 to 48 hours. Therefore, fertilization occurs while the egg is still close to the ovary. After fertilization the zygote begins developing as it continues traveling down the tube to the uterus.
An ectopic pregnancy occurs when a fertilized ovum implants in tissue outside the uterus, most commonly in the fallopian tube (Ramakrishnan & Scheid, 2006). This implantation can rupture the tube and cause uncontrolled bleeding, which is a serious medical emergency. The most common symptoms of ectopic pregnancy are abdominal pain and spotting that occur 6 to 8 weeks after the last menstrual period. Diagnostic tests can establish the presence of an ectopic pregnancy, and medical and surgical procedures are used to treat it (Scott, 2006).