The innermost part of the fallopian tube, passing through the wall of the uterus (the myometrium) to join the isthmus to the endometrial cavity.

The hollow organ, about 10 to 12 centimeters long, that effectively joins the ovary to the uterus on each side. Composed of the fimbrial end, the ampulla, the isthmus and the interstitial segment.

An ectopic pregnancy located in the interstitial segment of the fallopian tube. An especially dangerous form of tubal pregnancy, because the surrounding myometrium of the uterus supports the pregnancy's growth for weeks without causing symptoms; when rupture eventually occurs it can be catastrophic, because a main branch of the main artery to the uterus is torn, with sudden (sometimes fatal) bleeding into the peritoneal cavity.

The narrow, inner part of the fallopian tube, about 3 to 4 cm long; lies between the ampulla and the interstitial segment.

Overcoming a localised obstruction of the isthmus or the interstitial segment of the fallopian tube by pushing a wire or a catheter through it, enabling (in some cases) the tube to be 're-canalised' and so to remain open after being blocked before; it's an attractive alternative to tubal anastomosis and can be performed either during the investigation of tubal infertility with hysteroscopy, laparoscopy and falloposcopy or at the time of carrying out a hysterosalpingogram. Because not all tubes that seem to be blocked are in fact blocked (sometimes a normal tube will not allow fluid to pass through it for hormonal reasons or because of a spasm), care needs to be taken to investigate the tube properly before canalisation is undertaken.

An ectopic pregnancy located in the fallopian tube; most occur in the ampulla, but others can be located in the narrower isthmus or in the interstitial segment.