FALLOPIAN TUBES The two fallopian tubes are oviducts which extend from the ovaries to the cornua of the uterus, one on either side. Each lies in the free upper border of the broad ligament and, when straightened, is 10 cm in length. Its lumen communicates with the uterine cavity at its inner end and with the peritoneal cavity at its outer and thus provides the final section of an open or potentially open canal which leads from the exterior to the abdominal cavity. The fallopian tube is divided into four pas Interstitial or Intramural Pa This is only 1-2 cm in length and is the pa which traverses the uterine wall. It has a very narrow lumen (1 mm in diameter) and is different from the remainder of the tube in that it is without a peritoneal coat, and in that the outer longitudinal muscle has disappeared to cover the uterus. Isthmus This is the straight and narrow poion adjacent to the uterus and measures 2-3 cm. It has thick walls but the lumen is so narrow that it will only admit the finest probe (1-2 mm in diameter). Ampulla This is the wider, thin-walled and touous outer poion, approximately 5 cm in length, which leads to the infundibulum. Infundibulum This is the trumpet-shaped outer end with an opening into the peritoneal cavity (abdominal ostium). The latter is surrounded by fronds or fimbriae, one of which is longer than the others and is directed towards the ovary (fimbria ovarica). The fimbriated extremity is free of the broad ligament and curls back on itself so that its fimbriae aim to embrace the ovary like the tentacles of an octopus; this is impoant to feility. jeffcoate&;s principles of gynaceology;7th edition;pageno 29