Isthmus of uterine tube
![](/Images/godic/202501/21/Illu_ovary1405.jpg")
The visible medial third of the uterine tube is the isthmus of uterine tube or isthmus tubae uterinae. It is medially bordered by the intramural portion of the tube that connects to the endometrial cavity and laterally by the ampullary part of the tube.