ABSTRACT
The present study aimed at providing a detailed morphological and ultrastructural features of the isthmic part of the tube at different phases of menstrual cycle. The women undergoing hystrectomy with bilateral salpingectomy at Benha University Hospital were included in this study. Preoperative blood samples were obtained from patients and assayed for serum estradiol and progesterone to help in the accurate dating of the cycle phases. The specimens of isthmic part were transported immediately to the laboratory, and prepared for both light and electron microscopic study. At the early and mid-follicular phases of the cycle, increased number of both ciliated and secretory cells was detected. However, in the late follicular phase secretory activity was much more obvious, as evident by decreased ciliation and appearance of distended secretory cells. At the luteal phase of the cycle profound surface changes have been taken place where secretory cells dominate and cilia became prominent and erect. The postmenopausal endosalpinx presented a flattened surface epithelium with both ciliated and non-ciliated cells