Uterotubal junction--morphology and clinical aspects.

A morphological and histological study of the uterotubal junction was undertaken in order to explain its behaviour in various clinical conditions related to fertility and sterility. The study comprises 150 uterotubal junctions obtained from 75 uteri removed at surgery from women of reproductive age-group. In the study the cornua were subjected to hysteroscopy, hysterosalpingography, naked eye dissection, and light microscopy with serial sectioning. The study reveals the following: The uterotubal junction is the same as the intramural portion of the tube which commences at the tip of an endometrial funnel and ends at the outer border of the uterus to become the isthmus. The length of the intramural tube is, on an average, only 8 mm. Its course is either straight, arched, or convoluted. Peculiar to this part of the tube are the autochthonous muscle layers-an inner longitudinal immediately surrounding the mucosa and an outer circular layer. The uterine musculature, which is fairly thick around the endometrial funnel, suddenly reduces markedly in thickness as the isthmus approaches. We attempt to explain the behaviour of this area in various clinical conditions in the light of the histoanatomic findings.