A new morpho-functional classification of the Fallopian tube based on its three-dimensional myoarchitecture

The recent direct observations, under scanning electron microscopy (SEM), o f the three-dimensional architecture of myosalpinx in different mammals all ows us classify salpinxes according to the myoarchitecture of their tubo-ut erine junction (TUJ) and isthmus segments. Based upon the myoarchitecture of the outer wall of the TUJ we could find b arrier-like species (rat and sow), sphincter-like species type a (rabbit an d ewe) and sphincter-like species type b (cow and woman). The different arc hitecture of TUJ can be explained by the different nature of the mating pro cess. Based upon the myoarchitecture of the isthmus we could distinguish ty pe 1 (rat) and type 2 (rabbit, ewe, sow, cow and woman) salpinxes. In the l atter the dose fusion of musculature deriving from the meso (extrinsic musc ulature) with the musculature of salpinx (intrinsic musculature) suggests t he existence of a unique mesosalpinx contractile system. The myosalpinx is mostly made up of a single network of muscular fibers. Su ch a plexiform structure, owing to the uneven distribution of fibers, rathe r than producing a series of regular contraction waves, is more likely to g enerate random contraction waves. The random propagation of muscular networ k contraction may deform the plexiform wall of the myosalpinx causing the s tirring of tubal contents. By such a stirring movement the contact between hormones and nutrients and the eggs or embryos is intensified, thus favorin g a correct fertilization and early embryo development. Taken all together, these systematic results probably suggest an additional and rather new fun ction for the musculature of the tube, namely to increase fertility in a la rge number of species.