Objective: To provide a definitive settlement of data on the architecture of myosalpinx in the sow in consideration of controversial data existing in literature.
Study-design: To allow direct visualization of muscular architecture, segments of tube from fifteen sows were investigated by means of scanning electron microscopy after the removal of interstitial connective tissue with NAOH digestion.
Results: In the extramural portion of the tubo-uterine junction, in the isthmus and ampulla, the myosalpinx is mainly constituted by oblique bundles of variable length, which run around the tube and merge into the surrounding musculature, giving origin to a plexiform arrangement. In the ampulla the fibers join in short bundles variously oriented.
Conclusion: The three-dimensional architecture of the sow myosalpinx consists of muscular bundles independent of one another which follow multiple spatial arrangements and form a complex network. Such a muscular structure is likely more suitable for stirring rather than pushing the embryo and gametes.