A Blocking Mechanism in the Cow Oviduct

Summary. A mechanism is present in the oviduct of the cow that prevents the escape of oviduct fluid into the uterus. Oviducts that were ligated at the ovarian end, soon after ovulation, become greatly distended with accumulated oviducal fluid. Distension remained until about 72 hr after ovulation and then receded. The isthmic musculature, rather than the tubo-uterine junction, was responsible for blockage. Insufflation of the oviduct indicated that the uterine 3 to 4 cm of the isthmus was most influential in resisting gas passage through the tube.