short, muscular section at the end of a female’s oviduct; after the uterus has finished forming the shell that surrounds the embryo (or the unfertilized ovum), yolk, albumen, and membranes, contractions (induced by the hormone arginine vasotocin) push the egg into the vagina, which helps push it into the middle section of the cloaca to be laid; has a robust immune component that prevents microbes in the cloaca from infecting the egg; an area between the vagina and the uterus, the uterovaginal junction, can store sperm from a male to be moved up the oviduct later to fertilize an ovum in the infundibulum