Figure Fig. 4.
Normal uterus of a 20‐year‐old subject. Serial images of uterine peristalsis captured with a 3‐s interval. a JZ at the area of internal ostium shows a thicker and darker signal than that in other areas. b, c The thick and dark JZ has moved with time and has reached the fundus. d This signal change means that subtle contraction of the subendometrial myometrium has occurred and may help convey the sperm from the cervix to the fundus