english: It begins as a straight tube along the center of the embryo, but when the embryo  is around three weeks old, the tube starts to bend into a c-shape and rotate towards  the right side of the body.
non_english: Ono nastaje kao ravna cevčica u središtu embriona, ali kad embrion ima oko tri nedelje, cevčica počinje da se savija u obliku slova c i rotira se prema desnoj strani tela.