When you enter the vagina with your hand, you can feel the cervical opening. The anterior wall of the vagina is about 9 cm long, and the posterior wall of the vagina is slightly longer, about 10-13 cm. The distance of the cervical opening from the vaginal opening is about 8-9 cm on average. Under normal circumstances, the cervical opening is cylindrical when felt by hand. If there is no history of childbirth and no history of labor, the cervical opening is round, and if a patient has given birth or had an abortion, and if it is a patient with a large month abortion, the cervical opening is often in a zigzag shape.