When you enter the vagina with your hand, you can feel the opening of the cervix. The anterior wall of the vagina is about 9 cm long, the posterior wall of the vagina is slightly longer, about 10-13 cm, and the distance between the opening of the cervix and the opening of the vagina is about 8-9 cm on average, so that the cervical opening can be felt by hand. Under normal circumstances, the cervical opening is cylindrical when felt by hand, if there is no history of labor and delivery, the cervical opening is rounded, if the patient has given birth or had an abortion, and is a patient with a large-month abortion, the cervical opening is often in the shape of a zigzag, which is normal, and the majority of the cervix has a smooth surface.