Part of a woman's reproductive system, the cervix is located in the lower, narrow part of the uterus (womb). The cervix connects the uterus to the vagina and the vagina leads to the outside of the body. During a woman's menstrual period, blood flows from the uterus through the cervical canal into the vagina; during pregnancy, the cervix is tightly closed to help keep the baby inside the uterus. The cervix also produces mucus, which helps sperm move from the vagina into the uterus.