Cervix

The cervix is the lower part of the uterus that opens into the vagina. It is a part of the female reproductive system.

During a menstrual period, blood flows from the uterus through the cervix, down the vagina, and out of the body.
During ovulation, the cervix makes mucus that helps sperm move up into the uterus.
During pregnancy, the cervix is tightly closed to protect the baby. But later the cervix opens up so the baby can pass through the vagina during childbirth.