The word cervix comes from the Latin phrase that means “neck of the womb” and it is the part of the uterus that joins with the top part of the vagina. This area is narrow and conical or cylindrical, protruding up into the upper anterior portion of the vaginal wall. With appropriate medical equipment, about half of the cervix can be seen and the rest is still out of sight as it is too far up into the uterus. The cervix also contains an opening that allows for the passage of menstrual fluid and semen.
Function of the Cervix
- Sphincter. One of the most important functions of the cervix is as the sphincter for the uterus. When a woman is menstruating, the cervix opens slightly, allowing the body to shed the endometrium. Experts believe that it is this stretching that causes cramps and some women experiencing less pain after giving birth due to the widening of the cervical opening. During childbirth, the cervix will dilate up to a diameter of 10 centimeters because of uterine contractions. Short cervix may lead to preterm birth and can be caused by cryotherapy, cold-knife conization, LEEP and other treatments that prevent cervical cancer.
- Sperm Storage. When a woman orgasms, her cervix will convulse and her external os will dilate. Some experts (Mark A. Bellis and Robin Baker from University of Manchester) have proposed that this convulsion and dilation is designed to increase the probability of conception by drawing semen into the vagina and the theory is referred to as “upsuck.” Although other experts (Komisaruk, Whipple, and Beyer-Flores) have shown support for the theory and it has been taught for over a decade, many others (Elisabeth Lloyd) are still skeptical about its validity. It is agreed, however, that after intercourse the cervix is a reservoir for the sperm.
- Barrier. The cervix functions as a barrier to prevent infection of the uterus.
- Lubrication. Cervical mucus provides lubrication for the vagina.