The word cervix has only recently come to refer almost exclusively to the portion of the uterus that narrows between the vagina and the body of the uterus (corpus uteri). Cervix is from the Latin for “neck” and uterus is from the Latin for “womb.” Thus, the cervix is the neck of the womb–strange imagery, non? Anyway, what exactly is it that the cervix does? Does it do anything special if it is only an extension of the uterus? Of course it does something special!
The cervix, during an average menstrual cycle, goes through several important changes. Generally the cervix is stiff (like the texture of your nose) and positioned high with a small opening. However, during ovulation, the cervix becomes softer and lower with a wider opening. This quality of the cervix during ovulation promotes the movement of the sperm in their upward journey toward the released ovum (egg). Also, during orgasm the cervix convulses. Some research has linked this movement of the cervix as an evolutionary means of improving the chances of conception, though other scientists have argued that there is no correlation between cervical orgasm and increased rates of conception. So, just because you don’t orgasm during sex doesn’t mean you won’t get pregnant or are any less likely to get pregnant. The cervix also produces the mucus or normal vaginal discharge that varies over a woman’s menstrual cycle.
The cervix also plays a key role in detecting gynecological cancers. As discussed yesterday, the cervix is the object of Pap smears testing for cancerous and pre-cancerous cells. In this procedure–if you are unfamiliar, in which case you need to get a Pap smear A.S.A.P.–a clinician collects epithelial cells from the cervix and sends them to a lab where they are studied for abnormalities. The greatest cause of cervical cancer, the most common form of gynecological cancer, is the human papilloma virus (HPV). HPV has also been proven to cause neck cancer (remember the Latin lesson?). Thankfully, researchers at my own university helped discover a vaccine that prevents most types of HPV and thus prevents most incidences of cervical cancer. So when you are getting that Pap smear make sure to ask about getting an HPV vaccine.
The cervix also plays an integral part in the maintaining of a pregnancy. During pregnancy, the cervix develops a mucus plug that secures the fetus, placenta, and the amniotic fluid from bacteria and other “intruders.” Close to delivery the cervix begins to thin (or can be thinned by pharmaceuticals such as Cervidil, a formulation of dinoprostone) in preparation for birth. The uterus contracts during labor to widen the opening of the cervix up to ten centimeters in order to allow the passage of the baby through the cervix down into the birth canal.
Some women have weaker than average cervices and require a procedure called a cerclage during pregnancy in order to bolster the cervix’s support of the growing fetus. A new method has recently been developed to make a cerclage more effective by entering through the abdomen rather than the vagina. A cerclage, essentially, sutures the cervix in order to make it firmer for the duration of the pregnancy. The cerclage should be undone before the onset of labor in order to keep the cervix from rupturing. Elective cerclage is extremely effective (around 90% success) though emergency cerclage is less effective (usually because the cervix has dilated too much) at about 50% success.
Well, that is a brief outline of the functions of the cervix. The cervix is quite an interesting and indispensable part of our bodies. Do you have more to add or have a burning question? Leave it in the comments, thanks!