From Encyclopedia of Sex and Sexuality
The lowest portion of the uterus. Normally, the cervix is about one inch long. At birth, a female infant’s cervix is relatively large in comparison with the rest of the uterus, however, with the hormonal changes of puberty, the cervix grows proportionally smaller than the rest of the uterus. The cervix forms a short transitional zone between the uterus body and the vagina. A portion of it lies above the level of the vaginal vault (supravaginal cervix) and a portion lies exposed within the vagina. The cervix is made up of connective tissue with a small amount of elastic tissue and smooth muscle fibers. It is lined with mucus-producing cells.
Being the lowest portion of the uterus, the cervix plays an important part in pregnancy. It acts as a stopper, holding the pregnancy intact until term. The term “incompetent cervix” is applied to a painless dilatation of the cervix during the midtrimester of pregnancy, followed by rupture of the membranes and subsequent expulsion of the fetus (miscarriage). The causes of cervical incompetence are obscure, but they apparently include a variety of causative factors. Previous trauma to the cervix due to a D & C (dilation and curettage), amputation, conization, cauterization, or traumatic delivery appear to be factors in some cases. There are also instances of congenital structural defects, uterine anomalies, and abnormal cervical development associated with in utero diethylstilbestrol (DES) exposure. After diagnosis of cervical incompetence, the generally accepted treatment is surgical. A purse-string is sutured around the cervix at 12–14 weeks gestation and removed when fetal maturity is achieved—usually after thirty-seven weeks of gestation.
Inflammation of the cervix (cervicitis) is quite common. The cervix is constantly exposed to trauma, for example, childbirth and coitus. The abundant mucus secretion in conjunction with the bacterial flow of the vagina bathe the cervix, creating a situation conducive to infection. However, only an occasional woman will be symptomatic and require treatment.
Cancer of the cervix has been studied in great detail, and several studies have shown that the disease is found more often in women of low socioeconomic status, or who first experienced coitus at an early age, female prostitutes, women having coitus with many partners, and possibly women who are infected with human papilloma virus (HPV) (see also cervical cancer).
Since most lesions appear without symptoms and are not easily detectable on examination, the Pap smear—a routine screening of cervical cells—is very important. The Pap smear is a simple clinical test which is easy for the physician to administer and free of discomfort to the patient. It is a screening measure and enables tissue documentation of the earliest development of cervical cancer. The Pap smear has a high detection efficiency, which permits treatment at an early stage, when cure is almost certain.