What Is The Cervix?

The cervix is the lower third portion of the uterus which forms the neck of the uterus and opens into the vagina which is also called the endocervical canal. The narrow opening of the cervix is called the os. The cervical os allows menstrual blood to flow out from the vagina during menstruation. During pregnancy the cervical os closes to help keep the fetus in the uterus until birth. Another important function of the cervix occurs during labor when the cervix dilates, or widens, to allow the passage of the fetus from the uterus to the vagina.

The cervix is covered by the epithelium which is made of a thin layer of cells. Epithelial cells are either squamous or columnar (also called glandular cells). Squamous cells are flat and scaly, while columnar cells appear, as indicated by their name, column-like. Having regular Pap smears is imperative to detect early changes to the cervical cells which may lead to cervical cancer; however, you should know that the majority of abnormal Pap smears are due to inflammation or infection.

_Source:

Understanding Cervical Changes: What Is The Cervix; National Institute of Cancer; http://www.cancer.gov/cancertopics/understandingcervicalchanges/page2; accessed 04/18/09.