What Does the Cervix Do?

Women typically talk about the cervix in relation to childbirth, or in relation to having a Pap smear. However, many are unaware of what the cervix is and how it functions. Find out more about how the cervix plays an important role in the female reproduction system.

What You Need to Know About Your Cervix

The cervix is the lower portion of the uterus. It is approximately two inches long, and it's tubular in shape.

It widens during childbirth to allow for the passage of the baby. It also allows for the passage of menstrual fluid from the uterus, and sperm needs to travel through the cervix in order to reach the uterus.

The cervix is vulnerable to several health conditions, such as chronic inflammation, polyps, dysplasia, and cancer. Unfortunately, cervical conditions rarely present symptoms in the early stages; therefore, a regular Pap smear from a gynecologist is vital. A Pap smear can identify abnormal cervical changes long before they become cancerous.

cervical cancer diagnosis


Cervical cancer screening guidelines that were updated by the American College of Obstetricians and Gynecologists (ACOG) in April 2021 suggest:

  • Women should have their first Pap smear at age 21.
  • Women aged 21 to 29 years should have a Pap test alone every three years. Primary HPV testing can be considered for the average risk patient aged 25 to 29.
  • Women aged 30 to 65 years should have a Pap test and an HPV test (co-testing) every 5 years. It also is acceptable to have a Pap test alone every three years or primary HPV testing alone every five years (using FDA approved primary testing)
  • Women age 65 or older can stop having cervical cancer screenings if they do not have a history of moderate or severe abnormal cervical cells or cervical cancer, and if they have had either three negative Pap test results in a row or two negative co-test results or negative HPV tests in a row within the past 10 years, if the most recent test were performed within the recommended screening times.
  • Women who have had a hysterectomy should ask their doctor about whether or not they still need screening. The answer depends on several factors, including whether the cervix was removed, why the hysterectomy was needed, and whether there's a history of moderate or severe cervical cell changes or cervical cancer. Even if the cervix is removed at the time of the hysterectomy, if you have a history of cervical cancer or cervical cell changes, you should continue to have screenings for 25 years after the time of your surgery.

Anatomy of the Cervix

Several key components contribute to cervical function. These areas of the cervix are often discussed during pregnancy, Pap smears, and colposcopy exams. It is important to become familiar with them so you can understand possible changes occurring in your cervix. This knowledge will also help you understand tests, like the Pap smear or colposcopy.

  • Endocervical Canal: This is the potential space in the center of the tube of tissue that is the cervix. During a colposcopy, the doctor may take a sample of cells in the endocervical canal. This is called an endocervical curettage (ECC).
  • Ectocervix: This is the lower part of the cervix that protrudes into the vagina.
  • Internal Os: This part of the cervix is closest to the uterus. During pregnancy and childbirth, you may hear the doctor speak about the "os."
  • External Os: This is the opening of the ectocervix.
  • Transformation Zone: This is also called the "TZ" for short. This is the area of the cervix where cervical dysplasia commonly occurs. The transformation zone is often discussed during a colposcopy exam.

Again, having regular Pap smears is imperative to detect any early changes in cervical cells that may lead to cervical cancer; however, you should know that the majority of abnormal Pap smears do not mean you have cancer.

Frequently Asked Questions

  • Where is the cervix?

    The cervix is the lower part of the uterus (womb). It makes up the passage between the vagina and uterus.

  • How long does it take sperm to reach the cervix?

    After ejaculation, it can take sperm only one minute or even less to reach the the cervix. Studies on sperm migration show that sperm take two to 10 minutes to reach the fallopian tubes, the area where fertilization occurs.

  • Is it safe to have a Pap smear while pregnant?

    Yes, it is safe to have a Pap smear while pregnant. The only potential risk is slight superficial bleeding caused by insertion or removal of the speculum (an instrument used to widen the vagina).

  • Do men have a cervix?

    No; at birth, men do not have a cervix. However, transgender men can have one, and may be at risk for cervical cancer.

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4 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. American College of Obstetricians and Gynecologists. Cervical Cancer Screening.

  2. American College of Obstetricians and Gynecologists. Colposcopy.

  3. Custers M, Flierman A, Maas P, et al. Immobilisation versus immediate mobilisation after intrauterine insemination: randomised controlled trialBMJ 2009;339:b4080. doi:10.1136/bmj.b4080

  4. University of California, San Francisco (UCSF) Transgender Care. Screening for cervical cancer in transgender men.