What Does the Cervix Do?

Learn More About the Cervix's Role in Female Reproduction

The cervix is an important part of the female reproductive tract. While it is in reality part of the uterus (the lower third), its functions qre quite different...

Women typically talk about the cervix in relation to childbirth, or in relation to having a Pap smear. Yet the anatomy of the cervix is more complex than simply an opening between the uterus and vagina, and there are several parts. These regions are important to understand when it comes to medical conditions involving the cervix such as dysplasia and cancer. During pregnancy, conditions such as an incompetent cervix imp.....

cervix uteri (womb's neck)

quseitons asked: what does the cervix do

and there are a number of medical conditions both during and separate rom pregnancy that may affect the cervix.

Anatomy of the Cervix

The cervix is really a part of the uterus, though it is usually discussed as its own entity due to the function it plays. The cells of this region of the uterus are also different such that cancers of the cervix and uterus are treated quite differently.

roughly the lower third of the uterus

2 cn to 3 cm in length (around 1 inch)

appears like a turkey neck

latin name literally means neck of hte uterus

cyclinder shaped

similar in width

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

Parts of the Cervix

The cervix is not one single entity but is rather broken down into several different parts. These include the:

  • Endocervix
  • Ectocervix projects into the vagina

Endocervical canal .....

Endocervix inner part that leads to the uterus

opening into uterus internal os, opening into vagina external os

  • 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. squamocolumnar junction This area changes through life. In childhood, the junction is on the exposed vaginal part of the cervix. During puberty, the tranformation zone is created ...

((((((((((((((((((((((((There are three parts of the cervix:The inner part, which can only be seen from inside the vagina, is called the ectocervix. The center of the ectocervix can open, creating a passage between the uterus and vagina.

  1. The endocervix, also called the endocervical canal, is the passage between ectocervix and the uterus.
  2. The point at which the endocervix and ectocervix meet is called the transformation zone.)))))))))))))))

ectocervix is what can be visualized during a pap smear, and external os

In pregnancy, station (cervix position)


cervix during pregnancy...closed

During puberty and pregnancy, the columnar cells that line the endocervix push out into the area of the ectocervix. Since they are then exposed to the acidic environment of the vagina, the columnar cells are changed to squamous cells (in a process called metaplasia).

finish below

this area where the cells is called the transformation zone


What does the cervix actually do?


1 connects uterus to birth canal (vagina)

  1. allows passage of menstrual blood
  2. helps protect baby from outside during pregnancy

mucous helps...

passage of menstrual blood

production and secretion of cervicall mucous

thin - hastens pregnancy

thin mucous helps sperm swim through the cervix

mucous thicker in other parts of the menstrual cycle helping to prevent microorganisms from passing through

thick mucous plug, helps protect baby during rpegnancy

mucous thick during pregnancy, doesn't allow sperm to enter uterus

often passed before labor begins "bloody show"

The os is the narrowest part of the cervix

Cells and Transformation Zone


epithelial cells

squamous .... squamous cell carcinoma thin fish scale appearance

canal single layer of these ... columnar (glandular) when ... adenocarcinoma tall like columns

The transformatin zone is the area where these two types of cells meet, also called the squamocolumnar junction

the term transformation zone is used to describe the process in which columnar cells are changed or "transformed" into squamous cells. This occurs during puberty and during pregnancy

most cancers occur in the transformation zone

transformation zone lies between the ectocervix and endocervix

cells surrounded by a thick layer of muscle tissue and then connective tissue

plus muscle tissue

texture changes during dilation in pregnancy and during each menstrual cycle

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.

Visualizing the Cervix

during a pap smear using a speculum... can see better during a colposcopy

can feel yourself

Function and Role in Childbirth

The cervix plays several roles in women at different stages of her life. During menstruation, it allows for the passage of the menstrual fluid from the uterus. During fertilization, it allows for the passage of sperm into the uterus and upwards to the fallopian tubes. In childbirth, it widens (dilates) to allow passage of the baby from the uterus to the outside world.

dilates from closed to 10 cm to allow the baby's head to fit through also thins so that it is no longer around 1 inch but almost paper thin

once completely dilated, women are allowed to push (if pushing occurs before complete dilatation, chance of cervical tear)

cervix also (in addition to thin mucous) becomes softer during ovulation

doctors can check for ferning

cervix moves anteriorly as it dilates

Medical Conditions

(address can you have pain in your cervix)

Though you may hear about cervical cancer as a reason to have a Pap smear, there are a number of medical conditions that can affect the cervix both during and aside from pregnancy.



abnromal cervix mucous 3 percent to 8 percent of infertility

cervical agenesis

Cervical Ectropian (A Benign Condition)

During puberty and pregnancy the area protrudes out and exposes the columnar cells to...

A cervical ectropion (also called cervical erosion) occurs when the columnar cells are exposed to the acidic environment of the vagina. It is a normal finding in young women, especially young women on birth control pills, but can appear red and look similar to an infection (such as chlamydia) or even cervical cancer when seen by someone unfamiliar with the condition. Bleeding may also occur, especially bleeding after intercourse (postcoital bleeding).

reddish area around os

Cervical Stenosis ofrten due to trauma

Childbirth Related Conditions

Problems with the cervix may lead to infertility, but once a woman is pregnant, other issues may occur.

Incompetent Cervix: An incompetent cervix is one of the causes of premature births. xxx If the condition is suspected ahead of time, a procedure called a cerclage may be done in which the cervix is literally sewn shut.


responsible for roughly 25 percent of late-term miscarriages

Cervical Tears: While vaginal tears and skin tears are more common, the cervix may also be torn during childbirth.

Cervicitis (inflammation)

often due to STDss,

chlamydia gonorrhea


pid occurs when the infection continues to spread upwards and invovles the uterus and fallopian tubes

Cervical Polyps - 2 to 5 percent of women

Cervical Warts (HPV)


582024 better article on decoding abnormal Pap smear

the majority of abnormal Pap smears are due to inflammation or infection.

Cervical Cancer

Cancer of the cervix is often preventable with regular Pap smears, and treatment of dysplasia if it occurs. That said, an estimated x number of women develop cervical cancer each year and x die from the disease.

85 percent squamous cell, 15 percent adenocarcinoma - both related to HPV, percent adenocarcinoma increasing

Two types


the cervix has nerve endings

may not have any with cervical cancer - why screening is so important

Tests and Diagnosis

Pap smear

HPV DNA test

while its said that most people have been infected with at least one of the hundreds of strains, only certain strains. the HPV DNA test checks for cancer causing strains


Cone Biopsy

other tests such as CT, MRI, PET may be needed depending on tghe condition


contraception - cervical diagphragm or cervical cap (where the sponge was once placed)

progesterone only pills thicken mucous to help prevent passage of sperm

tests of cervical mucous to determine when the best time is to become pregnant

Billings method

HPV vaccine

cerclage for incompetent

antibiotics for stds

treatment for dysplasia - cryo, laser, leep

surge - hysterectomy

may need chemo, radiation, other treatments

Caring For Your Cervix

practice safe sex

regular Pap smears

HPV vaccine - FDA now increased approval for women up to the age of 45

The incidence and death rate from cervical cancer have dropped markedly since the adoption of regular Pap smears, but it remains the fourth leading cause of cancer-related deaths in women worldwide.

Regular Pap smears can identify most abnormal and precancerous changes well before cancer develops


Regular Pap smear

artificial intelligence may make a difference! new study, iphone images!

A Word From Verywell

Cervical cancer screening guidelines that were updated by the American Congress of Obstetricians and Gynecologists (ACOG) in February 2016 suggest:

  • Women should have their first Pap smear at age 21. (The old guidelines recommended that women have their first Pap three years after becoming sexually active or at age 21—whichever came first.)
  • Women aged 21–29 years should have a Pap test alone every 3 years. HPV testing is not recommended.
  • Women aged 30–65 years should have a Pap test and an HPV test (co-testing) every 5 years (preferred). It also is acceptable to have a Pap test alone every 3 years.
  • Women age 65 or older should 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 in a row within the past 10 years, with the most recent test performed within the past 5 years.
  • 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, cervical cells can still be present at the top of the vagina. If you have a history of cervical cancer or cervical cell changes, you should continue to have screenings for 20 years after the time of your surgery. 
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    Article Sources

    • Kumar, V., Abbas, K., and J. Aster. Robbins and Cotran Pathologic Basis of Disease. Philadelphia: Elsevier-Saunders, 2015. Print.