Last updated: Jun 03, 2016

Let’s be honest: How much do you really know about your cervix?

“A lot of women don’t even know what it is,” says Michelle Berlin, MD, a professor of OB/GYN and co-director of the Oregon Health & Science University’s Center for Women's Health. “They don’t know,” she explains, “because they don’t see it.”

So, here are the 10 basics all women ought to know:

It's located between the uterus and vagina

Your cervix, which is about 2 inches long, sits at the bottom of your uterus and at the top of the vagina.

It plays a big role in reproduction

The cervix ferries sperm into uterus. If you conceive, the cervix holds the fetus in the uterus until it’s time to give birth, when uterine contractions cause it to widen to about 10 centimeters (roughly 4 inches) so the baby can pass through the vagina.

It’s remarkably resilient

In pregnancy, a thinning, widening cervix signals that labor has begun. Even after stretching 10 centimeters to allow a baby’s passage, the cervix springs back and heals nicely, Dr. Berlin notes.

RELATED: 20 Facts Every Woman Must Know About Her Vagina

It's where your period is released

You know that when you don't get pregnant, you menstruate. What you may not realize is that it's the cervix that allows the blood to leave your body.  

It tries to protect your fertility

Your cervix is the first wall of defense against sexually transmitted diseases that could lead to infertility. “You can’t get to the uterus without going through the cervix,” says Nicole Scott, MD, a board-certified OB-GYN at Indiana University Health in Indianapolis.

The human papillomavirus (HPV) causes most cervical cancers

HPV is the most common sexually transmitted infection in the United States. The Centers for Disease Control and Prevention (CDC) says an estimated 80% of women will be infected before they are 50. The virus can alter the cells of the cervix and, over many years, these changes can lead to cancer if not detected and treated.

RELATED: 17 Things You Should Know About HPV

Cervical cancer is highly preventable

With regular screening and early treatment, cervical cancer is the most treatable female cancer. All women, beginning at age 21, should have a Pap test to detect the presence of abnormal cells. For women over 30, an HPV test may be given, too. Its purpose is to screen for specific types of HPV that can lead to cervical cancer.

The HPV vaccine is highly protective

The HPV vaccine doesn’t treat existing disease, but it can protect against the types of HPV that cause cervical cancer. It’s recommended for ages 9 to 26. The vaccine works best in the body when it’s given in youth and before young people are exposed to the virus, Dr. Berlin explained.

Other infections can attack the cervix, too

In women, gonorrhea and chlamydia commonly affect the cervix. If left untreated, these infections can lead to pelvic inflammatory disease, a condition that can lead to serious fertility complications.

Your cervix hates cigarettes

Women who smoke are twice as likely as non-smokers to get cervical cancer, according to the American Cancer Society. Smoking makes the immune system less effective in fighting against HPV infections, says Dr. Scott. What's more, tobacco byproducts have been found in the cervical mucus of women who light up, and researchers believe that these substances may damage the DNA of cervical cells, contributing to the development of cervical cancer.