Now this is our kind of sex ed.

By Anthea Levi
April 04, 2018

When it comes to sexual health, we'd like to think we've covered it all—from male and female anatomy to sex, orgasms, and fertility. And we've definitely delved into our fair share of questionable vagina trends, such as whether inserting garlic into the vagina can treat a yeast infection and if squatting over steaming coffee really will induce labor. (No and no, for the record.)

So when we came across The Wonder Down Under ($21, amazon.com), we were surprised to learn that there’s actually a lot more we haven't covered concerning sex and sexual health. In fact, we learned so much from coauthors and sex educators Nina Brochmann, MD, and Ellen Stokken Dahl, we knew we had to share. Below, 10 fascinating tidbits you probably didn’t know about your wonder down under. 

RELATED: 20 Facts Every Woman Must Know About Her Vagina

There’s more to the clitoris than meets the eye

Most people think that the clitoris is a small pleasure zone tucked inside the vulva. Turns out that what you see is only the tip of the iceberg, so to speak. The clitoris extends well into the pelvis—and it develops from the same tissue as the penis.

“Up until about the twelfth week in the uterus, the genital tracts of male and female embryos are exactly alike, dominated by a kind of mini-penis (or giga-clitoris!) known as the genital tubercle,” write Brochmann and Stokken Dahl. “It has the potential to develop into either a female or male sexual organ. Since the penis and clitoris both develop from the same basic structure, the two organs share many similarities of form and function.”

One difference: The head of the clitoris has 50 times the concentration of nerve endings as does the head of a penis. No wonder even a little too much pressure there can quickly go from pleasurable to painful.

Pubic hair can boost your sexual pleasure

Going bare down there might make you feel sexier. But keeping some pubic hair comes with a surprising benefit: more pleasure during sex. Hair around the vagina helps "to heighten our sexual sensitivity,” the authors state. “If your partner strokes you lightly over your pubic hair, the bending of the hairs will send a signal to the follicles, which will pass the message on to your nervous system.” Without bush, you might be cheating yourself out of sexual sensation.

RELATED: Is Bush Really Back? Most Women Are Still Going Bare Down There, Study Finds

If you are shaving down below, cheaper razors are better

Yep, you read that right. Apparently single-blade razors are better. Why? Pricier ones that come with multiple blades are more likely to cause ingrown hairs, since each additional blade cuts hair farther beneath the surface of the skin. “What’s more, the high price means that a lot of people avoid changing blades as often as they should, so that the blades become blunt and covered in bacteria,” according to Brochmann and Stokken Dahl. 

Discharge keeps things clean

“The purpose of discharge is to keep the vagina clean and to flush out unwelcome guests such as fungi and bacteria, as well as dead cells from the surface of the mucous membrane,” write the authors. This whitish or clear fluid (depending on where you are in your cycle) also contains a decent amount of good bacteria, like lactobacilli, to help ward off infections.

That’s not all though. Discharge helps lubricate the mucous membranes in the vagina. Without it, we’d be way more likely to experience tears, sores, painful sex, and STIs. Never thought we'd be saying this, but discharge is your BFF.

RELATED: This Video Shows How mUch Vaginal Discharge is Normal (It’s Way More Than You Think)

You have your period for 6.5 years straight

Let’s break it down: Say you bleed once a month for five days. That’s 60 days of bleeding every year. If you have a period for 40 years, that’s 2,400 days of menstruation, which equals about 6.5 years over the course of your life. Mind. Blown.

Yes, it's safe to do headstands during your period

Avid yogis have probably heard yoga instructors advise against inversions (think: handstands, headstands) while menstruating. Yet there’s actually no reason to avoid the challenging poses during shark week. “Periods are the expulsion of the endometrium. You get no more and no less endometrial growth no matter what you do,” the authors tell us. So feel free to do a headstand (or swim, or have sex, or run a marathon!) at that time of the month.

Having an orgasm might kickstart your period

Have you ever had sex . . . and then immediately started your flow? You’re not alone. While experts aren’t totally sure why this happens, they do have a few theories. One is the “cramps theory,” which holds that the same uterine contractions responsible for pushing out period blood also trigger contractions during orgasm. So if you’re having sex right before your period is set to start, the muscle spasms that take place when you climax may help release menstrual blood.

RELATED: The Best (and Worst) Exercises for Pregnant Women

Most women don't truly have PMS

We may call our pre-period mood swings and chocolate cravings PMS, but true premenstrual syndrome is a condition that causes symptoms so severe, they prevent women from engaging in everyday life. They also tend to occur almost every month, not just once in a while.

“Moreover, the symptoms must start and stop at the times typical for PMS: They must start in the premenstrual phase and stop when your period arrives,” write the authors. “Around 20 to 30 percent of all women have symptoms that qualify as mild or moderate PMS.” 

Sex drives aren't really a thing

It’s a myth that we are born with a sex drive. “Drives are like instincts that help keep us alive,” explain the authors. “They are what cause thirst, hunger, and tiredness among others.” So although life would be less interesting, we don’t actually need to have sex in order to survive.

Brochmann and Stokken Dahl say we should instead think of sexual desire as a reward. “The system only works as long as sex serves as a reward for the brain. In other words, we’re not born with a sexual appetite, we become sexually desirous.”

RELATED: We Asked 8 Women What an Orgasm Feels Like to Them—Here’s What They Told Us

Working out before sex can make an orgasm more likely

Here’s a good reason to get sweaty before you get sexy. “Exercise, especially right before sex, makes it easier for you to get aroused and increases many people’s capacity to reach orgasm,” write Brochmann and Stokken Dahl. BRB, heading out for an evening jog. . . .