Period Basics

How Does A Menstrual Cycle work?

Simone Giertz

How Does A Menstrual Cycle work?

Check out Simone Giertz’s menstruation machine as she helps young women demystify the amazing process their body goes through.

Simone Giertz builds the menstruation machine to explain menstrual cycle. In collaboration with the Kotex She Can Initiative, Simone helps young women demystify the amazing process their body goes through in her trademark style blending education and humor.

About Simone Giertz

Simone Giertz is a Swedish inventor, YouTuber and robotics enthusiast. She is world-renowned for her useless machines and has risen to the very top of the field, mainly because the field is very tiny and not of great interest to anyone else. She currently has 2.46M subscribers on YouTube and her popularity continues to grow every day with her machine builds.

Video Transcript

The thing I like most about uteruses is…no it’s not uteruses. What's the plural of uterus? Uteri?

My name is Simone Giertz, and today we’re going to talk about the menstrual cycle in collaboration with the Kotex She Can Initiative.

So. The thing I like the most about the uterus is that it’s the only organ in the body that has an agenda.

Like … your lungs are breathing. The heart is pumping blood. Your kidneys are making pee. And meanwhile, the uterus is like “Hey. You. Me. Let’s make some Babies”

And I’m like: “maybe I don’t want to have a baby right now?”

And the uterus is like: “Well, I’ve been working on this all month, and the groundwork has all been setalready and turns out *checks notepad* I don’t care what you want”


It’s an ovary headband I made. I made it.

The groundwork in this case is also what’s known as the menstrual cycle.

And it’s this really complex process and it can be difficult to understand, and whenever I struggle with something, my solution is always to build a machine.

So. Here we are… It’s a uterus!

Or, it’s an anatomical-adjacent uterus at least! We have the ovaries, the fallopian tubes, the uterus, the cervix, the vagina. And I also added some cogwheels for extra flair.

You don’t actually have cogwheels in your body. Unless you’ve eaten some, which I can’t recommend. Because they don’t taste very good.

Ok, so… The way I think about the menstrual cycle, is like a really elaborate dating program.

We have the contenders, also known as thousands of eggs that live in your ovaries. You’re actually born then it’s just steady downhill from there.

So, all these eggs are just hanging out in the ovaries, hoping one day they’ll get to meet some sperm.

I don’t want to be the one that tells them, but most of them won’t actually get a chance. Only about 300 of your eggs will actually get ovulated, and the rest will hang out in the ovaries... until they die of old age and possibly boredom.

So the ovaries take turns releasing eggs. And that's what’s known as ovulation… should we ovulate? I mean not we.. but the machine, there’s a remote.

Ok, ovulate!



Ok, this is actually something that kind of happens in the body as well. The connection between the fallopian tubes and the ovaries are not a perfect fit. So some eggs will just wander out into the abdomen and find their own adventures until they also die and get reabsorbed into the body because it’s a really harsh life being an egg…. been there, done that.

Ohhh yeah! Innovation for ovulation!

Each fallopian tube is about 4-5 inches long, and it takes 6-12 days for the egg to travel through it. There are a lot of things that are impressive about this process. The speed at which the egg travels, is not one of them.

And it’s during this journey, there’s a 12-24 hour window where the egg finally has its chance to meet the sperm of its dreams. I was today years old when I learned that fertilization happens not in the uterus, but in the fallopian tube! It’s like it’s in the hallway on the way to the uterus bedroom!

Doesn’t mean the uterus isn’t hard at work.

It’s producing really stringy discharge that makes it easier for sperm to climb, it’s like throwing ladders down the vagina, being like “hey, there’s a new egg in town, come up here!”

The lining of the uterus is also growing thicker, and it’s essentially like decorating an entire baby room, just in case a fertilized egg comes around.

But most of the time, no sperm comes by, and the egg contestant gets stood up in the fallopian tube, and it finishes its travel alone... and out the door.

And since no pregnancy happened, the uterus starts shedding all that extra lining.

And that is what getting your period is! It’s the uterus shedding all the perishable items that it doesn’t need since there’s no baby growing.

Generally, we bleed about 120 – 200 ml per period, which might not sound like a lot, but it can sure feel like it.

And some people experience discomfort during different parts of their menstrual cycle like achy boobs, bloating, cramps and mood swings. And some people have barely any symptoms at all.

The complete menstrual cycle is between 21 to 35 days long, and half of the human population spend a big part of their lives with this very elaborate egg-sperm dating program playing out in their bodies.

None of us would be around if it wasn’t for the menstrual cycle, like this is a big reason for why we’re alive. But does it get credit for that though? I don’t think so?

Often periods get treated as something dirty or embarrassing and we don’t really talk about it, even though it can have a big impact on our lives.

So, if you ever feel down because you're having your period … remember that you can bleed for five days without dying. And if that’s not cool, then I don’t know what is.

… It’s still going. It’ll take a couple of days actually.

This Menstrual Machine was created in collaboration with The Kotex SheCan Initiative, an organization that champions women’s progress by fighting period stigmas and the barriers they cause.

Simone: Do we really need to do this every month though?

Uterus: Yes.

Simone: Why?

Uterus: Because I want to.

Simone: Ok what if I can pee out the period blood instead?

Uterus: No ...No. This system is a masterpiece. Also, that reminds me, I gotta run because we are scheduled to release another egg again in two days. And I can tell you, this one is going to be a good one. Okay, ciao!!

Kimberly-Clark makes no warranties or representations regarding the completeness or accuracy of the information. This information should be used only as a guide and should not be relied upon as a substitute for professional medical or other health professional advice.