This post is a quick and simple Girlybits 101, using very small words and no gross or scary diagrams so that people can know a little bit more about their bodies without sending themselves into a hormonal frenzy. The way women experience their cycles is very heavily influenced by their diet, their activity level, their relative amount of stress, their environment, their age, their reproductive status, how much muscle they have, how much fat they have, what types of activities they perform, where they live, etc. etc. etc. In short, a major theme of female reproductive physiology is that nothing is ever the same, not between women and not even within the same woman over time.
And now, I present to you this Totally Easy And Not At All Gross Explanation of what happens with your girlybits each month.
(1) You have ovaries, which are a bit like testicles but on the inside. You probably know that ovaries make eggs, but they also make and release endocrines (more commonly known as hormones), which you can think of as messengers. Like letters in the mail. Or text messages, or whatever.
(2) Every month, one of your eggs begins to mature. Your egg has a comfy little home inside the ovary that provides it all the things a growing egg needs. However, the ovary knows that one day the egg will have to leave the ovary and venture out into the fallopian tubes, where it might possibly meet a charming young sperm and settle down. The ovary wants to make sure that life is easy for the egg when it leaves, so the ovary makes estrogen (an endocrine).
(3) Estrogen travels through the blood and goes all sorts of places doing all sorts of things. One of these jobs is to build a future home for the egg in your uterus.
(4) After 14 days or so, the ovary has done all it can do to nurture the egg. Now the egg has to leave the nest and strike out solo. However, this story has a twist. If the egg doesn’t meet a handsome sperm and fall in love within about three days, it will DIE!!! (No pressure.)
(5) After the egg has left the ovary to go look for Mr. Right, the ovary continues to make estrogen and also progesterone, which is another endocrine that has a similar job to assist in building the egg’s dream home.
(6) At this point, one of two things can happen. The egg can meet Mr. Dreamy Sperm at the Fallopian Club, fuse with him, and move into her Uterine Dream Home, or she will die forever alone.
(7) If the egg dies, the ovary eventually stops releasing estrogen and progesterone (it takes a few days because, uhh, the ovary doesn’t have e-mail so it has to wait to get the news of the death through the mail), and a wrecking crew comes by and demolishes the dream home. If the egg fused with Mr. Spermy and becomes a zygote, she starts secreting her own endocrines to communicate with the ovary, telling the ovary what a nice sperm she met and that they’re very happy in their new home. The ovary continues to release estrogen and progesterone so that they have a pleasant stay for 9 months, after which a baby magically appears.
Most forms of hormonal birth control interrupt this cycle so that step 4 never happens. The egg never leaves the ovary, so it never has to choose between marriage or death. If the egg has already moved out, birth control stops the egg and sperm (collectively called a zygote after they fuse) from moving into the dream home. Unfortunately, birth control can’t do anything if the egg and sperm have already moved in.
Michelle from C6H12O6
Image source: personal.psu.edu