female cycle 101

For a long time, I interpreted the female cycle like this: I have nothing for 3 weeks and then I bleed in pain for a maximum of one. Sadly, this is what most people know about the female cycle.

But the longer I researched about it, the more I realized how complex and multi-layered the female cycle is. All processes are controlled by hormones. The uterus doesn't do anything on its own - it responds completely to the hormones. But let’s start from the beginning:

It all starts in the hypothalamus (a part of the brain). This is where the gonadotropin-releasing hormone (GnRH) is produced and released. This happens pulsatile, i.e. GnRH is released to the pituitary gland every 90 minutes or so. In times of hunger, great stress or war, this release is stopped because the body realizes that pregnancy would not be safe in this environment. The whole thing is quite smart!

However, if this happens regularly, the pituitary gland produces follicle-stimulating hormone (FSH). And that's exactly what FSH does: it stimulates the follicles in the ovaries. But what are follicles actually? Follicles are not egg cells. The follicle is a collection of tissue, mainly consisting of granulosa cells and fluid, which shelters the egg cell and allows it to mature. You can think of the follicle as that bubble wrap that protects fragile objects. The kind you like to pop between your fingers ;-).

As soon as the follicles are stimulated, the granulosa cells now produce the hormone estrogen. THE female sex hormone. The pituitary gland notices this and takes some of the pressure off, i.e. it minimizes the release of FSH. The ever-growing follicle releases more and more estrogen to build up the uterine wall for a possible pregnancy. As soon as the estrogen has reached its peak, the pituitary gland kicks in again and releases the luteinizing hormone (LH). This triggers ovulation.

Ovulation is nothing more than the egg cell jumping/bursting out of the follicle. 24 hours later, the egg is picked up by the "funnel" of the fallopian tube and guided through the fallopian tube. There it hopes to meet sperm in order to be fertilized. If this does not happen, the egg cell dies.

But what happens to the remaining empty follicle in the ovary? This then transforms into the corpus luteum. The corpus luteum now releases the gestagen hormone. One of the most important representatives of gestagen is the hormone progesterone. Progesterone ensures that the lining of the uterus continues to develop in such a way that the egg cell wants to settle comfortably in the uterus.

However, if the egg does not meet any sperm, it dies and all the building up of the cosy uterine lining is "wasted work". Around 9 days after ovulation, the corpus luteum (formerly the empty follicle wall) transforms into scar tissue and releases less and less progesterone. The body therefore realizes that it does not need the cozy lining of the uterus and sheds it - menstruation begins and thus, the first day of the female cycle starts again.

the phases of the female cycle

I find this graphic a very good one. It's more in detail and explains the whole cycle in pictures:

https://stock.adobe.com/pt/images/female-sexual-cycle-vector-illustration-graphic-diagram-with-menstruation-and-ovulation-chart-and-uterus/193006260

So, quite a lot happens in a woman's cycle, which can be between 23-35 days long. A man's cycle is much less characterized by the ups and downs of hormones. It happens in one day. For men, for example, the sex hormone testosterone is at its highest in the morning. This might explain the so-called morning wood ;-).

This knowledge about the female cycle is essential for everyone. Not only because it explains the reproduction of humankind, but also because women really go through a lot during these phases. The drop in hormones, or rather the interaction between them, influences performance (at work and in sport), mood, the risk of injury, even the thickness of the blood and so much more. If we know this, we can better understand, deal with and support it. So, let’s all learn more about the female cycle.