The Female Reproductive Organs & the Endocrine Glands that Make Them Function

This excerpt from The Cycle was written by Groove’s founder Jennifer Aldoretta

Because your reproductive organs are oh-so-neatly tucked away, revealing their awesomeness requires taking a closer look. The battle to liberate the female body from social stigmas surrounding menstruation begins with an improvement in menstrual education, and achieving this goal starts with knowledge of female reproductive anatomy.

The purpose of this section is to do a little exploring to learn all about lady parts.

The Female Reproductive Organs

While looking at a diagram of the female reproductive system might be interesting, it tells us nothing about the purpose of each of these organs. We can’t simply glance at a car’s engine and immediately know how each part contributes to the functioning of the engine as a whole.

The same concept applies here, so I’ll give a simple description of each of the parts labeled in the diagram to give you an idea of just how amazing that female engine really is!

The Ovaries

The ovaries are small, almond-sized pouches that, together, house about a million tiny follicles. Each of these follicles houses a single immature egg, also known as an oocyte.

A human female is born with follicles that will last an entire reproductive lifetime, unlike a male, who produces sperm continually. Over the course of the menstrual cycle, a few of these follicles develop so that they may have the chance to release their egg, while all other follicles remain dormant, or inactive.

These few follicles that develop each cycle are responsible for the production of the hormones called estrogen and progesterone, which are key players in the menstrual cycle.

Only a fraction of your ovarian follicles will ever ovulate, and the ones that do endure quite the journey! It takes approximately one year for a follicle to develop from a primordial (or immature) follicle to a follicle that is ready to ovulate [22]. The not-so-lucky follicles that develop but never get a chance to ovulate (or release their mature egg) are instead reabsorbed by the body in a process called atresia.

The Uterus

The uterus is the female reproductive organ you’re probably the most familiar with, as this small, pear-shaped organ plays an important, well-known role. During every cycle, the lining of the uterus swells with blood in hopes of providing nutrients to a fertilized egg, or an embryo. If an embryo does imbed itself in the uterine lining, the uterus ensures the developing fetus is warm and cuddly and provides it with nutrients before it is born. If an embryo does not imbed in the uterine lining — and, therefore, a pregnancy does not occur — the lining is shed through the process of menstruation.

The Vagina

The vagina is the pathway between the uterus and the vaginal opening (which is part of the external female genitalia, or the vulva). During menstruation, the endometrium (or menstrual fluid) flows through the opening of the cervix (or the os), through the vagina, and out the vaginal opening. Aside from its more obvious purposes, the vagina maintains an acidic environment to prevent harmful bacteria from causing an infection. This prevents vaginal and yeast infections and also helps prevent potentially harmful bacteria from reaching a developing fetus during pregnancy. This acidic environment keeps the vagina clean — no lady-part irrigation necessary.

The Cervix

The cervix is often overlooked as a vital part of the female anatomy. Many people — and I used to be one of them — only know the cervix as that thing that dilates during childbirth. But, oh, how misguided this is! The cervix (which connects the uterus and the vagina) arguably plays the most important role of all in the process of getting pregnant, and, conversely, in the process of practicing natural birth control using the sympto-thermal method of fertility awareness (STM).

The cervix produces fluid — called cervical fluid or cervical mucus — very similar in makeup to seminal fluid, which aids sperm survival and motility. The acidic environment maintained by the vagina helps prevent infection by keeping bad bacteria at bay, but it also happens to be extremely inhospitable to sperm. Without cervical fluid (cervical mucus), it would be highly unlikely (and perhaps impossible) for a pregnancy to naturally occur! Luckily, for those of us wanting to practice natural birth control, cervical fluid (cervical mucus) is typically only produced around the time of ovulation.

So monitoring this cervical mucus on a daily basis tells us, with a high degree of accuracy, when we need not worry about unprotected intercourse resulting in an unwanted pregnancy. Knowing what to look for is key, so don’t even think about trying to use the sympto-thermal method as natural birth control or to get pregnant faster without first reading about how to practice the rules of the sympto-thermal method, how to check your fertility signs, and important information about the effectiveness of the sympto-thermal method as natural birth control.

The Fallopian Tubes

I like to think of the fallopian tubes as the arms of the female reproductive system. The end of each fallopian tube is lined with finger-like structures known as fimbriae, and the inside of the fallopian tubes are lined with tiny hair-like structures called cilia. The purpose of the fimbriae is to scoop the newly ovulated egg, or ovum, into the fallopian tube (hence the arm analogy!). Then, the cilia take charge and begin directing the ovum towards the uterus by moving in a wave-like motion.

It is a common misconception that fertilization takes place in the uterus, when in fact it typically occurs in one of the two fallopian tubes. If the ovum is fertilized, the embryo (or fertilized egg) moves into the uterus for implantation. If fertilization does not occur, atresia (or reabsorption) of the ovum also occurs in the fallopian tube.

The Pituitary Gland and Hypothalamus

You might be asking yourself why I’m continuing with all the anatomy talk after I just made you stare at a vagina drawing. Our knowledge of the female reproductive system is far from complete if we exclude the roles of the pituitary gland and the hypothalamus. They are, after all, the brains behind the entire operation. It is perfectly suiting, then, that they are both located in the brain!

The body’s endocrine system — of which the hypothalamus and pituitary gland are included — is an awesomely powerful system. I’ll discuss the exact method by which these structures carry out their functions below, but what you should take away from this spiel is the importance held by such small-statured parts of the body. Without these two small structures, the menstrual cycle would cease to be.

The hypothalamus and its sidekick, the pituitary gland, are continuously communicating with your reproductive system. These structures are a great little tag-team that are responsible for many of the processes necessary for homeostasis, or the body’s ability to maintain a stable internal environment. Without them, not only would menstruation cease to be, but so would we.

The Pituitary Gland

The pea-sized pituitary gland is located at the base of the brain just above the brain stem. It helps control processes such as growth, thyroid function, body temperature regulation, and sex organ function. Under the direction of the hypothalamus, the pituitary gland releases two of the hormones directly responsible for the menstrual cycle: luteinizing hormone (LH) and follicle stimulating hormone (FSH).

In another section, I’ll discuss the roles of LH and FSH in the menstrual cycle.

The Hypothalamus

The hypothalamus is a small portion of the brain located directly above the pituitary gland. The hypothalamus is responsible for controlling some very important functions including hunger, thirst, sleep, body temperature, and hormonal and behavioral circadian rhythms. However, our primary focus will be on its role in the female reproductive system.

The hypothalamus produces a hormone called gonadotropin-releasing hormone (GnRH) in response to hormonal signals it receives from the ovaries. This GnRH triggers the pituitary gland to produce LH and FSH, and lets it know how much of each to release into the bloodstream.

So you might say that the hypothalamus and GnRH are the pilot and copilot of the menstrual cycle plane: they keep operations running smoothly, but when the ovaries (or air traffic controllers in this awesomely bad analogy) chime in, the hypothalamus and GnRH adjust to keep the menstrual cycle (or the plane) on course.

Not so bad, right? Next up, we’ll focus on how female sex hormones work together to produce the menstrual cycle. I personally did not have an understanding of this important information until I was well into adulthood. Unfortunately, this isn’t uncommon; many people find they have a huge knowledge gap when it comes to specifics regarding female sex hormones and reproduction. Now is the perfect time to change that.

Hormones & the Menstrual Cycle >>