At any rate, now we are all adults, and this calls for a refresher. Some of you are old pros. Some have just learned that the vagina (where menstrual flow and babies come from, also the organ/muscle that is utilized in sexual intercourse) is different from the urethra (the hole between the vagina and the clitoris, where urine exits the body). That's all okay. After all, this doesn't often come up in polite conversation. Especially the part about how the clitoris is analogous to the head of a man's penis and is responsible for 70% of women's orgasms.
But moving right along...
One of my services is to explain to young women about their bodies and how they grow and change as we get older. It's a heavy subject, so I try to make it fun and lively, which is why I bring the pear...and the walnuts.
Picture an upside-down pear. That little, green fruit filled with succulent juices. Yum. This is your uterus. Or at least the approximate size and shape of your uterus. Now the uterus is rounded on the top and narrow on the bottom, just like the pear. That narrow part of the pear is much like your cervix. About where the stem on the pear would be is where one would find the cervical os. It's pronounced "ahsss," which is sort of how a British English speaker might pronounce "ass" if they weren't so busy saying "arse" all the time.
Ug, I'm reverting to 6th grade humor again. :)
To continue, at the "top" of the upside-down pear (or the widest part of the pear) we would find the fallopian tubes. One on each side and both completely connected to the uterus. The fallopian tubes, by the way, are about the width of a strand of hair.
So now you've got your upside-down pear with two strands of hair sticking out of it. Good. We're making progress. :)
Now here is where the walnuts come in. You see, the walnuts are the ovaries. Well at least they are about the same size and shape as your ovaries. And you have two of those also. One on each side, slightly below where the hair ends. Yes, unlike what most textbooks seem to demonstrate, the fallopian tubes are NOT also connected to your ovaries. Only the uterus. Those ovaries are filled with millions of tiny eggs. These eggs were in your body before you were even born. All little baby girls (barring unusual circumstance) are born with all of their eggs already inside their ovaries. Each egg is about the size of a grain of sand.
So now that we've got the reproductive system down, how do we end up with a period?
Since women's body rhythm's are cycular, it's impossible to have a beginning and end, since the cycle continually perpetuates itself, but for our purposes (and because we need to start the explanation) let's begin with day 1 of the cycle, which is the first day of bright, red menstrual flow. Notice I am not using the term "bleeding." Bleeding is just a part of the menstrual flow, which also involves tissue and other components of the endometrium. So we begin bleeding with a bright, red menstrual flow (not spotting). A woman might even notice feeling a bit colder around this time. This is because her temperature is dropping. It's a slight drop, but a drop nonetheless. And it will not come back up into the same higher range until after the woman has ovulated. This is very important when trying to understand our fertility and why you may have heard about women taking their temperatures when trying to conceive (TTC).
Once the menstrual flow begins (and even in the few days leading up to this event), the pituitary gland (located in the base of the brain...that's quite a distance from the vagina!) has begun secreting a hormone called FSH (follicle stimulating hormone). This hormone is...you guessed it...causing the eggs in your ovaries to become mature. This process of maturity actually causes a cyst to form within the ovary and then a race begins. The many cysts, or follicles, begin to grow until at least one begins to actually press out of the ovary, so that, in western medicine, it is visible on an ultrasound. This is usually the point where a doctor trained in the western medical model will begin to speak about "cysts on the ovaries" or "poly cystic ovarian syndrome/disease" (PCOS). But, having follicles on the ovaries is the keynote sign of a normal, healthy, functioning reproductive system. At least at this point in the cycle. At any rate, as these cyst/follicles are growing right up and out of the ovary, the body is also releasing another hormone called LH (luteinizing hormone) which further assists in "ripening" the follicles.
Now this is the cool part that I never really "got" until I had deeply studied the reproductive system, but both the estrogen and, later, the progesterone in a woman's cycle actually comes from these follicles, albeit at different stages of their "lifetime."
It is when these follicles are maturing that they begin secreting estrogen into the woman's body. At this point, a whole host of biofeedback occurrences take place, which are not completely understood by modern science, but basically, one follicle begins to become dominate while the other ripening follicles begin to recede and deteriorate back within the ovary. Sometimes more than one follicle continues to develop and this would cause the ovulation of multiple eggs, potentially leading to fraternal twins, triplets, or more, should the woman become pregnant. Of course, this is also what is being done to the body when Clomid and injectibles are being used to hyper-stimulate the ovaries.
The estrogen released by these follicles are causing our fertility signs to materialize. (These are the signs I will teach you how to read at our first appointment, or you can get a head start by reading Taking Charge of Your Fertility, 10th Anniversary Edition: The Definitive Guide to Natural Birth Control, Pregnancy Achievement, and Reproductive Health ) It is also causing the lining of the inside of the uterus to grow, so that it is blood rich and ready to support and nourish a forthcoming embryo.
Eventually, a follicle becomes fully grown and the body reaches an "estrogen threshold." At this point the pituitary gland signals a surge of first LH and then FSH, which causes the body to ovulate.
Now what is ovulation? Well, picture a volcano erupting. That is exactly what it looks like. The egg just shoots right out of the ovarian wall right out of it's fluid filled cyst/follicle. This fluid now becomes the corpus luteum and begins producing progesterone! It is here that the temperatures of the woman rise. Some actually noticeably feel warmer at this time in their cycle.
But wait! We now have an egg floating around freely in the pelvic cavity. Thankfully the hairs on the end of the fallopian tubes are doing their job of drawing the egg into the tubes where it must already have a sperm waiting in the outer 1/3rd of the tube to fertilize it, if we are to have a live, healthy baby. (I, personally, think this is the biggest miracle of the entire process.)
Sperm, meet egg. Egg, meet sperm. Sperm penetrates the egg, and the resulting embryo begins to divide as it continues in it's travels down the fallopian tube and into the uterus where the cushy, plush uterine lining (aka, the endometrium) is waiting to provide it's home. Embryo enters uterus and burrows itself into the endometrium and begins to secrete HCG (human chorionic gonadotropin) causing the corpus luteum to extend their lives of progesterone production. Or there is no growing baby. In which case the natural life of the corpus luteum comes to an end, signaling the all time cycular low of both estrogen and progesterone and causing the woman to have a "period."
This is where the endometrium sheds off of the walls of the interior uterus and slides down into the cervix and through the cervical os, which is the little hole leading from the cervix into the vagina. Down the endometrium goes, through the vagina and exiting the body in the form of a menstrual flow.
And now we can move on to the first place where we poison our bodies and inadvertently diminish our fertility: Feminine menstrual products.