For the longest time, my only knowledge of my reproductive system was the basics I learnt in biology class and what my mom taught me about my body when I started menstruating, which was just a fearful call to abstain from sex.
Not even when I had my children did I know my body so well. It was just a matter of being favoured in my fertility. However, the female body has become one of the few things I know so much about, thanks to The Fertile Chick, and even at that, there is still so much to learn.
While I already know the theory that states that women are born with all the eggs they will ever have in their lives, unlike the male folks who are able to regenerate their sperm cells ever so often, I was definitely stunned when a study came out stating that it was possible for women to actually regenerate eggs in their lifetime, besides those they were born with.
Hmmm!!! It got my attention, but something else did too. The workings of the female eggs are not often discussed. We know about sperm, it’s count, motility, and morphology, but not much else is known about the female eggs, which are actually called oocytes, apart from the fact that many are released every month, upon menarche, and a few other vague details.
Today, we will focus especially on the oocytes, and all the things women and everyone interested in the female reproductive system should know. This is what my research showed me:
They are made early in the female body:
Based on the theory that women are born with all the eggs they will ever need in their lives, it is believed that a female embryo starts making eggs at just 9 weeks of gestation
By the time the baby is five months in utero, a female foetus is speculated to have made upward of 7 million oocytes! Now, that’s a whole lot of work for a not fully formed baby body to be doing.
At birth, it is said that the vast majority of these immature egg cells would have died, but millions more would have replaced them, and that is what she will use later in life.
Eggs are rare, thus precious:
There is a general belief that the rarity of certain things makes humans value them more. That is exactly the case with the female egg; it is a truly rare piece.
On average, a woman ovulates a mere 400 to 500 eggs in her lifetime. That number automatically makes eggs far rarer than sperm cells. Clearly, more sperm cells are released during a single ejaculation than a woman produces eggs in her entire lifetime.
Perhaps, that’s one reason why eggs are worth so much more than sperm.
Women may actually be making more eggs throughout their lifetime after all:
Back to the latest hypothesis (as it is still being tested) that women may actually be making eggs throughout their lifetime, more like the male folks, scientists discovered a new type of stem-cell in the human ovary that may point to the possibility of new eggs continually being formed throughout a woman’s reproductive years.
Further research will be able to confirm this new theory though, as the study was carried out on mice, not humans.
Eggs take a while to mature:
Seeing that it is scarce, it makes sense that eggs would take a while to grow to a matured state, before they can be released.
If still working with the long term theory that women have finite number of eggs, then most eggs are present within the ovary in an immature state from the moment a girl child sees her first period; menarche.
Through her life, eggs will be released, based on how mature they are. Some eggs will lie dormant for years, or even decades, before they begin to mature, while others will degenerate and never develop.
Scientists have discovered that for eggs to be ready for ovulation, the body actually starts priming them about 150 days before they would be released from the ovary.
At the beginning of any given cycle, there are generally about 12 eggs which would have started to grow, and as ovulation nears, preference is given to one of those eggs, as it receives the final push to maturity and is then released from the ovary.
150 days? The female body produces magic.
The lifetime of a mature egg is actually very short:
Even though it took the egg a whopping 150 days to get to ovulation, it’s lifespan after that is very short. Once the egg has matured and is released from the ovary during ovulation, it goes into the fallopian tube where it lives for 12 to 24 hours.
Conception can happen if the sperm is already in the fallopian tubes when the egg is released, or if a woman has sex while the egg is alive, causing sperm to swim up through the uterus and into the fallopian tube.
Sperm can reach the egg in as little as 30 minutes. Unlike the egg, sperm can stay alive inside a woman’s uterus and fallopian tubes anywhere from 1 to 5 days. This means that sex up to 5 days prior to ovulation can actually result in pregnancy!
The lifespan of the sperm is dependent on the sperm’s health, but also on the woman’s cervical fluid, which can nourish the sperm while it waits for madam eggy.
The female egg is the biggest cell in the body:
Egg cells are among the largest cells of the human body. To give you an idea of just how big they are, take note that most of your body cells cannot be seen with the naked eye. You would have to use a microscope to be able to see a sperm cell or a liver cell, for instance.
An egg cell, however, is visible to the naked eye, at 0.12 mm in length, that is like the size of a strand of your hair. It is, however, definitely visible and the biggest in the human body.
The egg is a picky lady and also loyal:
Like a real lady, the female egg is quite picky. It allows only the healthiest sperm to penetrate and fertilize it.
So, if the first sperm to get to it isn’t healthy, nothing is going to happen, if a million sperm gets to it and none of them is healthy, then fertilization will not happen.
However, there is one good thing the crowd of sperm can do, they tend to chip away at her defence, in this case the corona radiate, making it easier for a healthy sperm or perhaps a lucky sperm to swim right through.
Research also shows that, once the eggs is penetrated by the sperm, the outer layers of the egg change instantaneously, instantly rejecting all other sperm and preventing multiple fertilization.
These changes are so distinct that scientists have been able to observe this through a microscope. This is mainly because it takes 46 chromosomes to make a human. This is just right for a sperm and an egg. So, you see, the female eggs takes it time to settle for the best, and remains loyal to that very best. She’s a really high class lady, or you don’t think so?
Even with all the information available about the eggs, there are still some mysterious things about the female eggs, but then, it wouldn’t be a true lady if it lets out all its secrets at once.
While the scientists dig deep into her secrets, I say cheers to the mysterious female eggs.
Ladies, know thy body.
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