rooshvforum.network is a fully functional forum: you can search, register, post new threads etc...
Old accounts are inaccessible: register a new one, or recover it when possible. x


The Physiology of the Female Menstrual Cycle
#1

The Physiology of the Female Menstrual Cycle

The Female Menstrual Cycle - A brief introduction

Let's start with the TL;DR version:
In the Forum Lounge thread, there was some discussion as to when exactly a woman is fertile in her menstrual cycle. This thread is a response to that question.

The answer is: from the date of ovulation (egg release) to the time of her next period. Generally a period of fourteen days.

Note that the date of her last period is irrelevant - what matters is the time of the next period.

Now, exactly deducing this timing is exceptionally difficult for the following reasons: most women do not have the textbook 28 day cycle; most women have slight variations in their cycle time anyway; events in a woman's life can disturb the normal cycle; sometimes the cycle just messes up for no reason. Like economics forecast, trying to figure out the exact date of the next period is often a vague and imprecise exercise.

The time of ovulation is also somewhat unpredictable; but in general, it is fourteen days before the next period. Give or take a day, this is a reasonably hard and fast rule.

For a woman in a textbook 28 day cycle (note that the textbook cycle, in my clinical experience, does not actually exist; it primarily exists as an educational model, not a real world reflection) : she will be fertile for the 14 days before her next period. Assuming she has a 28 day cycle, that will mean she is infertile for the first half/fourteen days of her cycle (which starts on the first day of her last period). She will then be fertile for the next fourteen days/second half of her cycle (which lasts up the first day of her next period.)

Random examples:

For a woman with a 21 day cycle: she will 7 days infertile, then 14 days fertile.

For a woman with 34 day cycle: she will be 21 days infertile, then 14 days fertile.

So fertility is basically the 14 days before a period. After a period, whether she is fertile or not depends purely on the timing of the next period.

Timing when the next period and/or ovulation will occur is referred to as the rhythm method. Because so many factors can cause the period to come earlier or later than expected, the rhythm method is notoriously unreliable to the point where pretty much every medical student is taught this joke to bring home the point:
Q: What do you call patients that decide to use the rhythm method of contraception?
A: Parents.

This is further complicated by the fact that the life span of sperm within the female reproductive tract is variable, but as a rule of thumb, sperm can survive for up to seven days in the female reproductive system. Meaning that even if the woman is not fertile then and there, your sperm may live long enough to catch the egg once it is released. I.e. you may only end up impregnating a woman seven days after intercourse.

In other words, gents, the only time a girl will be well and truly infertile will be during her period, as any egg and sperm will be washed out with the blood. At any other time of her cycle, surprises can and do happen in the real world.

Okay, that was the TL;DR version. Now let's get into the nitty gritty. I will avoid using medical jargon and try to stick to plain English as much as possible.

First up: The Anatomy (very much in brief)

Here's a pic from wikipedia:
[Image: 600px-Blausen_0399_FemaleReproSystem_01.png]

The vagina ends at the cervix. The cervix functions as a gatekeeper into the womb, and can make life easy or difficult for sperm depending on the stage of the menstrual cycle.

The uterus is where babies grow, and is also responsible for menstrual bleeding (hence why menstrual bleeding is also referred to as uterine bleeding).

The ovaries are responsible for hormone production as well as egg release. Much of the uterine cycle is in response to ovarian hormones.

And now, The Ovarian Cycle

So there are multiple cycles in a woman's body: the uterine/menstrual cycle, the breast cycle, the cervical cycle, the skin cycle, etc. But they are all secondary to the brain-ovarian cycle, which is the cycle that rules them all.

So briefly, in as plain English as possible, this is the cycle:

1) The brain detects that there is a low level of oestrogen and progesterone in the blood. The brain freaks out and tells the pituitary gland to activate.

2) The pituitary gland decides to send a message to the ovary, telling it to make more oestrogen. Oestrogen is made in follicles in the ovary. So the pituitary gland releases Follicle Stimulating Hormone, or FSH, into the bloodstream.

3) FSH then activates the development of a bunch of follicles, or stimulates follicles that are already matured.

At this point, you are asking, "Dude, what the heck is a follicle?"

Good question. To keep the discussion simplified, the follicle is basically: A)an egg surrounded by B)a shell of tissue, referred to as the granulosa.

Think of an egg you buy in the supermarket, but instead of a hard shell, the human egg shell is made of body tissue.

Now just as a bird's egg shell is specialised to be a hard protective casing, so too does the human egg shell have a special function - it secretes Oestrogen! The vast majority of a woman's oestrogen comes from these egg shells.

(Now it should make sense to you why, once all the eggs are used up, a woman will enter menopause - because without any eggs, she won't have any egg shells left, and therefore no capacity to make oestrogen).

So that's a follicle. Most eggs in the young adult woman will be dormant with a very tiny shell of tissue, but clumps of them will develop with every cycle under the influence of Follicle Stimulating Hormone. (Eventually, one follicle will become the dominant follicle, will swell up, and burst, releasing the egg. But more on that a little later)

4) As the follicles develop, the granulosa shells of the eggs grow, become more complex, and start secreting oestrogen.

5) As oestrogen builds up in the blood stream, the brain cries out 'TOO MUCH!' and stops releasing FSH

6) However, the oestrogen hijacks the brain and forces the pituitary to release a new hormone, called Luteinising Hormone
, or LH (literally the 'Yellow-making hormone', because it makes granulosa cells turn yellow).

7) Luteinising hormone alters the follicles. Firstly, it can force the human egg to come out of dormancy, especially in the dominant follicle (human eggs are incompletely formed until right before egg release/ovulation). Secondly, it alters the functioning of the egg shell/granulosa: the granulosa starts secreting fluid into the follicle, causing the follicle to swell up into a large cyst. Within this cyst fluid, the egg floats about.

(The swelling up of the follicles often causes pain, which is often referred to as 'mid-cycle pain'. It is very common for women to experience abdominal pains/cramps just before the ovulation, because of these swollen cysts. The pain of these ovarian cysts can sometimes be so severe that it may necessitate and operation to remove the cysts.)

8) At some point, one of the mature follicles decides that it just can't take it anymore, and it bursts, releasing its egg into the wild environs of the female reproductive system. With a bit of luck, this egg will find its way into the uterine tubes, where it may, if destined, meet with a mighty sperm.

9) By now, Oestrogen levels are dropping (because the brain is on strike and refusing to make anymore FSH). With the drop of oestrogen, the levels of LH start to fall as well.

10) The remains of the egg shell, the granulosa, now transform into a new structure, the corpus luteim (literally, the 'yellow structure'). The corpus luteim does something new - it makes progesterone.

11) At this point oestrogen levels, FSH and LH levels are low. The brain is refusing to make either FSH or LH because it is happy that there is progesterone in the blood stream and no more female hormones are required. No oestrogen is made because the follicles fall asleep again. Only the corpus luteum is busy chugging along, pumping out progesterone.

12) However, eventually the corpus luteum exhausts itself. The structure shrivels up and dies. All the cells basically kill themselves off in a mad flurry of progesterone production. They push themselves so hard that they die.

13) With the death of the corpus luteum, progesterone levels fall. Oestrogen levels have been low for a while by now too. The brain freaks out and tells the pituitary gland to activate, starting the whole cycle anew.

This cycle can be interrupted by pregnancy, as the early pregnancy makes its own progesterone; or by hormonal contraception, which prevents the release of FSH and therefore prevents the maturation of egg cells and their granulosa shells.

Now let's go onto the most obvious manifestation of the female reproductive cycle, the Menstrual Cycle:

Menstruation, by definition, is blood loss from the uterus that occurs as part of the normal female reproductive cycle.

Menstruation remains a medical mystery. It is unclear as to why human females menstruate. The vast majority of mammals do not menstruate. In fact, only some primates, some bats, and the elephant shrew have menstrual cycles (of interest, is that menstruation seems to have developed independently in these three groups i.e. there is no menstruating ancestor held in common). Some mammals (eg dogs) do have something called an oestrus cycle, but this causes vaginal bleeding, not menstrual bleeding.

Menstrual bleeding causes iron deficiency, anemia, low blood volume, and can predispose to nasty infections. It appears, at first glance, to be evolutionarily disadvantageous - women routinely can become severely ill due to their menstrual cycle. Yet, it must have some evolutionary advantage to have occurred, but this is a different discussion that I will not go into in this post.

Now we have already established that there is an ovarian cycle, and that it release oestrogen before the egg is released, and then progesterone after the egg is released. The uterus responds to each of these hormones.

Oestrogen causes the inner lining, the endometrium, of the uterus to grow and become thick and cushiony. You could say that oestrogen prepares the uterus to receive the egg, by making a pleasant environment for the egg to fertilise in. When oestrogen levels fall, progesterone takes over.

Progesterone is a maintainer - it doesn't cause the endometrium to grow, but it does prevent it from decaying. It also causes the endometrium to be rich with blood and nutrient, in case a fertilised egg comes along and needs to grab a snack.

So what happens when both oestrogen and progesterone levels fall, which is what occurs as the corpus luteum dies?

Well, then there is nothing to grow the endometrium and there is nothing to maintain the endometrium.

So it dies off. This process can be painful and causes pre-menstrual cramps, which is literally the feeling of blood flow being cut off to the endometrium (similar to the kind of pain you experience if you run and your muscles just can't get enough blood and you start cramping).

As the endometrium dies off, it tears the blood vessels embedded within it. These blood vessels bleed into the uterus.

Blood accumulates and then the combined blood-dead tissue mix pour out of the uterus, via the vagina, as a period.

Once oestrogen levels build up again, then the uterine lining heals itself and starts growing again, and the period finally stops. Periods can also be stopped by giving a women progesterone or oestrogen, for example with hormonal contraceptives.

A very brief note on the vaginal and cervical cyles:
Oestrogen makes the vagina and cervix wet and moist, with secretions that provide sperm with nutrition. Therefore, women are more likely to be wet just before ovulation, due to the effects of oestrogen.

Progesterone assumes that the egg has been fertilised already and it tries to prevent further sperm coming in. The vagina and cervix become dry and have a thick, sticky secretion that is full of white blood cells that will try to destroy sperm. Women can be very dry after ovulation.

Congratulations if you made it this far. You now know more than most women know about the female reproductive cycle. Any questions?
Reply
#2

The Physiology of the Female Menstrual Cycle

Yes - Can one get infected or otherwise harmed when having sex with a woman on her period? I'm not talking about STDs, just in general. I remember reading old biblical texts that say one shouldn't be around a woman when she has her period or let her cook food.

Also, what do you think the advantages and disadvantages are of the menstrual cycle, do you think?

G
Reply
#3

The Physiology of the Female Menstrual Cycle

Good write up. Didn't think I'd learn anything but I did.

I would like to clarify one thing. Not that you're wrong, but just to clarify.

"Now, exactly deducing this timing is exceptionally difficult for the following reasons: most women do not have the textbook 28 day cycle;
..."


Most fertile women (let's just say 18-24) have a cycle very close to 29.5 days (+/- 1 day). This is significant enough to have warranted a meta study that found these women had periods that aligned with the lunar cycles.

No doubt this would be ignored or denied by many, as far more women and the men patronizing them are older and beyond peak fertility age...but it's true.

Quote:Quote:

By selecting the subpopulation of women (approximately 30%) who cycle as often as the moon does, i.e. 29.5+1 day, a significant pattern was revealed. There was an increased likelihood of menstruation onset in the light half of the lunar month.
...
the most fertile reproductive cycle has the same length as the lunar cycle

thread-24122...#pid716259

I wonder if the purpose of the menstrual cycle was increased fertility. I know one theory on why women sync up is because of competition...the potency of male sperm drops way off after the first load, so all the chics want to be the first one to the dick.

So if menstruation can increase fertility (even just for a few days), it would encourage population growth.

“Until you make the unconscious conscious, it will direct your life and you will call it fate.”
Reply
#4

The Physiology of the Female Menstrual Cycle

Quote: (09-28-2015 08:59 AM)Geomann180 Wrote:  

Yes - Can one get infected or otherwise harmed when having sex with a woman on her period? I'm not talking about STDs, just in general. I remember reading old biblical texts that say one shouldn't be around a woman when she has her period or let her cook food.

Also, what do you think the advantages and disadvantages are of the menstrual cycle, do you think?

G

Regarding your first question: Blood is a natural bacterial culture medium. Women are far more likely to become ill with a uterine infection if they have sex during their period.

In the age of antibiotics, this may not be such a big deal, but pre-antibiotics, uterine infection would slowly destroy the health of the uterine lining, in effect making a woman infertile (assuming the infection was not severe enough to kill the woman off outright). The biblical texts are more for the protection of the woman's fertility than for protecting the man.

If a woman already has an STD, a period will probably make her more infectious to you as a man. But overall, the risks are heavily on the woman's side, they have more to lose from having unprotected sex while on a period. Note that you do not even have to have a classical STD to give a woman a uterine infection - some otherwise normal bacteria from your skin can piggyback on your semen and cause an infection once they discover all that blood they can feed on.

As to your second question regarding the advantages of the menstrual cycles, this is still a matter of scientific debate. However, here is a bit of a discussion of why maybe menstruation exists:

One common feature of all menstruating animals is that they have invasive embryos.

In most animals, fertilised eggs hang out in the uterine cavity, and let the endometrium come to them.

In menstruating animals, the fertilised eggs are invasive - they eat their way into the uterine wall, and the pregnancy develops, in the initial stages, not in the uterus cavity but in the wall:
[Image: implantation-1.gif]

This is unusual in the mammalian kingdom, and puts the mother at risk. The little bastards may end up eating their way through the uterus wall and basically make a hole in the uterus, which is not good of the mother or the pregnancy.

It is thought that, as a defensive mechanism against this invasive little parasite, that women developed a thickened endometrial wall. This explains the sheer volume of endometrial tissue and blood that is released in a period.

Which still leaves the question - why should the endometrial wall die off? Why not just keep the wall around for a while?

It is possible that if the wall did not shed, that numerous invasions of multiple failed pregnancies may build up in the uterine wall, creating a hostile environment for freshly fertilised eggs. By having a menstruation, any eggs that fail to implant will be washed out and this will prevent interference with the next egg in the cycle. It will also ensure that defective fertilised eggs, that are a bit slower and less evolutionarily fit, will be killed off if they do not eat their way into the uterine wall in the given time limit.

But as I said, this is scientific speculation. No one knows exactly why menstruation exists and there are other theories, but the above is currently the most accepted, generally.

As far as disadvantages go, menstruation causes a loss of hemoglobin, blood fluid, and iron; amongst other nutrients. In times of starvation/deprivation, menstruation may actually push a woman into malnourishment. Even well nourished women tend to develop iron deficiency because of menstruation.

At times, menstrual bleeding can be so severe as to be life-threatening.

Furthermore, for most women, menstruation is painful and can be disruptive for normal day-to-day activities, effectively lowering quality of life for women.
Reply
#5

The Physiology of the Female Menstrual Cycle

Thanks for the write up Thomas.

So let's say, you have a nagging suspicion that you impregnated the girls during the last 4-7 days, is there anything you can do to prevent pregnancy short of an abortion? Since it's not possible to detect pregnancy that soon.

Ass or cash, nobody rides for free - WestIndiArchie
Reply
#6

The Physiology of the Female Menstrual Cycle

Quote: (09-28-2015 09:46 AM)heavy Wrote:  

I would like to clarify one thing. Not that you're wrong, but just to clarify.

"Now, exactly deducing this timing is exceptionally difficult for the following reasons: most women do not have the textbook 28 day cycle;
..."


Most fertile women (let's just say 18-24) have a cycle very close to 29.5 days (+/- 1 day). This is significant enough to have warranted a meta study that found these women had periods that aligned with the lunar cycles.

No doubt this would be ignored or denied by many, as far more women and the men patronizing them are older and beyond peak fertility age...but it's true.

I did a quick pubmed search, there seem to be more research articles disproving the link between menstrual and lunar cycles than proving.

Example:
http://www.ncbi.nlm.nih.gov/pubmed/23889481

Furthermore, in the vary study you cited, the authors themselves show in table one that women vary wildly in the length of their cycle, with the actual amount of women having a 29+/-1day cycle only being 26-31%. This is hardly a massive majority.

Overall, the evidence seems to suggest that there is no link. Obviously, as new evidence arises, this conclusion can be subject to change.
Reply
#7

The Physiology of the Female Menstrual Cycle

Quote: (09-28-2015 09:55 AM)Dalaran1991 Wrote:  

Thanks for the write up Thomas.

So let's say, you have a nagging suspicion that you impregnated the girls during the last 4-7 days, is there anything you can do to prevent pregnancy short of an abortion? Since it's not possible to detect pregnancy that soon.

Disclaimer: None of the following actually constitutes medical advice. It's just medical information given for educational reasons. Consult a doctor if you need help with a medical problem for you or your partner, not some guy on the internet.

- Provided that ovulation has not yet occurred, but you suspect your sperm is there waiting in ambush: an emergency contraceptive containing a high level of progesterone will suppress luteinising hormone, effective preventing the release of the egg. If the egg has been released but not yet fertilised, the progesterone will flood the uterus with white blood cells that will eat up the sperm. Emergency contraception is about 75% effective and is generally available at pharmacies without a prescription, although local laws may vary.

- If the egg has already been fertilised, but has not yet implanted itself on the abdominal wall, insertion of an intra-uterine contraceptive device can make the uterus too hostile for pregnancy. (The exact reason with intra-uterine devices prevent pregnancy implantation is still unknown. The technique itself is ancient - in the middle ages, women would stick stones in the uterus as a contraceptive method). That said, this may just end up causing a life-threatening ectopic pregnancy (a pregnancy that has settled outside of the uterus and instead of dying off, manages to somehow survive. The destruction the invasive embryo usually eventually causes massive bleeding.) This will require a trained healthcare professional to insert it for you.

- If the egg is fertilised and implanted into the uterine wall, then by definition it is a viable pregnancy and any termination of the pregnancy is an abortion. This will require a trained healthcare professional.

- Various herbal and traditional methods exist but they basically do the same thing as medical treatments, but even less reliably. Not recommended.
Reply
#8

The Physiology of the Female Menstrual Cycle

Can the birth control pill delay menopause for women in their early 40's if meopause hasnt begun yet?
Reply
#9

The Physiology of the Female Menstrual Cycle

Quote: (09-28-2015 10:26 AM)rpg Wrote:  

Can the birth control pill delay menopause for women in their early 40's if meopause hasnt begun yet?

Follicles naturally die off in a process called atresia. So even if the eggs are not released, they are not exactly preserved either - they still die.

Just to give you an idea of the extent of the carnage:
Human females are generally born with about 6-7 million follicles (i.e. eggs + egg shells)
By puberty, only about 400 000 have survived.
A woman will typically only menstruate about 500 times in her life, i.e. she will only have 500 ovulations.

So only about 500 of the original 7 million eggs are actually released. The rest just uselessly die off. Once they have all died, menopause starts.

So even if the ovulation process is halted through hormonal contraception, this process of dying off is not halted for the follicles.

[Image: 46077740gbiha_sm.jpg]
Reply
#10

The Physiology of the Female Menstrual Cycle

Quote: (09-28-2015 10:46 AM)Thomas the Rhymer Wrote:  

Quote: (09-28-2015 10:26 AM)rpg Wrote:  

Can the birth control pill delay menopause for women in their early 40's if meopause hasnt begun yet?

Follicles naturally die off in a process called atresia. So even if the eggs are not released, they are not exactly preserved either - they still die.

Just to give you an idea of the extent of the carnage:
Human females are generally born with about 6-7 million follicles (i.e. eggs + egg shells)
By puberty, only about 400 000 have survived.
A woman will typically only menstruate about 500 times in her life, i.e. she will only have 500 ovulations.

So only about 500 of the original 7 million eggs are actually released. The rest just uselessly die off. Once they have all died, menopause starts.

So even if the ovulation process is halted through hormonal contraception, this process of dying off is not halted for the follicles.

[Image: 46077740gbiha_sm.jpg]
Thanks.
Another question I have never gotten to the bottom of is where are high T women getting the testosterone? Ovaries? A high T woman is a very unique creature especially if with all the trimmings of beauty.
Reply
#11

The Physiology of the Female Menstrual Cycle

Quote: (09-28-2015 11:03 AM)rpg Wrote:  

Quote: (09-28-2015 10:46 AM)Thomas the Rhymer Wrote:  

Quote: (09-28-2015 10:26 AM)rpg Wrote:  

Can the birth control pill delay menopause for women in their early 40's if meopause hasnt begun yet?

Follicles naturally die off in a process called atresia. So even if the eggs are not released, they are not exactly preserved either - they still die.

Just to give you an idea of the extent of the carnage:
Human females are generally born with about 6-7 million follicles (i.e. eggs + egg shells)
By puberty, only about 400 000 have survived.
A woman will typically only menstruate about 500 times in her life, i.e. she will only have 500 ovulations.

So only about 500 of the original 7 million eggs are actually released. The rest just uselessly die off. Once they have all died, menopause starts.

So even if the ovulation process is halted through hormonal contraception, this process of dying off is not halted for the follicles.

[Image: 46077740gbiha_sm.jpg]
Thanks.
Another question I have never gotten to the bottom of is where are high T women getting the testosterone? Ovaries? A high T woman is a very unique creature especially if with all the trimmings of beauty.

The only place a woman would get testosterone without added androgens would be the pituitary gland in the brain. Genetics would determine how much test is actually secreted.

As for masculinized behavior, it stands to reason that what you think of as "high test" is probably not that much extra testosterone. She maybe on the right side of the bell curve, but it is a far cry away from your average male.
Reply
#12

The Physiology of the Female Menstrual Cycle

Quote: (09-28-2015 11:03 AM)rpg Wrote:  

Thanks.
Another question I have never gotten to the bottom of is where are high T women getting the testosterone? Ovaries? A high T woman is a very unique creature especially if with all the trimmings of beauty.

That's a great question, I had to look up the answer.

Testosterone in women is generated by the ovarian stroma (a type of tissue that has nothing to do with the follicle), the adrenal glands (specifically the adrenal cortex), with the rest being generated by other tissues.

It seems that most tissue in the female body is able to generate testosterone.

The actual percentages of testosterone production are: ovary 25%, adrenal glands 25%, other tissues 50%

So most of the testosterone in a woman's body is not made by any specific organ, but her human tissue in general.

Testosterone in women also does not follow a cycle. It is made at a constant level, and even persists beyond menopause.

Testosterone in women is created mostly by enzyme conversion from other molecules, specifically through conversion of cholesterol and progesterone. The testosterone released by the ovary is most likely converted progesterone, but as noted above, ovarian testosterone is only about 25% of the total.

My source:
http://www.fertstert.org/article/S0015-0...2985-0/pdf
Reply
#13

The Physiology of the Female Menstrual Cycle

Menstruation data sheet.

I've seen it all now.

Bravo though to be fair.
Reply
#14

The Physiology of the Female Menstrual Cycle

[Image: 264.gif]

That was really good.

As men, I believe we all need to educate ourselves on this. Know how to not be a dad.
Reply
#15

The Physiology of the Female Menstrual Cycle

I appreciate your follow through and putting together this OP and the follow through on the various questions. .. your information seems very well backed up by modern knowledge and explained in fairly layman's terms, even though at this particular moment some of it is beyond my desire to know that level of detail... nonetheless, I believe at some time in the future, if I or someone else were to want to go back to reference actual information and mechanisms, the OP and your follow-up responses will be a good references for such.

I think that you fairly thoroughly explained the fertility periods, which seems to have been a much better explanation compared with the charts and even some of the other scientific information that is put out for the public. From some of those charts, we were getting the sense that a woman had a peak period of fertility during the middle of her cycle (between menstruations) and both before and after her period were supposedly "safe periods" to ejaculate within her without worries of pregnancy.

Your various explanations really dispel those misinformation frameworks.

In some sense, you are description is getting me back to my original understanding, and that is that the best time to NOT worry about getting a woman pregnant is during her period.. and the risks go up day by day, once the bleeding stops.

I do find it interesting, however, to consider that a sperm could potentially survive for 7 days.. and surely, I have NO doubts about that potentiality because if thousands of sperm are floating around in the uterus or some other connected part of the female anatomy, then surely the conditions could be warm and friendly for sperm survival.

When I am having sex with unknown (or recently met girls), I frequently do tend to go bareback with them, and employ withdrawal - however, I do understand as well that some sperm can still be in the pre-ejaculation fluids, and I kind of wonder about how much sperm is potentially in pre-ejaculation fluids. Is there any reliable and well though out studies that get into the details of pre-ejaculation fluids or looking into whether guys really are successfully pulling out before any actual ejaculation fluid gets into the girl? I'm in my late 40s, so have I just gotten lucky to date, because I do NOT know of any girl who has accidentally gotten pregnant from me frequently using the withdrawal method? Surely, sometimes, the girl may be on the pill or something (because we may NOT get to that level of questioning, but even if she says that she is on the pill, I will in many instances just pull out, in case she is NOT quite truthful... [Image: lol.gif] )
Reply
#16

The Physiology of the Female Menstrual Cycle

Quote: (09-28-2015 11:23 AM)Thomas the Rhymer Wrote:  

Quote: (09-28-2015 11:03 AM)rpg Wrote:  

Thanks.
Another question I have never gotten to the bottom of is where are high T women getting the testosterone? Ovaries? A high T woman is a very unique creature especially if with all the trimmings of beauty.

That's a great question, I had to look up the answer.

Testosterone in women is generated by the ovarian stroma (a type of tissue that has nothing to do with the follicle), the adrenal glands (specifically the adrenal cortex), with the rest being generated by other tissues.

It seems that most tissue in the female body is able to generate testosterone.

The actual percentages of testosterone production are: ovary 25%, adrenal glands 25%, other tissues 50%

So most of the testosterone in a woman's body is not made by any specific organ, but her human tissue in general.

Testosterone in women also does not follow a cycle. It is made at a constant level, and even persists beyond menopause.

Testosterone in women is created mostly by enzyme conversion from other molecules, specifically through conversion of cholesterol and progesterone. The testosterone released by the ovary is most likely converted progesterone, but as noted above, ovarian testosterone is only about 25% of the total.

My source:
http://www.fertstert.org/article/S0015-0...2985-0/pdf

Great answer, thank you for correcting my misinformation!

What's your background Thomas? Do you have a OBGYN datasheet coming out soon [Image: cool.gif]
h
Reply
#17

The Physiology of the Female Menstrual Cycle

Some more questions:

-I've read many times that women are the most fertile 2 days before and after the 14th day of their period, I assume now that this is mainly said because the 14th day is just an estimate + the fact that the sperm can stay alive, hence 2 days before ovulation is still dangerous, because if we were certain to know when a girl would ovulate and disregarding the sperm can stay alive fact then 1 or 2 days before ovulation she would be infertile correct?

-what info do you have on mood changes during various phases of the cycle. We generally know many girls are hornier during ovulation and crankier during menstruation. What else can you tell us? Also my current girl is on her best behavior during menstruation actually and the worst the 1-2 days before she starts bleeding. She might be a special case. From my experience girls are the horniest during both menstruation and ovulation, although in the former they will be more resistant due to the messiness.

-does alcohol affect the chance of impregnating a girl (alcohol on the men and/or on the females side)?

-is there any scientific evidence that girls are more likely to get pregnant when they are really into the guy? I've heard also when the girl has an orgasm the chance increases correct?

And not sure if you have good info on this, but if you do, feel free to share. How does the pill influence female psychology?
Reply
#18

The Physiology of the Female Menstrual Cycle

Great write up. In my experience girls get incredibly horny the first few days of their period. I have heard this from girls I have dated, female friends, and guys who said the same thing.

Why is that? Any idea? From what I understand, if I read this correctly, the first two or three days of her period would be when she isn't fertile because her fertility window just closed. So, why horny?

My dad was an OBGYN and he said that in the early days, I forget which cases this was used for, he would double up hormonal Birth Control and give it to women in his practice to induce abortions. This was way back in the day in a state where it was difficult to get an abortion. Also, from what I remember him telling me this was in the first few weeks because beyond that it required surgery.

My thinking is, OBVIOUSLY DO NOT DO ANYTHING ILLEGAL, if this is true then it might make an effective plan b pill. Any details on how that would work. I will ask him at some point and compare his info with yours.

Edit:

Apparently this was pre-morning after pill and doctors would make up their own concoction to do the same thing the morning after pill does today.

So, according to my dad and his recipe, within 72 hours he would prescribe HBC to be taken once in the morning and once at night for three to four days. This would create inhospitable conditions in the uterus stopping implanting. The downside was that it would cause a lot of cramping and nausea for a few days.

Not sure if this will help any of us, but if you end up needing a morning after pill in a country that doesn't sell them or you don't have the cash then this is one option other than waiting and ponying up the money for an abortion down the road.

Women these days think they can shop for a man like they shop for a purse or a pair of shoes. Sorry ladies. It doesn't work that way.

Women are like sandwiches. All men love sandwiches. That's a given. But sandwiches are only good when they're fresh. Nobody wants a day old sandwich. The bread is all soggy and the meat is spoiled.

-Parlay44 @ http://www.rooshvforum.network/thread-35074.html
Reply
#19

The Physiology of the Female Menstrual Cycle

Quote: (09-28-2015 09:54 AM)Thomas the Rhymer Wrote:  

One common feature of all menstruating animals is that they have invasive embryos.

In most animals, fertilised eggs hang out in the uterine cavity, and let the endometrium come to them.

In menstruating animals, the fertilised eggs are invasive - they eat their way into the uterine wall, and the pregnancy develops, in the initial stages, not in the uterus cavity but in the wall:

This is unusual in the mammalian kingdom, and puts the mother at risk. The little bastards may end up eating their way through the uterus wall and basically make a hole in the uterus, which is not good of the mother or the pregnancy.

It is thought that, as a defensive mechanism against this invasive little parasite, that women developed a thickened endometrial wall. This explains the sheer volume of endometrial tissue and blood that is released in a period.

Fascinating, I´ve never heard or read about this before.
Great stuff Thomas, it´s interesting that the process, purpose and evolution of menstruation is still not completely understood. For example I just read a bit about it on wikipedia, and it turns out that menstruation is actually a rare thing among other mammals. It can only be found in some primates, some bats and a little critter called the elephant shrew.
It´s one of those things you never think about as it seems to be such an unremarkable, natural part of life. But it´s actually quite exceptional.

On a less serious note, when reading the quoted paragraph immediately a certain scene from the movie Alien came to my mind.
Well played, Mr. Giger, well played indeed.
[Image: biggrin.gif]
Reply
#20

The Physiology of the Female Menstrual Cycle

Quote: (09-28-2015 07:09 PM)Celtic_Austrian Wrote:  

Quote: (09-28-2015 09:54 AM)Thomas the Rhymer Wrote:  

One common feature of all menstruating animals is that they have invasive embryos.

In most animals, fertilised eggs hang out in the uterine cavity, and let the endometrium come to them.

In menstruating animals, the fertilised eggs are invasive - they eat their way into the uterine wall, and the pregnancy develops, in the initial stages, not in the uterus cavity but in the wall:

This is unusual in the mammalian kingdom, and puts the mother at risk. The little bastards may end up eating their way through the uterus wall and basically make a hole in the uterus, which is not good of the mother or the pregnancy.

It is thought that, as a defensive mechanism against this invasive little parasite, that women developed a thickened endometrial wall. This explains the sheer volume of endometrial tissue and blood that is released in a period.

Fascinating, I´ve never heard or read about this before.
Great stuff Thomas, it´s interesting that the process, purpose and evolution of menstruation is still not completely understood. For example I just read a bit about it on wikipedia, and it turns out that menstruation is actually a rare thing among other mammals. It can only be found in some primates, some bats and a little critter called the elephant shrew.
It´s one of those things you never think about as it seems to be such an unremarkable, natural part of life. But it´s actually quite exceptional.

On a less serious note, when reading the quoted paragraph immediately a certain scene from the movie Alien came to my mind.
Well played, Mr. Giger, well played indeed.
[Image: biggrin.gif]

Seems like a sign of abundance to be able to bleed out nutrients - once a month.... or aliens... [Image: confused.gif]
Reply
#21

The Physiology of the Female Menstrual Cycle

Quote: (09-28-2015 02:35 PM)JayJuanGee Wrote:  

I think that you fairly thoroughly explained the fertility periods, which seems to have been a much better explanation compared with the charts and even some of the other scientific information that is put out for the public. From some of those charts, we were getting the sense that a woman had a peak period of fertility during the middle of her cycle (between menstruations) and both before and after her period were supposedly "safe periods" to ejaculate within her without worries of pregnancy.

...

I do understand as well that some sperm can still be in the pre-ejaculation fluids, and I kind of wonder about how much sperm is potentially in pre-ejaculation fluids. Is there any reliable and well though out studies that get into the details of pre-ejaculation fluids or looking into whether guys really are successfully pulling out before any actual ejaculation fluid gets into the girl?

Thank you for your questions and comments.

With regards to your first comment: Thanks for bringing this up, I completely forgot to discuss this aspect. Although a woman can fall pregnant with a fertilized egg anytime before the next period, unfertilized eggs are thought to die within 48 hours.

The ovary will release an egg at ovulation, but sometimes less dominant follicles will release another egg after the first one, even up to a few days later. (That's how you get non-identical twins)

So if you wait for all the potential eggs to die off, you can then safely release sperm into her without causing pregnancy.

Timing the egg die-off is so notoriously unreliable that it is not recommended; it's safer to assume she can fall pregnant anytime before the period.

With regards to your second comment, please see this post and the follow up discussion:
thread-18970...#pid345530

For a deeper discussion of contraceptive methods:
thread-40893...#pid842604
Reply
#22

The Physiology of the Female Menstrual Cycle

Quote: (09-28-2015 03:07 PM)rottenapple Wrote:  

Some more questions:

-I've read many times that women are the most fertile 2 days before and after the 14th day of their period, I assume now that this is mainly said because the 14th day is just an estimate + the fact that the sperm can stay alive, hence 2 days before ovulation is still dangerous, because if we were certain to know when a girl would ovulate and disregarding the sperm can stay alive fact then 1 or 2 days before ovulation she would be infertile correct?

-what info do you have on mood changes during various phases of the cycle. We generally know many girls are hornier during ovulation and crankier during menstruation. What else can you tell us? Also my current girl is on her best behavior during menstruation actually and the worst the 1-2 days before she starts bleeding. She might be a special case. From my experience girls are the horniest during both menstruation and ovulation, although in the former they will be more resistant due to the messiness.

-does alcohol affect the chance of impregnating a girl (alcohol on the men and/or on the females side)?

-is there any scientific evidence that girls are more likely to get pregnant when they are really into the guy? I've heard also when the girl has an orgasm the chance increases correct?

And not sure if you have good info on this, but if you do, feel free to share. How does the pill influence female psychology?

With regards to your first question: assuming that a woman has a textbook 28 day cycle (which doesn't really exist) and assuming that a woman releases only one egg at ovulation and does not have any follow up eggs, then she will ovulate at day 14, and by day 16 the egg will have died if it has not been fertilized. Since a woman can release follow-up eggs after the first one, and since most women's cycles are not really 28 days, that model is an oversimplification.

Second question: there is a pre-ovulation syndrome and a pre-menstrual syndrome. The exact symptoms/signs of the syndromes vary between individuals, but in general: pre-ovulation is accompanied by better mood, need to socialise, flushing of the lips and cheeks, breast and buttock enlargement, increased vaginal fluids. Pre-menstrual syndrome is accompanied by irritableness, mood swings, bloatedness, constipation, and genital dryness.

The exact causes of these syndromes are thought to be due to the effect of peak blood oestrogen for pre-ovulation and due to the peak and fall of progesterone levels for pre-menstrual syndrome. That said, pre-ovulation and PMS are both very poorly understood and the exact mechanisms underlying them have not been discovered. The person or team that discovers exactly what PMS is on a biological/cell level could very well win a nobel peace prize, because it has remained a stubborn mystery for a while now.

Third question: strictly speaking, alcohol is toxic to sperm, so technically it should reduce the chances of pregnancy; but realistically speaking, alcohol increases the chance of having unplanned unprotected sex, so it balances out. On the females side, alcohol may destroy the egg if there is a high enough concentration at the uterine wall, but that will have to happen several days after fertilization, when the egg tries to implant itself.

Put it this way: despite being toxic, alcohol seems to cause more pregnancies than it prevents.

Fourth question: A girl who is into a guy or who is having an orgasm will release vaginal, cervical and uterine fluids which are very sperm friendly, containing lots of nutrients for the sperm to eat, lots of water to make it easier for the sperm to swim, and very few defense mechanisms to prevent killing of sperm. So yes, this can increase the chances of pregnancy, but it is not a requirement.

If you are more interested in sperm and how they get to the egg, this is a great introductory video:





Fifth question: the female contraceptive pill works by suppressing the release of either LH or FSH. Without these hormones, follicles cannot mature their eggs and also cannot release their eggs. This is done by maintaining high levels of progesterone and/or oestrogen in the blood stream, which shuts down the brain's desire to create LH or FSH.

Other effects on physiology depend on the woman, and there is a great variation in effects, but commonly: improvement in skin (this is due to high hormone levels cancelling out testosterone effects), bloating, constipation, water retention, mood changes, personality changes, weight gain. Most of the bad side effects on a woman's body are due to the effects of Progesterone, which causes water retention.

There is also some conflicting evidence with regards to some cancers, but if a woman develops a hormone responsive cancer, she may make it worse by being on the pill. The pill also speeds up blood clotting, which in some women can cause thrombosis, especially if they are also smokers.
Reply
#23

The Physiology of the Female Menstrual Cycle

Quote: (09-28-2015 06:21 PM)Troll King Wrote:  

Great write up. In my experience girls get incredibly horny the first few days of their period. I have heard this from girls I have dated, female friends, and guys who said the same thing.

Why is that? Any idea? From what I understand, if I read this correctly, the first two or three days of her period would be when she isn't fertile because her fertility window just closed. So, why horny?

Women are just weird. Maybe they feel excited because they know they won't fall pregnant.

I've had the opposite experience, personally.
Reply
#24

The Physiology of the Female Menstrual Cycle

Quote: (09-28-2015 08:59 AM)Geomann180 Wrote:  

I remember reading old biblical texts that say one shouldn't be around a woman when she has her period or let her cook food.

I've known a few that rule applies to the other 3 weeks of the month as well

_______________________________________
- Does She Have The "Happy Gene" ?
-Inversion Therapy
-Let's lead by example


"Leap, and the net will appear". John Burroughs

"The big question is whether you are going to be able to say a hearty yes to your adventure."
Joseph Campbell
Reply
#25

The Physiology of the Female Menstrual Cycle

Thanks for the right up TtR. Very informative.

So a woman who is very attuned to her body can "know" that she is highly fertile starting from when she experiences cramps up to the time she menstruates? And somewhat fertile for as long as 7 days before the cramps because of the long shelf life of sperm?

TtR, do you have any thoughts about how evolutionary factors influence which egg ends up being fertilised? With sperm there are zillions, and it is clear there is a sort of battle between them, and the most "fit" end up fertilising the egg. Do you think something similar happens with eggs? There are obviously far fewer eggs, but even if a woman is constantly pregnant during her lifetime only a small portion of her eggs will be fertilised. Is there any indication of a selection mechanism that allows the most fit eggs to be the ones that are fertilised?
Reply


Forum Jump:


Users browsing this thread: 1 Guest(s)