Talk:Menstrual cycle

AFAIK, it's just one, and which ovary produces one is random. If there were two eggs, you'd get nonidentical twins. -- Tarquin 22:29 Jan 2, 2003 (UTC)

Alternatively one ovary and then the other, I would say. Randomness would be too complex to implement ;-) --FvdP

It's one egg per menstrual cycle (normally - I'm excluding the use of fertility drugs, abnormal FSH levels, etc.). Left or right ovary is as far as anyone knows, random. -- Someone else 02:55 Jan 8, 2003 (UTC)

How do the two ovaries coordinate this? After all, they are exposed to pretty much the same hormones. "For this month, let's make the following deal: If she eats chocolate on the third day of the cycle, it's your turn, pal." AxelBoldt 04:25 Jan 8, 2003 (UTC)

There's no left/right coordination involved. It's all ovarian tissue, and it all is responsive to FSH, it just happens to be divided into two (sort of like say the adrenal glands: they don't "coordinate" the amount of cortisol they each produce, they just respond equally to the same stimuli). Essentially, the level of FSH increases, stimulates the production of a follicle, the follicle secretes inhibin, which shuts off the FSH, preventing more follicles from developing. So each month, it depends on whether the left or right ovary is the lucky one to develop a follicle first, shutting the other off. If that's not more rather than less confusing?<G> -- Someone else 06:22 Jan 8, 2003 (UTC)

Not confusing at all, thanks. AxelBoldt 17:51 Jan 8, 2003 (UTC)

Ditto. Great explanation, should be put in the article if not already -- Tarquin

Except for false twins when 2 eggs mature at the same time :-)

This said, though the explanation above is very clear to me (I learned that), it is very scientific. Whatabout real life ? I have two ovaries, I feel my body, I talk with my female peers about female stuff; So, I can tell you, I (and many) feel some pain for a couple of hours each time. And each time it's on the opposite side. And each time I wanted to be pregnant, I just waited for the little pain... and there it was ! There's a lot more about menstrual cycle than biological stuff, there are pains, moods, pimples...get real !

Also, it could be mentionned that isolated women such as nons menstrual cycles tend to synchronize.

And this article focuses on human cycle. It would be very interesting to indicate the heat time in animals (or whatever the word is : the fact females of some species accept the males only at the right moment). It is the case for cows, whose cycle is just 28 days as ours...

no mistake ! 21 days for cows !

And, women who are sick or frail because of lack of food, or simply too young (starting age 9-16 ?) or too old (40-55) stop ovulating. Only healthy and able bodies can ovulate.

Also, healthy women who simply exercise excessively are known to stop menstrating while the extreme amounts of exercise continue. --Qaz

I've heard about the ability to tell which side before. Stick-thin models who starve themselves stop ovulating. Agreed, all the above needs mentioning! please add to the article! -- Tarquin 20:34 Jan 8, 2003 (UTC) (one more thing -- I have heard of women who still menstruate while pregnant -- or at least appear to: I don't know if an egg is actually released!)

there are also a couple of examples when a woman gave birth to a 9 month old foetus, and was discovered pregnant from another couple of months one. So, yes, egg is released.

FWIW: The word for the sensation of pain at ovulation is "Mittleschmertz". The 'scientific' word for the period of sexual receptivity (heat) is "estrus", and animals in which this is a prominent feature are usually said to have "estrous" (adjectival form) cycles rather than menstrual cycles. And sometimes a coin flip produces the sequence HTHTHT <G> -- Someone else 21:48 Jan 8, 2003 (UTC)

Do cows menstruate, I mean with blood and everything? AxelBoldt 21:45 Jan 8, 2003 (UTC)

No they don't. *Only* primates bleed.

Actually, bitches (as in female dogs) bleed. I know this because we had to get a nappy for ours so she didn't make too much of a mess. cferrero

I've read that cats dont have a menopause -- but I don't know about the blood. -- Tarquin 21:53 Jan 8, 2003 (UTC)

if most other mammals don't bleed, this raises the question -- why do we? What purpose does it serve? Why have we developed this? I think I'll rearrange a bit tomorrow & put some headings in. But this article is shaping up really nicely! :-) -- Tarquin

maybe primate and humans are just very similar ;-)

The women, the rules and the moon

the researchers for a long time raised the question of sexuality specific to our species, and more precisely the characteristics of female sexuality. The most marked characteristics were the absence of oestrus, the permanent receptivity of the human woman. If there are primates which resemble to us in this respect - especially at species monogamists - that usual, and if is not never marked. An explanation, advanced by Desmond Morris, would be that the woman seeks to keep a man by a more intense and more continuous sexual activity. It was also noticed that the absence of oestrus makes be sure to impregnate his partner, the man must maintain sexual intercourse with it for one period longer than in our cousins. Knight finds these explanations not very convincing. What is marked in the female of our species, he says, is not his constant receptivity, but rather the moment when it is not very receptive - the menstruation. He writes: Despite oestrus loss, hormonally controlled sexual signals are not entirely missing from the human female menstrual cycle. One the contrary, menstruation in human has been accentuated with an external display. It is menstruation rather than ovulation that the human female experiments her behaviour have hormonally influenced to has some degree. Woman lose considerably more blood during menstruation than does any other primate. This shedding of blood, although small, represents a significant loss - has loss which has to Be made good by additional food intake, particularly of iron. The advantage of this has not yet been explained.

(Knight, 1991) menstruation function like a signal. It will say to the men that the woman refuses the sexual intimacy. He notes initially that, if the cycle of fruitfulness is not necessarily related to the phases of the moon - the periodicity of the primates is variable - at the human woman, the typical cycle is about 28,5 days - i.e., that it can coincide very exactly with the lunar cycle. Then, Knight quotes work on the synchronization of periods: certain researchers discovered that when women spend enough time together - in a pension, for example, or a university dortoire, they tend to have their periods at the same time.