
The phrase menstrual cycle ( or ''period'') refers to the recurring physiology changes in a female's body that are under the control of the reproduction hormone system and necessary for reproduction. In women, menstrual cycles occur typically on a monthly basis between puberty and menopause. Besides humans, only great apes exhibit menstrual cycles, in contrast to the estrus cycle of most mammalian species. ==Overview== During the menstrual cycle, the sexually mature female body develops one egg (or occasionally two, which might result in non-identical twins) and releases it at the time of ovulation. The lining of the uterus, the endometrium, builds up in a synchronised fashion. After ovulation, this lining changes to prepare for potential implantation of the fertilized egg to establish a pregnancy. If fertilisation and pregnancy do not ensue, the uterus sheds the lining and a new menstrual cycle begins. The process of the shedding of the lining is called menstruation. Menstruation manifests itself to the outer world in the form of the menses ( also ''menstruum''): essentially part of the endometrium and blood products that pass out of the body through the vagina. Although this is commonly referred to as ''blood'', it is differs in composition from venous blood. Common usage refers to menstruation and menses as a period. This bleeding serves as a sign that pregnancy has not taken place. (However, this cannot be taken as certainty, as sometimes there is some bleeding in early pregnancy.) During the reproductive years, failure to menstruate may provide the first indication to a woman that she may have become pregnant. A woman might say that her "period is late" when an expected menstruation has not started and she might have become pregnant. Menstruation forms a normal part of a natural cyclic process occurring in healthy women between puberty and end of the reproductive years. The onset of menstruation, known as ''menarche'', occurs at an average age of 12, but can occur any time between the ages of 8 and 16. The last period, menopause, usually occurs between the ages of 45 and 55. Deviations from this pattern deserve medical attention. Amenorrhea refers to a prolonged absence of menses during the reproductive years of a woman for reasons other than pregnancy. For example, women with very low body fat, such as athletes, may cease to menstruate. The presence of menstruation does not prove that ovulation took place, and women who do not ovulate may have menstrual cycles. Those anovulatory cycles tend to take place less regularly and show greater variation in cycle length. == The normal menstrual cycle in humans == While cycle length may vary, 28 days is generally taken as representative of the normal ovulatory cycle in women. Convention uses the onset of menstrual bleeding to mark the beginning of the cycle, so the first day of bleeding is called "Cycle Day one". One can divide the menstrual cycle into four phases: ===Menstruation=== Menstruation lasts for a few days (usually 3 to 5 days, but anywhere from 2 to 7 days is considered normal) and involves the loss of about 1 E-5 m3 of blood (including shed endometrium). An enzyme called plasmin — contained in the endometrium — inhibits the blood from blood clotting. Because of this blood loss, women have higher dietary requirements for iron than do males — to prevent iron deficiency (medicine). Many women experience uterine cramps, also referred to as dysmenorrhea, during this time. A vast industry has grown to provide sanitary products to help women to manage their menses. ===Follicular phase=== Under the influence of follicle stimulating hormone (FSH) a number of follicles in the ovary start to grow and, in turn, produce estrogens, primarily estradiol. These estrogens initiate the development of a new layer of endometrium with the development of a typical histologic pattern termed the proliferative endometrium. The estrogens provide a negative feed-back loop to the pituitary gland and decrease the secretion of FSH. Inhibin secreted by the largest follicle also decreases FSH. Typically only the most advanced follicle (lead follicle) can develop further as it has more FSH receptors; the other follicles stop growing. This way, normally only one egg will mature in a given cycle. ===Ovulation=== When the follicle has matured, it secretes enough estradiol to trigger the acute release of luteinizing hormone (LH). In the 28-day cycle this LH surge starts around cycle day 12 and may last 48 hours. The release of LH matures the egg and weakens the wall of the follicle in the ovary. This process leads to ovulation: the release of the now mature ovum, the largest cell of the body (with a diameter of about 1 E-4 m). Which of the two ovaries — left or right — ovulates appears essentially random; no known left/right co-ordination exists. The Fallopian tube needs to capture the egg and provide the site for fertilization. A characteristic clear and stringy mucus exhibiting spinnbarkeit develops at the cervix, ready to accept sperm from intercourse. In some women, ovulation features a characteristic pain called ''Mittelschmerz'' which lasts for several hours. Many women perceive the vaginal and cervical mucus changes at ovulation, particularly if she is monitoring herself for signs of fertility. An unfertilised egg will disintegrate. ===Luteal phase=== After ovulation, the residual follicle transfoms into the corpus luteum under the support of the pituitary homones. This corpus luteum will produce progesterone in addition to estrogens for the next 2 weeks. Progesterone plays a vital role in converting the proliferative endometrium into a secretory lining receptive for implantation and supportive of the early pregnancy. It raises the body temperature slightly, thus woman who record their temperature on a daily basis will notice that they have entered the luteal phase. If fertilisation of an egg has occurred, it will travel as an early embryo through the tube to the uterine cavity and implant itself about 5 to 7 days after ovulation. Shortly after implantation, the growing embryo will signal its existence to the maternal system . One very early signal consists of human chorionic gonadotropin (hCG), a hormone that pregnancy tests can measure. This signal has an important role in maintaining the corpus luteum and enabling it to continue to produce progesterone. In the absence of a pregnancy and without hCG, the corpus luteum demises and inhibin and progesterone levels fall. This will set the stage for the next cycle. Progesterone withdrawal leads to menstrual shedding (''progesterone withdrawal bleeding''), and falling inhibin levels allow FSH levels to rise to raise a new crop of follicles. ==Menstrual symptoms== In many women, various unpleasant symptoms caused by the involved hormones and by cramping of the uterus can precede or accompany menstruation. More severe symptoms may include significant menstrual pain (dysmenorrhea), abdominal pain, migraine headaches, depression and irritability. Some women encounter premenstrual stress syndrome (PMS or premenstrual syndrome), a cyclic clinical entity. The list of symptoms experienced varies from person to person. Furthermore, within an individual, the severity of the symptoms may vary from cycle to cycle. ==The fertile window== While the length of the follicular phase — and consequently the length of the menstrual cycle — may vary, the luteal phase almost always takes 14 days. Sperm can survive for 3 to 4 days (possibly up to 7 days) inside a woman, so the most fertile period (the time with the highest likelihood of sexual intercourse leading to pregnancy) covers the time from some 5 days before ovulation until 1–2 days after ovulation. In a normal, four-week cycle, this corresponds to the second and the beginning of the third week of the cycle. Various natural family planning methods of birth control attempt to determine the precise time of ovulation in order to find the relatively fertile and the relatively infertile days in the cycle. People who have heard about the menstrual cycle and ovulation may commonly and mistakenly assume, for contraceptive purposes, that menstrual cycles always take a regular 28 days, and that ovulation always occurs 14 days after beginning of the menses. This assumption may lead to unintended pregnancies. Note too that not every bleeding event counts as a menstruation, and this can mislead people in their calculation of the fertile window. If a woman wants to conceive, the most fertile time occurs between 16 and 14 days prior to the expected menses. Many women use ovulation detection kits that detect the presence of the LH surge in the urine to indicate the most fertile time. Other ovulation detection systems rely on the subtle temperature shift that progesterone induces. Among women living closely together, the onsets of menstruation tend to synchronize somewhat. Researchers first described this phenomenon in 1971, and explained it by the action of pheromones in 1998 (Stern and McClintock 1998). == Hormonal control == Extreme intricacies regulate the menstrual cycle. For many years, researchers have argued over which regulatory system has ultimate control: the hypothalamus, the pituitary, or the ovary with its growing follicle; but all three systems have to interact. In any scenario, the growing follicle has a critical role: it matures the lining, provides the appropriate feed-back to the hypothalamus and pituitary, and modifies the mucus changes at the cervix. Two sex hormones play a role in the control of the menstrual cycle: estradiol and progesterone. While estrogen peaks twice, during follicular growth and during the luteal phase, progesterone remains virtually absent prior to ovulation, but becomes critical in the luteal phase and during pregnancy. Many tests for ovulation check for the presence of progesterone. These sex hormones come under the influence of the pituitary gland, and both FSH and LH play necessary roles. FSH stimulates immature follicles in the ovaries to grow. LH triggers ovulation. The gonadotropin-releasing hormone of the hypothalamus controls the pituitary, yet both the pituitary and the hypothalamus receive feed-back from the follicle. After ovulation the corpus luteum — which develops from the burst follicle and remains in the ovary — secretes both estradiol and progesterone. Only if pregnancy occurs do hormones appear in order to suspend the menstrual cycle, while production of estradiol and progesterone continues. Abnormal hormonal regulation leads to disturbance in the menstrual cycle. Some women with Neurology experience increased activity of their conditions at about the same time every month. 80 percent of women with epilepsy have more seizures than usual in the phase of their cycle when progresterone declines and estrogen increases. During times when progesterone is highest, Neuron Receptor (biochemistry) subtype delta was high. Nerve cells with more delta receptors are less likely to fire than cells with lower numbers of delta receptors. When estrogen levels are higher, the number of delta receptors decrease, increasing nerve cell activity, in turn increasing anxiety and seizure susceptability. (Maguire, et. al., 2005) ==Hidden ovulation== Unlike the case in other species, ovulation remains hidden in the human. The fact that a woman may sense her own ovulation while it remains indiscernible to others has sociobiology significance. In contrast, other species often signal receptivity. In this context, note that evidence suggests that women's preferences for men may change during their most fertile days, that is, before and shortly after ovulation. During this time, they will prefer different male scents, more masculine faces, and social presence and competitiveness in males considered as short-term partners. (Gangestad 2004) ==The ovary as an egg-bank== Evidence suggests that eggs are formed from germ cells early in fetal life. The number is reduced to an estimated 400,000 to 450,000 immature eggs residing in each ovary at puberty. The menstrual cycle, as a biologic event, allows for ovulation of one egg typically each month. Thus over her lifetime a woman will ovulate approximately 400 to 450 times. All the other eggs dissolve by a process called atresia. As a woman's total egg supply is formed in fetal life, to be ovulated decades later, it has been suggested that this long life-time may make the chromatin of eggs more vulnerable to division problems, breakage, and mutation than the chromatin of sperm, which are produced continuously during a man's reproductive life. This possibility is supported by the observation that conceptuses and infants of older mothers have higher rates of chromosome abnormalities than those of older fathers. == The anovulatory menstrual cycle== Not all menstruations result from an ovulatory menstrual cycle. In some women, follicular development may start but not complete, nevertheless estrogens will form and will stimulate the uterine lining. Sooner or later the uterus will shed this lining. As no ovulation and no progesterone involvement occurs, doctors call this type of bleeding an ''estrogen breakthrough bleeding'', and cannot always predict its duration or frequency. Anovulatory bleeding commonly occurs prior to menopause (premenopause) or in women with polycystic ovary syndrome. ==Cycle abnormalities== ===Frequency=== The "normal menstrual cycle" occurs every 28 days ± 7 days. Doctors term cycles with intervals of 21 days or fewer as ''polymenorrhea'' and, on the other hand, call cycles with intervals exceeding 35 days ''oligomenorrhea'' (or ''amenorrhea'' if intervals exceed 180 days). ===Flow=== The normal menstrual flow amounts to 50 ml ± 30 ml. Flow in excess of 80 ml (''hypermenorrhea'' or ''menorrhagia'') may stem from hormonal disturbance, uterine abnormalities, including uterine leiomyoma or cancer, and other causes. Doctors call the opposite phenomenon, of bleeding very little, ''hypomenorrhea''. ===Duration=== Prolonged bleeding (''metrorrhagia'', also ''meno-metrorrhagia'') does not show a clear interval pattern anymore. Dysfunctional uterine bleeding refers to hormonally-caused bleeding abnormalities, typically anovulation. All these bleeding abnormalities need medical attention. As pregnant patients may bleed, a pregnancy test forms part of the evaluation of abnormal bleeding. ==The birth control pill== Estrogens and progesterone-like hormones make up the main active ingredients of birth control pills. Typically they tend to mimic a menstrual cycle in appearance, but to suppress the critical event of the ovulatory cycle, namely ovulation. Normally, a woman takes hormone pills for 21 days, followed by 7 days of non-functional placebo sugar pills or no pills at all; then the cycle starts again. During the 7 placebo days, a ''withdrawal bleeding'' occurs; this differs from ordinary menstruation, and skipping the placebos and continuing with the next batch of hormone pills may suppress it. (Two main versions of the pill exist: ''monophasic'' and ''triphasic''. With triphasic pills, skipping of the placebos and continuing with the next month's dose can remove the pill's pregnancy protection.) In 2003 the United States Food and Drug Administration (FDA) approved low-dose monophasic birth control pills which induce withdrawal bleedings only every 3 months. == Etymology and the lunar month == The terms "menstruation" and "menses" come from the Latin ''mensis'' (month), which in turn relates to the Greek language ''mene'' (moon) and to the roots of the English words ''month'' and ''moon'' — reflecting the fact that the moon also takes close to 28 days to revolve around the Earth. (The synodical lunar month, the period between two new moons, lasts about 29 and a half days). Although some women's menstrual periods may conform to the lunar cycle, no necessary connection exists between lunar months and menstrual periods: women show considerable variation in the lengths of their menstrual cycle, and the length of the menstrual cycle differs in different animals (see below). == Sanitary issues== A whole industry has evolved to cater to menstruating women. Women commonly use sanitary towels (worn outside the vagina) or pads to prevent the soiling of clothes. Disposable ones are made wood pulp or synthetic products. Throughout history, washable cloths have been used; modern versions are produced made of cotton (often organic), on a parallel to washable diapers or nappies. Tampons (absorbent material inserted into the vagina) have become popular in the West over the last hundred years. A small number of women use reusable rubber menstrual cups. Pharmaceutical companies also provide products — commonly Non-steroidal anti-inflammatory drugs (NSAIDs) — to relieve menstrual cramps. ==Culture and menstruation == === Mysticism === Mysticism have sometimes elaborated "equivalencies", analogizing the waxing and waning of moon with influences on human menstruation. In this spiritual, moon goddess, or astrology context some women call menstruation their "moontime". Some ancient views also regarded menstruation as a cleansing of the body: compare bloodletting as a major medical treatment of pre-modern times. ===Religion=== Some religions consider women "unclean" during menstruation. ==== Islam on menstruation ==== The Islamic world considers a woman "not in a state to have intercourse" during menstruation. A verse from the Qur'an (with parenthesised interpolations by Dr. Muhammed Muhsin Khan) affirms this: ''"They ask you concerning menstruation. Say: that is an Adha (a harmful thing for a husband to have sexual intercourse with his wife while she is having her menses), therefore keep away from women during menses and go not unto them till they have purified (from menses and have taken a bath). And when they have purified themselves, then go in unto them as Allâh has ordained for you . Truly, Allâh loves those who turn unto Him in repentance and loves those who purify themselves (by taking a bath and cleaning and washing thoroughly their private parts, bodies, for their prayers, etc.)." '' (Al-Baqarah 2:222) See [http://63.175.194.25/index.php?ln=eng&ds=qa&lv=browse&QR=43028&dgn=4 an Islamic review] on the subject. ==== Judaism on menstruation ==== ''Main article: Niddah.'' A ritual exclusion applies to a woman while menstruating and for about a week thereafter, until she immerses herself in a mikvah (ritual bath). == Menstruation in other mammals == A regular menstrual cycle as described here only occurs in the great apes. Menstrual cycles vary in length from an average of 29 days in orangutan to an average of 37 days in chimpanzee. Females of other mammal species go through certain episodes called "estrus" or "heat" in each breeding season. During these times, ovulation occurs and females become receptive to mating, a fact advertised to males in some way. If no fertilization takes place, the uterus reabsorbs the endometrium: no menstrual bleeding occurs. Significant differences exist between the estrus and the menstrual cycle. ==References== * K. Stern and M. K. McClintock: "[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=9515961 Regulation of ovulation by human pheromones.]" ''Nature'', 392 (1998), pages 177 – 179. * Gangestad et al.: "[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15016293 Women's preferences for male behavioral displays change across the menstrual cycle.]" ''Psychological Science'', March 2004, vol. 15, no. 3, pages 203 - 207 * ==Notes== # "[http://www.4woman.gov/faq/menstru.htm#6 At what age does a girl get her first period?]," from ''Menstruation and the Menstrual Cycle'', National Women's Health Information Center (accessed June 11, 2005). # Ibid., "[http://www.4woman.gov/faq/menstru.htm#4 What is a typical menstrual period like?]" (accessed June 11, 2005). == External links == * Harry Finley: Online museum of menstruation and women's health, http://mum.org/ * Track your likely ovulatory date with this free [http://www.ovulation-calendar.net/ Ovulation Calendar] * Free Software to watch the menstrual cycle etc. http://www.natuerliche-verhuetung.de/en.htm * Leslie Botha-Williams, Women's Health Educator: A Woman's Guide to Understanding Her Hormone Cycle, http://www.holyhormones.com * [http://63.175.194.25/index.php?ln=eng&ds=qa&lv=browse&QR=43028&dgn=4 An Islamic answer for the ruling of women menstruating] == See also == * Amenorrhoea (or amenorrhea in US). * Zygote Reproductive system Gynecology
---- Are there typically two eggs produced in each cycle, one from each ovary, or just one? User:AxelBoldt 21:15 Jan 2, 2003 (UTC) : AFAIK, it's just one, and which ovary produces one is random. If there were two eggs, you'd get nonidentical twins. -- User:Tarquin 22:29 Jan 2, 2003 (UTC) ::Alternatively one ovary and then the other, I would say. Randomness would be too complex to implement ;-) --User: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. -- User: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." User: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? -- User:Someone else 06:22 Jan 8, 2003 (UTC)
:::Not confusing at all, thanks. User:AxelBoldt 17:51 Jan 8, 2003 (UTC)
::: Ditto. Great explanation, should be put in the article if not already -- User: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. --User: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! -- User: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".
*Actually it's mittelschmerz, literally "middle pain".
**Actually, it's Mittelschmerz. It's German language, so as a noun it must be capitalized. User:Matt gies 00:58, 30 May 2004 (UTC) Spelling but not capitalization are transferred to English. from your friendly Nitpicker.
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 -- User:Someone else 21:48 Jan 8, 2003 (UTC)
Do cows menstruate, I mean with blood and everything? User: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. user:cferrero
Same thing happened to me, definitely dogs have periods. This article is mistaken in that respect.
I've read that cats dont have a menopause -- but I don't know about the blood. -- User:Tarquin 21:53 Jan 8, 2003 (UTC)
I saw a cat having her period once. I'm really hoping she wasn't simply bleeding from there... Also, it was a pregnant cat, so perhaps that would actually dis-support the idea that she's menstruating.
:Male cats have a spine on their penis. I don't know if it's sharp enough to draw blood, but that's a possibility. 22:04, 22 Mar 2005 (UTC)
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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! :-) -- User: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.
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Does being on your period and having sex with no condom higher or lower the chances of getting pregnant?
:well, having sex with no condom definitely increases the chances of getting pregnant - not to mention increasing the chances of getting any of a number of unpleasant diseases - though I'm guessing that's not exactly the question? If the question is "are you somewhat less likely to get pregnant when you're menstruating than when you're not menstruating?" the answer is probably.... But a better question would be "Is having sex only when you're menstruating a reliable method of birth control?", to which the answer would be a most emphatic ''NO''. What do they call a woman who only has sex when she's "on her period"? Answer: "Mommy". -- User:Someone else 04:16, 1 Aug 2003 (UTC)
The previous paragraph (and the main article) both imply that it is possible to become pregnant while one is menstruating (say, in the first week, to be specific). But this is hard to understand, given the mechanism for the delivery and attachment of a fertilized egg. I have not been able to find references elsewhere on the Web to this idea. Can someone provide some reliable or credible justification? User:David spector 19:25, 29 May 2004 (UTC)
:Remember that menstruating simply means "bleeding from the uterus." The usual trigger is the drop in progesterone as the corpus luteum involutes, but there are other causes of hormone fluctuations, and in rare instances the egg may still be around to get fertilized and the zygote may implant despite waning progesterone levels. The reproductive system isn't quite like clockwork. Occasionally unusual things happen that beat the odds (like getting pregnant while on birth control pills). User:Alteripse 22:40, 29 May 2004 (UTC)
Okay, that makes sense. But still, regardless of hormone levels, how can the fertilized egg implant itself when the uteral lining is being shed? And if, by some miracle, it did, how would the egg grow without the nutrition that the lining provides? User:David spector 15:18, 31 May 2004 (UTC)
:I am not a gynecologist and havent taken the trouble to look this up but can guess at some possible scenarios. I suspect the most likely is that the zygote may sometimes not implant for a while despite continuing to develop. Alternatively, as must occur with ectopic pregnancy, the zygote may "implant" or attach or develop unattached without a hospitable endometrium-- in other words, implantation in the endometrium is not always necessary for progression of pregnancy. A third possibility would be that perhaps sometimes endometrial deciduation may be unsynchronized, uncoordinated, or incomplete so that there is enough for implantation. A third possible scenario would involve sperm hanging around much longer than usual, to catch the next egg that matures. A fourth would be premature. Perhaps I am still missing the right mechanism. More authoritative info would be welcome but I don't think we have a gynecologist on board. User:Alteripse 15:48, 31 May 2004 (UTC)
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"Worldwide, various cultures have experienced varying attitudes toward menstruation. The ?bleeding time? or ?moon time? has been viewed as "sacred" to an impure time, as well as everything in between. Contemporary society views this significant act of ?letting go? as an "unclean" end of the continuum, instead of viewing it as a part of a cyclic process of life and death, birth and rebirth.
Unfortunately, women have come to know and experience menstruation as the "the curse", something dirty and to be ashamed of; an attitude which society encourages and endorses?and which is constantly reinforced whenever broadcast media airs commercials for tampons and medications for PMS etc. Women are constantly being reminded in front of their partners, children, peers and co-workers that they are the weaker sex because of menstruation.
Menstruation, in fact is a time of great intuitive power. This phase is not a time to make changes; however, it is time to reflect on changes that need to be made in the next cycle. Persons who doubt the validity of such statements are encouraged to seek more information about women?s cycles as they are defined and written about by women who adhere to their cyclic nature. There is a wealth of information about this on the Internet. Women need to be aware that the less education that they have about their reproductive and hormonal systems, the more they are likely to be manipulated by an overzealous pharmaceutical industry that stands to profit greatly from their lack of knowledge."
1. This is not NPOV.
2. If reworded, this should rather go into the menstruation article.
3. The last paragraph is strawmanning propaganda for "natural medicines" or something like that. User:David.Monniaux 00:33, 4 Apr 2004 (UTC)
"
Menstruating women need to be aware that during the post-ovulatory phase of their cycle, their body systems are slowing down; as hormone levels are dropping, the immune system is also inhibited. Medications and other substances may have more of an adverse affect on women?s mental/emotional state than at other phases of the cycle. Since the body is slowing down, it is also important that women slow down mentally, emotionally and physically so as not to put undue stress on themselves. Menstruation is a time of ?letting go? ? not only of the uterine lining, but of mental and emotional issues; it is a time of release ? necessary so that a woman may start a new cycle after her menses has ended on all levels. Menstruation is part of a cyclic progression in women?s lives that honors life and all creation. Women are the human replicate of the Goddess on earth. Menstruating women are the font for the survival of humankind.
During the paramenstrum; pre-menstrual and bleeding phase, women will experience heightened sensitivity, are more aware, intuitive, psychic and powerful. If a woman does not abide with her body?s natural inclinations during this phase, she may experience adverse reactions; such as abdominal pain, migraine headache, depression and irritability."
Some more non NPOV + propaganda stuff. User:David.Monniaux 00:34, 4 Apr 2004 (UTC)
== Menstruation as a new Article ==
Anyhow, I recommand a new article named Menstruation to include all the cultural aspects as in
See "What links here": there are many items regarding the simple fact of "menstruation", pretty far away of a "cycle" -- User:Robodoc.at 10:58, 1 May 2004 (UTC)
== Islam & menstruation ==
Adha does literaly means 'a hurt'! Why did you change the text? Do you understand Arabic? User:Hadj 04:42, 12 Sep 2004 (UTC)
:I don't understand Arabic. I checked several English translations of the Quran and found that they contain different versions of that sentence, but none has the parenthesized inserts that your quote has. I think it is always important to cleanly distinguish between the literal text and an explanation, to avoid confusing the reader. Generally, if you put some text in double quotes in italics in its own paragraph and cite a Quran position afterwards, readers will assume that the paragraph is a literal quote from the Quran; the purpose of my edits was to avoid this mistaken assumption. I hope you can live with the current version of the article. Cheers, User:AxelBoldt 19:37, 12 Sep 2004 (UTC)
== What happens to the egg? ==
Hi. I just read the main article as well as some associated articles. It was unclear to me what happens to the egg that is travelling down the Fallopian tube but is not fertilized. Does it finishes its journey and ends up being eliminated along with the endometrium or does it stay in the tube and is somehow destroyed? As a matter of fact, I vaguely remember reading somewhere that the second hypothesis is what happens, and that the "reabsorption" of the egg by the female organism would be responsible for PMS. Is there any truth in this? You can probably tell that I know squad about the topic, but maybe this article or some of the associated ones could use some clarifying on what exactly happens to the unfertilized egg in its fruitless trip accross the Fallopian tube. Regards, User:Redux 19:32, 4 Oct 2004 (UTC)
== Changes 4/9/05 ==
I noticed that this is a featured article but hope it is ok to make some extensive changes. I tried to preserve all the information that had already been accumulated. In the section on 'Islam and menstruation' I removed a section that had been verbatim taken from another website, but the link to the website has been incorporated for reference.
User:Ekem 17:38, 9 Apr 2005 (UTC)
==stale eggs & mutation==
I removed the following recently added sentences here because they may not be correct and were expressed clumsily. I think the ideas may be good, and probably worth including but we need to make it more specific and verified.
''already "banked" in the ovary. As all these proto-eggs are present in the body from ((early in fetal development-- not birth)), and wait decades until they are used to create a new human life, this has implications for chromosomal damage. (this is a bit vague) Compare this to sperm, which are created fresh daily. A woman's exposure to radioactivity (including X-rays) and environmental toxin has a cumulative effect on her fertility, arguably more so than on that of men. (I have not seen direct evidence for this statement; is it just speculation or can you cite support?)''
It might be more precise and accurate to say, ''As a woman's total egg supply is formed in fetal life, to be ovulated decades later, it has been suggested that this long life-time may make the chromatin of eggs more vulnerable to division problems, breakage, and mutation than the chromatin of sperm, which are produced continuously during a man's reproductive life. This possibility is supported by the observation that conceptuses and infants of older mothers have higher rates of chromosome abnormalities than those of older fathers.''
I'm not so concerned about whose wording we use as that the facts are correct, and not just vaguely "arguable". I cannot think of any examples of environmental toxins causing damage to egg chromatin, and think it unlikely that radiation exposure plays any role in the age-related chromosome abnormalities. I am confident that the latter version is supportable but not so sure about the former. Further facts welcome. User:Alteripse 01:31, 2 Jun 2005 (UTC)
Your version sounds eminently sensible to me! I have no further facts to offer. From your technical language, i am sure you have far more detailed knowledge to draw on than I do. Please feel free to insert your changed sentences. Many thanks for your work. User:BrainyBabe 01:50, 2 Jun 2005 (UTC)
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==Least fertile time in menstrual cycle==
I would like to see a paragraph on the least fertile time in the menstrual cycle. The discussion always focusses on the most fertile time, never the least. Personally, this is important for me because I have sex with my girl friend only in the one or two days following full onset of menstruation, in the belief that that is the least fertile time. Surely some contributor to Wikipedia has access to some truly authoritative information on this important question. User:David spector 18:23, 3 Jun 2005 (UTC)
Hmmm, right. Normally, the fertility is around 14 days before the next periods. Or 14 days after the first day of past periods. The key is to see when the middle just is and to avoid this time area. You may note it by several manners
If you take temperature, it will be low for a certain number of days. Then, it will suddently go up by half a degree. Then stay up till the end of the cycle. The ovulation is on the day just before the temperature going up (the last day with low temperature). Of course, you can not guess that day. So, normally, you have 14 days of low temperature (beginning on first day of periods), followed by 14 days of higher temperature (ending on the day just before the periods or first day).
On the previous days before the temperature goes up, the white substance that gets out of vagina will get sticky. If there is no substance at all, sperm survive 24 hours. Not much. If there is a lot of substance, they survive up to 4 days. The ovule survives usually only 24 hours.
So if you make love at the beginning of the cycle, you should feel secure for *less* than a week after the periods stopped. I would say only 5-6 days. No more. As soon as there is white substance, protect yourself. Even if ovulation is 3-4 days later, the sperm might survive long enough, so be careful. So, only 5-6 days of secure time on a regular 28 days cycle. Day 5 till day 10.
Then, your girlfriend may note when the ovulation occur. It is the day just before the temperature going up. Usually, lots of white substance. Sometimes (in particular for those already mom), there is a tiny bit of blood loss. Sometimes, we also feel a bit of pain on one side for an hour or so. The uterus is also different, but most women do not want to check this. The best way to be sure when the ovulation occured is by temperature, but all the other information is good to confirm. After the ovulation, wait at least 3 days. At least. I'd say it would be okay to drop plastic stuff while she has been at least 4 days on higher temperature. If she is on a regular cycle, that should give you from day 19 possibly till day 27. There is normally always 14 days between ovulation and next periods. So, you have 7-8 good.
If she has an irregular cycle, always remember that the second part is the one fixed (always 14 days). The first part of the cycle is the one varying. If she is on a 3 weeks cycle, avoid making love just after the periods for at least 2 weeks without protection, or just make it only once just after the bleeding has stopped. If she is on a 5 weeks periods, yeah, champaign !!! you have 10-14 days fun.
Is that clear ?
User:Anthere 19:13, 3 Jun 2005 (UTC)
by the way, may I inquire why the article is protected ? Ant
== error - eggs are produced after birth ==
Not too long ago, it was proven that eggs do form after birth. (surprise!) I've lost the reference though, and I'm sure somebody will revert if I don't provide it. User:AlbertCahalan 18:39, 4 Jun 2005 (UTC)
You may be correct that someone has reported evidence of postnatal new egg development, but unless you can provide a reference that seems convincing, we should still go by the current consensus on the topic as reflected by the major textbooks on the topic. E.g. Johnson & Everitt, Essential Reproduction, Blackwell Science, 2000, page 14: ''...in the female all the oogonial germ cells cease dividing mitotically either before birth (human, cow, sheep, goat, mouse) or shortly thereafter (rat, pig, cat, rabbit, hamster) to enter into their first meiotic division, thereby becoming primary oocytes.... The consequence of this early termination of mitosis is that, by the time of birth, a woman has all the oocytes within her ovaries that she will ever have.'' We can update articles to reflect brand new research as soon as it can be verified. Don't act persecuted, just find a source. User:Alteripse 19:47, 4 Jun 2005 (UTC)
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Menstrual_cycle
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Menstrual cycle
The phrase menstrual cycle ( or ''period'') refers to the recurring physiology changes in a female's body that are under the control of the reproduction hormone system and necessary for reproduction. In women, menstrual cycles occur typically on a monthly basis between puberty and menopause. Besides humans, only great apes exhibit menstrual cycles, in contrast to the estrus cycle of most mammalian species. ==Overview== During the menstrual cycle, the sexually mature female body develops one egg (or occasionally two, which might result in non-identical twins) and releases it at the time of ovulation. The lining of the uterus, the endometrium, builds up in a synchronised fashion. After ovulation, this lining changes to prepare for potential implantation of the fertilized egg to establish a pregnancy. If fertilisation and pregnancy do not ensue, the uterus sheds the lining and a new menstrual cycle begins. The process of the shedding of the lining is called menstruation. Menstruation manifests itself to the outer world in the form of the menses ( also ''menstruum''): essentially part of the endometrium and blood products that pass out of the body through the vagina. Although this is commonly referred to as ''blood'', it is differs in composition from venous blood. Common usage refers to menstruation and menses as a period. This bleeding serves as a sign that pregnancy has not taken place. (However, this cannot be taken as certainty, as sometimes there is some bleeding in early pregnancy.) During the reproductive years, failure to menstruate may provide the first indication to a woman that she may have become pregnant. A woman might say that her "period is late" when an expected menstruation has not started and she might have become pregnant. Menstruation forms a normal part of a natural cyclic process occurring in healthy women between puberty and end of the reproductive years. The onset of menstruation, known as ''menarche'', occurs at an average age of 12, but can occur any time between the ages of 8 and 16. The last period, menopause, usually occurs between the ages of 45 and 55. Deviations from this pattern deserve medical attention. Amenorrhea refers to a prolonged absence of menses during the reproductive years of a woman for reasons other than pregnancy. For example, women with very low body fat, such as athletes, may cease to menstruate. The presence of menstruation does not prove that ovulation took place, and women who do not ovulate may have menstrual cycles. Those anovulatory cycles tend to take place less regularly and show greater variation in cycle length. == The normal menstrual cycle in humans == While cycle length may vary, 28 days is generally taken as representative of the normal ovulatory cycle in women. Convention uses the onset of menstrual bleeding to mark the beginning of the cycle, so the first day of bleeding is called "Cycle Day one". One can divide the menstrual cycle into four phases: ===Menstruation=== Menstruation lasts for a few days (usually 3 to 5 days, but anywhere from 2 to 7 days is considered normal) and involves the loss of about 1 E-5 m3 of blood (including shed endometrium). An enzyme called plasmin — contained in the endometrium — inhibits the blood from blood clotting. Because of this blood loss, women have higher dietary requirements for iron than do males — to prevent iron deficiency (medicine). Many women experience uterine cramps, also referred to as dysmenorrhea, during this time. A vast industry has grown to provide sanitary products to help women to manage their menses. ===Follicular phase=== Under the influence of follicle stimulating hormone (FSH) a number of follicles in the ovary start to grow and, in turn, produce estrogens, primarily estradiol. These estrogens initiate the development of a new layer of endometrium with the development of a typical histologic pattern termed the proliferative endometrium. The estrogens provide a negative feed-back loop to the pituitary gland and decrease the secretion of FSH. Inhibin secreted by the largest follicle also decreases FSH. Typically only the most advanced follicle (lead follicle) can develop further as it has more FSH receptors; the other follicles stop growing. This way, normally only one egg will mature in a given cycle. ===Ovulation=== When the follicle has matured, it secretes enough estradiol to trigger the acute release of luteinizing hormone (LH). In the 28-day cycle this LH surge starts around cycle day 12 and may last 48 hours. The release of LH matures the egg and weakens the wall of the follicle in the ovary. This process leads to ovulation: the release of the now mature ovum, the largest cell of the body (with a diameter of about 1 E-4 m). Which of the two ovaries — left or right — ovulates appears essentially random; no known left/right co-ordination exists. The Fallopian tube needs to capture the egg and provide the site for fertilization. A characteristic clear and stringy mucus exhibiting spinnbarkeit develops at the cervix, ready to accept sperm from intercourse. In some women, ovulation features a characteristic pain called ''Mittelschmerz'' which lasts for several hours. Many women perceive the vaginal and cervical mucus changes at ovulation, particularly if she is monitoring herself for signs of fertility. An unfertilised egg will disintegrate. ===Luteal phase=== After ovulation, the residual follicle transfoms into the corpus luteum under the support of the pituitary homones. This corpus luteum will produce progesterone in addition to estrogens for the next 2 weeks. Progesterone plays a vital role in converting the proliferative endometrium into a secretory lining receptive for implantation and supportive of the early pregnancy. It raises the body temperature slightly, thus woman who record their temperature on a daily basis will notice that they have entered the luteal phase. If fertilisation of an egg has occurred, it will travel as an early embryo through the tube to the uterine cavity and implant itself about 5 to 7 days after ovulation. Shortly after implantation, the growing embryo will signal its existence to the maternal system . One very early signal consists of human chorionic gonadotropin (hCG), a hormone that pregnancy tests can measure. This signal has an important role in maintaining the corpus luteum and enabling it to continue to produce progesterone. In the absence of a pregnancy and without hCG, the corpus luteum demises and inhibin and progesterone levels fall. This will set the stage for the next cycle. Progesterone withdrawal leads to menstrual shedding (''progesterone withdrawal bleeding''), and falling inhibin levels allow FSH levels to rise to raise a new crop of follicles. ==Menstrual symptoms== In many women, various unpleasant symptoms caused by the involved hormones and by cramping of the uterus can precede or accompany menstruation. More severe symptoms may include significant menstrual pain (dysmenorrhea), abdominal pain, migraine headaches, depression and irritability. Some women encounter premenstrual stress syndrome (PMS or premenstrual syndrome), a cyclic clinical entity. The list of symptoms experienced varies from person to person. Furthermore, within an individual, the severity of the symptoms may vary from cycle to cycle. ==The fertile window== While the length of the follicular phase — and consequently the length of the menstrual cycle — may vary, the luteal phase almost always takes 14 days. Sperm can survive for 3 to 4 days (possibly up to 7 days) inside a woman, so the most fertile period (the time with the highest likelihood of sexual intercourse leading to pregnancy) covers the time from some 5 days before ovulation until 1–2 days after ovulation. In a normal, four-week cycle, this corresponds to the second and the beginning of the third week of the cycle. Various natural family planning methods of birth control attempt to determine the precise time of ovulation in order to find the relatively fertile and the relatively infertile days in the cycle. People who have heard about the menstrual cycle and ovulation may commonly and mistakenly assume, for contraceptive purposes, that menstrual cycles always take a regular 28 days, and that ovulation always occurs 14 days after beginning of the menses. This assumption may lead to unintended pregnancies. Note too that not every bleeding event counts as a menstruation, and this can mislead people in their calculation of the fertile window. If a woman wants to conceive, the most fertile time occurs between 16 and 14 days prior to the expected menses. Many women use ovulation detection kits that detect the presence of the LH surge in the urine to indicate the most fertile time. Other ovulation detection systems rely on the subtle temperature shift that progesterone induces. Among women living closely together, the onsets of menstruation tend to synchronize somewhat. Researchers first described this phenomenon in 1971, and explained it by the action of pheromones in 1998 (Stern and McClintock 1998). == Hormonal control == Extreme intricacies regulate the menstrual cycle. For many years, researchers have argued over which regulatory system has ultimate control: the hypothalamus, the pituitary, or the ovary with its growing follicle; but all three systems have to interact. In any scenario, the growing follicle has a critical role: it matures the lining, provides the appropriate feed-back to the hypothalamus and pituitary, and modifies the mucus changes at the cervix. Two sex hormones play a role in the control of the menstrual cycle: estradiol and progesterone. While estrogen peaks twice, during follicular growth and during the luteal phase, progesterone remains virtually absent prior to ovulation, but becomes critical in the luteal phase and during pregnancy. Many tests for ovulation check for the presence of progesterone. These sex hormones come under the influence of the pituitary gland, and both FSH and LH play necessary roles. FSH stimulates immature follicles in the ovaries to grow. LH triggers ovulation. The gonadotropin-releasing hormone of the hypothalamus controls the pituitary, yet both the pituitary and the hypothalamus receive feed-back from the follicle. After ovulation the corpus luteum — which develops from the burst follicle and remains in the ovary — secretes both estradiol and progesterone. Only if pregnancy occurs do hormones appear in order to suspend the menstrual cycle, while production of estradiol and progesterone continues. Abnormal hormonal regulation leads to disturbance in the menstrual cycle. Some women with Neurology experience increased activity of their conditions at about the same time every month. 80 percent of women with epilepsy have more seizures than usual in the phase of their cycle when progresterone declines and estrogen increases. During times when progesterone is highest, Neuron Receptor (biochemistry) subtype delta was high. Nerve cells with more delta receptors are less likely to fire than cells with lower numbers of delta receptors. When estrogen levels are higher, the number of delta receptors decrease, increasing nerve cell activity, in turn increasing anxiety and seizure susceptability. (Maguire, et. al., 2005) ==Hidden ovulation== Unlike the case in other species, ovulation remains hidden in the human. The fact that a woman may sense her own ovulation while it remains indiscernible to others has sociobiology significance. In contrast, other species often signal receptivity. In this context, note that evidence suggests that women's preferences for men may change during their most fertile days, that is, before and shortly after ovulation. During this time, they will prefer different male scents, more masculine faces, and social presence and competitiveness in males considered as short-term partners. (Gangestad 2004) ==The ovary as an egg-bank== Evidence suggests that eggs are formed from germ cells early in fetal life. The number is reduced to an estimated 400,000 to 450,000 immature eggs residing in each ovary at puberty. The menstrual cycle, as a biologic event, allows for ovulation of one egg typically each month. Thus over her lifetime a woman will ovulate approximately 400 to 450 times. All the other eggs dissolve by a process called atresia. As a woman's total egg supply is formed in fetal life, to be ovulated decades later, it has been suggested that this long life-time may make the chromatin of eggs more vulnerable to division problems, breakage, and mutation than the chromatin of sperm, which are produced continuously during a man's reproductive life. This possibility is supported by the observation that conceptuses and infants of older mothers have higher rates of chromosome abnormalities than those of older fathers. == The anovulatory menstrual cycle== Not all menstruations result from an ovulatory menstrual cycle. In some women, follicular development may start but not complete, nevertheless estrogens will form and will stimulate the uterine lining. Sooner or later the uterus will shed this lining. As no ovulation and no progesterone involvement occurs, doctors call this type of bleeding an ''estrogen breakthrough bleeding'', and cannot always predict its duration or frequency. Anovulatory bleeding commonly occurs prior to menopause (premenopause) or in women with polycystic ovary syndrome. ==Cycle abnormalities== ===Frequency=== The "normal menstrual cycle" occurs every 28 days ± 7 days. Doctors term cycles with intervals of 21 days or fewer as ''polymenorrhea'' and, on the other hand, call cycles with intervals exceeding 35 days ''oligomenorrhea'' (or ''amenorrhea'' if intervals exceed 180 days). ===Flow=== The normal menstrual flow amounts to 50 ml ± 30 ml. Flow in excess of 80 ml (''hypermenorrhea'' or ''menorrhagia'') may stem from hormonal disturbance, uterine abnormalities, including uterine leiomyoma or cancer, and other causes. Doctors call the opposite phenomenon, of bleeding very little, ''hypomenorrhea''. ===Duration=== Prolonged bleeding (''metrorrhagia'', also ''meno-metrorrhagia'') does not show a clear interval pattern anymore. Dysfunctional uterine bleeding refers to hormonally-caused bleeding abnormalities, typically anovulation. All these bleeding abnormalities need medical attention. As pregnant patients may bleed, a pregnancy test forms part of the evaluation of abnormal bleeding. ==The birth control pill== Estrogens and progesterone-like hormones make up the main active ingredients of birth control pills. Typically they tend to mimic a menstrual cycle in appearance, but to suppress the critical event of the ovulatory cycle, namely ovulation. Normally, a woman takes hormone pills for 21 days, followed by 7 days of non-functional placebo sugar pills or no pills at all; then the cycle starts again. During the 7 placebo days, a ''withdrawal bleeding'' occurs; this differs from ordinary menstruation, and skipping the placebos and continuing with the next batch of hormone pills may suppress it. (Two main versions of the pill exist: ''monophasic'' and ''triphasic''. With triphasic pills, skipping of the placebos and continuing with the next month's dose can remove the pill's pregnancy protection.) In 2003 the United States Food and Drug Administration (FDA) approved low-dose monophasic birth control pills which induce withdrawal bleedings only every 3 months. == Etymology and the lunar month == The terms "menstruation" and "menses" come from the Latin ''mensis'' (month), which in turn relates to the Greek language ''mene'' (moon) and to the roots of the English words ''month'' and ''moon'' — reflecting the fact that the moon also takes close to 28 days to revolve around the Earth. (The synodical lunar month, the period between two new moons, lasts about 29 and a half days). Although some women's menstrual periods may conform to the lunar cycle, no necessary connection exists between lunar months and menstrual periods: women show considerable variation in the lengths of their menstrual cycle, and the length of the menstrual cycle differs in different animals (see below). == Sanitary issues== A whole industry has evolved to cater to menstruating women. Women commonly use sanitary towels (worn outside the vagina) or pads to prevent the soiling of clothes. Disposable ones are made wood pulp or synthetic products. Throughout history, washable cloths have been used; modern versions are produced made of cotton (often organic), on a parallel to washable diapers or nappies. Tampons (absorbent material inserted into the vagina) have become popular in the West over the last hundred years. A small number of women use reusable rubber menstrual cups. Pharmaceutical companies also provide products — commonly Non-steroidal anti-inflammatory drugs (NSAIDs) — to relieve menstrual cramps. ==Culture and menstruation == === Mysticism === Mysticism have sometimes elaborated "equivalencies", analogizing the waxing and waning of moon with influences on human menstruation. In this spiritual, moon goddess, or astrology context some women call menstruation their "moontime". Some ancient views also regarded menstruation as a cleansing of the body: compare bloodletting as a major medical treatment of pre-modern times. ===Religion=== Some religions consider women "unclean" during menstruation. ==== Islam on menstruation ==== The Islamic world considers a woman "not in a state to have intercourse" during menstruation. A verse from the Qur'an (with parenthesised interpolations by Dr. Muhammed Muhsin Khan) affirms this: ''"They ask you concerning menstruation. Say: that is an Adha (a harmful thing for a husband to have sexual intercourse with his wife while she is having her menses), therefore keep away from women during menses and go not unto them till they have purified (from menses and have taken a bath). And when they have purified themselves, then go in unto them as Allâh has ordained for you . Truly, Allâh loves those who turn unto Him in repentance and loves those who purify themselves (by taking a bath and cleaning and washing thoroughly their private parts, bodies, for their prayers, etc.)." '' (Al-Baqarah 2:222) See [http://63.175.194.25/index.php?ln=eng&ds=qa&lv=browse&QR=43028&dgn=4 an Islamic review] on the subject. ==== Judaism on menstruation ==== ''Main article: Niddah.'' A ritual exclusion applies to a woman while menstruating and for about a week thereafter, until she immerses herself in a mikvah (ritual bath). == Menstruation in other mammals == A regular menstrual cycle as described here only occurs in the great apes. Menstrual cycles vary in length from an average of 29 days in orangutan to an average of 37 days in chimpanzee. Females of other mammal species go through certain episodes called "estrus" or "heat" in each breeding season. During these times, ovulation occurs and females become receptive to mating, a fact advertised to males in some way. If no fertilization takes place, the uterus reabsorbs the endometrium: no menstrual bleeding occurs. Significant differences exist between the estrus and the menstrual cycle. ==References== * K. Stern and M. K. McClintock: "[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=9515961 Regulation of ovulation by human pheromones.]" ''Nature'', 392 (1998), pages 177 – 179. * Gangestad et al.: "[http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15016293 Women's preferences for male behavioral displays change across the menstrual cycle.]" ''Psychological Science'', March 2004, vol. 15, no. 3, pages 203 - 207 * ==Notes== # "[http://www.4woman.gov/faq/menstru.htm#6 At what age does a girl get her first period?]," from ''Menstruation and the Menstrual Cycle'', National Women's Health Information Center (accessed June 11, 2005). # Ibid., "[http://www.4woman.gov/faq/menstru.htm#4 What is a typical menstrual period like?]" (accessed June 11, 2005). == External links == * Harry Finley: Online museum of menstruation and women's health, http://mum.org/ * Track your likely ovulatory date with this free [http://www.ovulation-calendar.net/ Ovulation Calendar] * Free Software to watch the menstrual cycle etc. http://www.natuerliche-verhuetung.de/en.htm * Leslie Botha-Williams, Women's Health Educator: A Woman's Guide to Understanding Her Hormone Cycle, http://www.holyhormones.com * [http://63.175.194.25/index.php?ln=eng&ds=qa&lv=browse&QR=43028&dgn=4 An Islamic answer for the ruling of women menstruating] == See also == * Amenorrhoea (or amenorrhea in US). * Zygote Reproductive system Gynecology
Menstrual cycle
---- Are there typically two eggs produced in each cycle, one from each ovary, or just one? User:AxelBoldt 21:15 Jan 2, 2003 (UTC) : AFAIK, it's just one, and which ovary produces one is random. If there were two eggs, you'd get nonidentical twins. -- User:Tarquin 22:29 Jan 2, 2003 (UTC) ::Alternatively one ovary and then the other, I would say. Randomness would be too complex to implement ;-) --User: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. -- User: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." User: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?
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