Menopause , also known as climacteric , is the time in most women's lives when menstrual periods stop permanently, and they are no longer able to bear children. Menopause usually occurs between 49 and 52 years. Medical professionals often define menopause occurring when a woman does not experience vaginal bleeding for a year. This can also be defined by a decrease in hormone production by the ovaries. In those who have had surgery to remove their uterus but still have an ovary, menopause can be seen to have occurred at the time of surgery or when their hormone levels drop. After removal of the uterus, symptoms usually occur earlier, averaging 45 years.
Before menopause, the woman's period usually becomes irregular, meaning that the period may be longer or shorter in duration or lighter or more severe in the amount of flow. During this time, women often experience hot flashes; This usually lasts from 30 seconds to ten minutes and may be associated with chills, sweating, and reddening of the skin. Hot flashes often stop happening after a year or two. Other symptoms may include vaginal dryness, sleeping difficulties, and mood swings. The severity of symptoms varies between women. While menopause is often thought to be associated with increased heart disease, it is mainly due to age and has no direct relationship to menopause. In some women, present problems such as endometriosis or painful periods will improve after menopause.
Menopause is usually a natural change. It could happen earlier in those who smoke tobacco. Other causes include surgery that lifts both ovaries or some type of chemotherapy. At the physiological level, menopause occurs due to decreased ovarian production of estrogen and progesterone hormones. Although not usually necessary, the diagnosis of menopause can be confirmed by measuring hormone levels in the blood or urine. Menopause is the opposite of menarche, a time when a girl's period begins.
Special care is usually not necessary. Some symptoms, however, can be corrected with treatment. In connection with hot flash, avoiding smoking, caffeine, and alcohol is often recommended. Sleeping in a cool room and using a fan can help. The following medications may be helpful: menopausal hormone therapy (MHT), clonidine, gabapentin, or selective serotonin reuptake inhibitors. Exercise can help overcome sleep problems. While MHT is routinely prescribed, it is now only recommended to those with significant symptoms, as there are concerns about side effects. High-quality evidence for the effectiveness of alternative medicine has not been found. There is tentative evidence for phytoestrogens.
Video Menopause
Signs and symptoms
During early menopause transition, the menstrual cycle remains orderly but the interval between cycles begins to elongate. Hormonal levels begin to fluctuate. Ovulation may not occur in every cycle.
The date of the last menstrual period is usually taken as a point when menopause has occurred. During menopausal transition and after menopause, women may experience various symptoms.
Vagina and uterus
During the transition to menopause, the menstrual pattern may show shorter cycles (2-7 days); Longer cycles are still possible. There may be irregular bleeding (lighter, heavier, spotting). Dysfunctional uterine bleeding is often experienced by women approaching menopause due to the hormonal changes that accompany the transition of menopause. Spots or bleeding may only be associated with vaginal atrophy, benign pain (polyps or lesions), or possibly functional endometrial responses. The European Menopausal Society and Andropause have issued guidelines for endometrial assessment, which is usually the main source of spotting or bleeding.
In post-menopausal women, however, any genital bleeding is an alarming symptom that requires proper research to rule out the possibility of malignant disease.
Symptoms that may arise during menopause and continue through postmenopause include:
- painful intercourse
- vaginal dryness
- atrophic vaginitis - depletion of the vulva, vaginal, cervical, and outer urinary tract, together with large shrinkage and loss in the elasticity of all external and internal genital areas.
Other physical
Other physical symptoms of menopause include energy deficiency, joint pain, stiffness, backache, breast augmentation, breast tenderness, palpitations, headache, dizziness, dryness, itchy skin, thinning, tingling skin, weight loss, urinary incontinence, urinary urgency, severed sleep, heavy night sweats, hot flashes.
Psychological
Psychological symptoms include anxiety, poor memory, inability to concentrate, depressed mood, irritability, mood swings, lack of interest in sexual activity.
Long-term effects
Menopause conferred:
- Possible increased risk of atherosclerosis. The risk of acute myocardial infarction and other cardiovascular disease increases sharply after menopause, but the risks can be reduced by managing risk factors, such as tobacco smoking, hypertension, elevated blood lipids and weight.
- Increased risk of osteopenia, osteoporosis, and decreased lung function accelerated.
Women who experience menopause before the age of 45 years have an increased risk of heart disease, death, and impaired lung function.
Maps Menopause
Cause
Menopause can be induced or occurs naturally. Menopause caused as a result of medical treatments such as chemotherapy, radiotherapy, oophorectomy, or tubal ligation complications, hysterectomy, unilateral salpingo-oophorectomy or leuprorelin.
Age
Menopause usually occurs between 49 and 52 years. In India and the Philippines, the average age of natural menopause is much earlier, ie 44 years.
In rare cases, the female ovary stops working at a very young age, from the age of puberty to the age of 40 years. This is known as premature ovarian failure and affects 1 to 2% of women at age 40.
Undiagnosed and untreated celiac disease is a risk factor for early menopause. Celiac disease may present with some non-gastrointestinal symptoms, in the absence of gastrointestinal symptoms, and most cases pass timely and undiagnosed recognition, leading to the risk of long-term complications. A tight gluten-free diet reduces risk. Women with early diagnosis and treatment of celiac disease present a normal duration of fertile life.
Women who had undergone hysterectomy with ovarian conservation underwent menopause on average 3.7 years earlier than expected. Other factors that can lead to premature menopause (usually 1 to 3 years earlier) are smoking or becoming very thin.
Premature ovarian failure
Ovarian premature failure (POF) is the cessation of ovarian function before age 40 years. It is diagnosed or confirmed by follicular follicle (FSH) and high blood luteinizing (LH) hormones at least three times at least four weeks.
The causes of known ovarian premature failure include autoimmune disorders, thyroid disease, diabetes mellitus, chemotherapy, carriers of the fragile X syndrome gene, and radiotherapy. However, in about 50-80% of cases of spontaneous premature ovarian failure, the cause is unknown, that is, generally idiopathic.
Women who have functional disorders that affect the reproductive system (eg, endometriosis, polycystic ovary syndrome, reproductive organ cancers) may enter menopause at a younger age than in normal time. Functional disorders often significantly speed up the menopause process.
Early menopause can be attributed to smoking, higher body mass index, race and ethnic factors, disease, and surgical removal of the ovaries, with or without removal of the uterus.
Premature menopause rates have been found to be significantly higher in fraternal and identical twins; about 5% of twins reach menopause before the age of 40. The reason for this is not fully understood. Ovarian tissue transplantation between identical twins has successfully restored fertility.
Surgical menopause
Menopause can be induced by surgery by bilateral oophorectomy (removal of the ovaries), which is often, but not always, performed simultaneously with the removal of the Fallopian tubes (salpingo-oophorectomy) and the uterus (hysterectomy). The termination of menstruation as a result of removal of the ovaries is called "surgical menopause". A sudden and complete drop in hormone levels usually results in extreme withdrawal symptoms such as hot flashes, etc.
The removal of the uterus without ovaries does not directly result in menopause, although this type of pelvic surgery can often lead to somewhat earlier menopause, possibly due to impaired blood supply to the ovaries.
Mechanism
The transition of menopause, and postmenopause itself, is a natural change, usually not a state of disease or disorder. The main causes of this transition are natural depletion and aging of limited oocyte counts (ovarian reserve). This process is sometimes accelerated by other conditions and is known to occur earlier after various gynecological procedures such as hysterectomy (with and without ovariectomy), endometrial ablation and uterine artery embolization. The depletion of ovarian reserves causes increased hormone-stimulating hormone (FSH) and luteinizing hormone (LH) levels because there are fewer oocytes and follicles responding to these hormones and producing estrogen.
Transitions have varying degrees of effect.
The stages of menopausal transition have been classified according to the pattern of bleeding reported by a woman, supported by changes in the level of the pituitary follicle stimulating hormone (FSH).
In younger women, during the normal menstrual cycle the ovaries produce estradiol, testosterone and progesterone in a cycle pattern under the control of FSH and luteinising hormone (LH) both produced by the pituitary gland. During perimenopause (before menopause), estradiol levels and patterns of production remain relatively unchanged or may increase compared with young women, but the cycle becomes shorter or irregular. The observed increase in estrogen is thought to be a response to elevated levels of FSH which, in turn, is hypothesized to be due to a decrease in feedback by inhibin. Similarly, decreased inhibin feedback after hysterectomy was hypothesized to contribute to increased ovarian stimulation and early menopause.
Menopausal transition is characterized by marked, and often dramatic, variations in FSH and estradiol levels. Therefore, measurement of these hormones is not considered a reliable guide to a woman's proper menopausal status.
Menopause occurs due to a sharp decline in estradiol and progesterone production by the ovaries. After menopause, estrogen continues to be produced mostly by aromatase in fatty tissue and is produced in small amounts in many other tissues such as the ovaries, bones, blood vessels, and brain where it acts locally. The substantial fall in the circulation of estradiol levels during menopause affects many tissues, from the brain to the skin.
In contrast to the sudden decrease in estradiol during menopause, total and free testosterone levels, as well as dehydroepiandrosterone sulfate (DHEAS) and androstenedione appear to decrease more or less steadily with age. The effect of natural menopause on circulating androgen levels has not been observed. Thus, the specific tissue effects of natural menopause can not be attributed to loss of androgenic hormone production.
Hot flashes and other vasomotor symptoms accompany the transition of menopause. While many sources continue to claim that hot flashes during a menopausal transition are caused by low estrogen levels, this statement proved wrong in 1935 and, in many cases, hot flashes were observed even though estrogen levels increased. The exact cause of these symptoms is not yet understood, the possible factor being considered is the higher and erratic variation of the estradiol levels during the cycle, an increase in FSH levels that may indicate hypothalamic dysregulation may be due to feedback lost by inhibin. It has also been observed that vasomotor symptoms differ during the early perimenopause and the transition of menopause is delayed and they may be caused by different mechanisms.
Long-term effects of menopause may include osteoporosis, vaginal atrophy as well as changes in metabolic profile resulting in heart risk.
Ovarian aging
Decreased inhibin feedback after hysterectomy is hypothesized to contribute to increased ovarian stimulation and early menopause. Accelerated aging of the ovaries has been observed after endometrial ablation. Although it is difficult to prove that this operation is causative, it has been hypothesized that the endometrium may produce endocrine factors that contribute to endocrine feedback and regulation of ovarian stimulation. Elimination of these factors contributes to faster depletion of ovarian reserves. The reduced blood supply to the ovaries that may occur as a consequence of arterial embolization of the hysterectomy and uterine has been hypothesized to contribute to this effect.
Damaged DNA repair mechanisms can contribute to the depletion of ovarian reserves early during aging. As women age, double-strand breaks accumulate in their primordial follicle DNA. The primordial follicle is an immature primary oocyte surrounded by a layer of granulosa cells. The enzyme system is present in oocytes that usually accurately repair the DNA damage of multiple strands. This repair system is called "homologous recombination repair", and it is especially effective during meiosis. Meiosis is a common process in which germ cells form in all sexual eukaryotes; seems to be an adaptation to efficiently remove damage to germ line DNA. (See Meiosis.)
The primary human oocyte is present at the intermediate stage of meiosis, called prophase I (see Oogenesis). The expression of four key DNA repair genes required for improvement of homologic recombination during meiosis (BRCA1, MRE11, Rad51, and ATM) decreased with age in oocytes. This age-related setback in ability to repair DNA double-strand damage can explain the accumulation of this damage, which then contributes to the depletion of ovarian reserves.
Diagnosis
One way to assess the impact on women of some of these menopausal effects is the Greene's climacteric scale questionnaire, Cervantes scale and Menopause scales.
Premenopause
Premenopause is a term used to indicate the years leading up to the last period, when the levels of the reproductive hormone become more variable and lower, and the effects of hormone withdrawal are present. Premenopause begins some time before the monthly cycle becomes irregular in time.
Perimenopause
The term "perimenopause", which literally means "around menopause" refers to the menopausal transition years, the time before and after the date of the final episode of the flow. According to the American Menopause Society of North America, this transition can last for four to eight years. The Menstrual Cycle and Ovulation Research Center describes it as a six to ten year phase that ends 12 months after the last menstrual period.
During perimenopause, estrogen levels are on average about 20-30% higher than during premenopausal, often with extensive fluctuations. This fluctuation causes many physical changes during perimenopause as well as menopause. Some of these changes are hot flashes, night sweats, difficulty sleeping, vaginal or atrophic dryness, incontinence, osteoporosis, and heart disease. During this period, fertility decreases but is not considered to reach zero until the official date of menopause. The official date is determined retroactively, after 12 months elapsed after the last appearance of menstrual blood.
Menopausal transition usually begins between 40 and 50 years (mean 47.5). Perimenopausal duration may be up to eight years. Women will often, but not always, initiate this transition (perimenopause and menopause) at the same time as their mother.
In some women, menopause can cause a sense of loss associated with the end of fertility. In addition, these changes often occur when other stressors may exist in the life of a woman:
- Caring, and/or death, elderly parents
- The nest syndrome is empty when children leave home
- The birth of the grandchildren, who place "middle-age" people into the new category of "parents" (especially in cultures where the older is underrated)
Several studies have shown that melatonin supplementation in perimenopausal women can improve thyroid function and gonadotropin levels, as well as restore fertility and menstruation as well as prevent depression associated with menopause.
Postmenopause
The term "postmenopausal" describes women who have not experienced menstrual flow for at least 12 months, assuming that they have a uterus and are not pregnant or breastfeeding. In women without a uterus, menopause or postmenopausal can be identified by blood tests that show very high FSH levels. So postmenopausal is the time in a woman's life that occurs after her last period or, more accurately, after the point when her ovaries become inactive.
The reason for this delay in postmenopausal states is that the period is usually uncertain at this point. Therefore, it takes a long time to ensure that the cycling has stopped. At this point a woman is considered infertile; However, the possibility of pregnancy is usually very low (but not quite zero) for several years before this point is reached.
Female reproductive hormone levels continue to decline and fluctuate for some time to post menopause, so the effects of hormone withdrawal like hot flashes may take several years to disappear.
Flows that resemble periods during postmenopause, even spotting, may be signs of endometrial cancer.
Management
Perimenopause is the natural stage of life. It is not a disease or disorder. Therefore, it does not automatically require medical care. However, in cases where the physical, mental, and emotional effects of perimenopause are strong enough to interfere with the lives of women who experience them, palliative medical therapy is sometimes appropriate.
Hormone replacement therapy
In the context of menopause, hormone replacement therapy (HRT) is the use of estrogen in women without uterine and estrogen plus progestin in women who have uterus intact.
HRT may make sense for the treatment of menopausal symptoms, such as hot flashes. This is the most effective treatment option, especially when sent as a skin patch. Its use, however, appears to increase the risk of stroke and blood clotting. When used for menopausal symptoms, some recommend to use as short as possible and with the lowest possible dose. Evidence to support long-term but poor use.
It also appears to be effective for preventing bone loss and osteoporosis fracture, but is generally recommended only for women at significant risk for other inappropriate therapies.
HRT may be unsuitable for some women, including those at high risk for cardiovascular disease, increased risk of thromboembolic disease (such as those with obesity or a history of venous thrombosis) or an increased risk of some cancers. There are some concerns that these treatments increase the risk of breast cancer.
Adding testosterone to hormone therapy has a positive effect on sexual function in postmenopausal women, although it may be accompanied by hair growth, acne and a reduction in high-density lipoprotein (HDL) cholesterol. These side effects differ depending on the dosage and the method of using testosterone.
Selective estrogen receptor modulators
SERMs are a category of drugs, either synthetically produced or derived from botanical sources, which act selectively as agonists or antagonists at estrogen receptors throughout the body. The most commonly prescribed SERMs are raloxifene and tamoxifen. Raloxifene shows estrogen agonist activity in bone and lipids, and antagonistic activity in the breast and endometrium. Tamoxifen is widely used for the treatment of hormone-sensitive breast cancer. Raloxifene prevents vertebral fractures in postmenopausal women, osteoporosis and reduces the risk of invasive breast cancer.
Other drugs
Some SSRIs and SNRIs seem to provide assistance. Low-dose paroxetine has been FDA approved for moderate-to-severe vasomotor symptoms associated with menopause. They may, however, be associated with sleep problems.
Gabapentin or clonidine may help but do not work as well as hormone therapy. Clonidine may be associated with constipation and sleep problems.
Alternative medicine
There is no evidence of the consistent benefits of alternative therapies for menopausal symptoms despite their popularity. The effect of soy isoflavones on menopausal symptoms is promising to reduce hot flash and vaginal dryness. The evidence does not support the benefits of phytoestrogens such as coumestrol, femarelle, or black cohosh non-phytoestrogens. There is no evidence to support the efficacy of acupuncture as the management of menopausal symptoms. In 2011 there was no support for herbal or dietary supplements in the prevention or treatment of mental changes that occur around menopause. The 2016 Cochrane review found no evidence to show the difference between Chinese herbal medicine and placebo for vasomotor symptoms.
Other therapies
- Lack of lubrication is a common problem during and after perimenopause. Vaginal moisturizers can help women with overall drought, and lubricants can help with any lubrication difficulties that may be present during intercourse. It should be pointed out that moisturizers and lubricants are different products for different problems: some women complain that their genitals are dry uncomfortably all the time, and they may be better with moisturizers. Those who only need lubrication should use it only during sexual intercourse.
- Low-dose estrogen-prescribing products such as estrogen creams are generally a safe way to use estrogen topically, to help with vaginal and drought thinning problems (see vaginal atrophy) while only slightly increasing estrogen levels in the bloodstream.
- In terms of managing hot flashes, lifestyle measures such as drinking cold liquids, staying in a cool room, using fans, removing excess clothing, and avoiding hot flash triggers such as hot drinks, spicy food, etc., can partially complete (or even eliminated) drug use for some women.
- Individual counseling or support groups can sometimes help to deal with the sad, depressed, anxious, or confused feelings that women may encounter as they pass what can happen during a very challenging transition.
- Osteoporosis can be minimized by quitting smoking, sufficient vitamin D intake, and weight-bearing exercise regularly. Alendronate bisphosphate drugs can reduce the risk of fractures, in women who have bone loss and previous fractures and less for those with only osteoporosis.
Society and culture
The cultural context in which a woman lives can have a significant impact on the way she experiences a menopausal transition. Menopause has been described as a subjective experience, with social and cultural factors playing an important role in how menopause is experienced and perceived.
In the United States, social location affects how women perceive menopause and its associated biological effects. Research shows that whether a woman views menopause as a medical problem or a change of life is expected to be correlated with her socioeconomic status. The paradigm in which a woman considers menopause affects the way she sees it: Women who understand menopause as a medical condition judge significantly more negatively than those who see it as a life transition or symbol of aging.
Ethnicity and geography play a role in the experience of menopause. American women of different ethnicity report different types of menopausal effects. One large study found Caucasian women are likely to report what is sometimes described as psychosomatic symptoms, while African-American women are more likely to report vasomotor symptoms.
It seems that Japanese women experience menopausal effects, or konenki , in a way different from American women. Japanese women report lower levels of hot flash and night sweats; this can be attributed to various factors, both biologically and socially. Historically, konenki was associated with a wealthy middle-class housewife in Japan, that is, it was a "luxurious disease" that women from traditional rural households, between generations did not report. Menopause in Japan is seen as a symptom of the inevitable aging process, not a "revolutionary transition", or "disease of deficiency" that requires management.
In Japanese culture, the reporting of vasomotor symptoms has increased, with a study conducted by Melissa Melby in 2005 found that of 140 Japanese participants, hot flashes were prevalent at 22.1%. This is almost twice that of the previous 20 years. While the exact cause for this is unknown, the possible contributing factors include significant dietary changes, improved middle-aged woman's medicalization and increased media attention on the subject. However, reporting of vasomotor symptoms is still much lower than North America.
Moreover, while most women in the United States seem to have a negative view of menopause as a time of deterioration or decline, some research seems to indicate that women from some Asian cultures have an understanding of menopause that focuses on a sense of freedom and celebrates freedom from the risks of pregnancy. Postmenopausal Indian women can enter Hindu temples and participate in rituals, marking it as a celebration to reach age of wisdom and experience.
In contrast to this conclusion, one study shows that many American women "experience today as one of liberation and self-actualization".
In general, women raised in the Western world or developed countries in Asia live long enough that one-third of their lives are spent in post-menopause. For some women, the transition of menopause is a major life change, similar to menarche in the magnitude of its social and psychological significance. Although the significance of the changes surrounding the menarche are well known, in countries such as the United States, the social and psychological consequences of menopausal transition are often ignored or underestimated.
Etymology
Menopause literally means "end of monthly cycle" (the end of monthly or menstrual period), from the Greek word pausis ("pause") and m? N ("month"). This is a medical line; the Greek word for menstruation is different. In Ancient Greek, menstruation is described in plural form, ta emm? Nia , ("the monthlies"), and her modern descendants have been trimmed into ta emm? Na . The modern Greek medical term is Emperopausis in Katharevousa or europausi in Demotic Greek.
The word "menopause" was created specifically for human women, where the end of fertility is traditionally demonstrated by the permanent cessation of monthly menstruation. However, menopause exists in some other animals, many of whom have no monthly menstruation; in this case, the term means a natural ending to fertility that occurs before the end of a natural lifetime.
Evolutionary thinking
Various theories have suggested that efforts to suggest the benefits of evolution for human species stem from the cessation of women's reproductive capabilities before their natural end of life. Explanations can be categorized as adaptive and non-adaptive:
The non-adaptive hypothesis
The high cost of investing women in offspring can cause physiological damage that strengthens vulnerability to infertility. This hypothesis shows the reproductive age in humans has been optimized, but has proven to be more difficult in women and thus their reproductive range is shorter. If this hypothesis is true, however, the age at menopause should be negatively correlated with the reproductive effort and the available data does not support this.
The recent increase in women's longevity due to improvements in living standards and social care has also been suggested. Difficult for selection, however, to support the help for descendants of parents and grandparents. Regardless of the standard of living, the adaptive response is limited by physiological mechanisms. In other words, aging is engineered and regulated by certain genes.
Adaptive hypotheses
"Survival of the fittest" hypothesis
This hypothesis shows that younger mothers and descendants under their care will be better in a difficult environment and predators because younger mothers will become stronger and more agile in providing protection and sustenance for themselves and breastfed babies. The various biological factors associated with menopause have the effect of male members of the species who invest their efforts with the most potential female pairs. One problem with this hypothesis is that we would expect to see the menopause exhibited in the animal kingdom.
Mother hypothesis
The maternal hypothesis suggests that menopause is chosen for humans because of the long period of progression of human offspring and the high cost of reproduction so that mothers benefit in reproductive fitness by directing their efforts from new offspring with low survival opportunities for existing children with survival opportunities higher.
Hypothesis of ancestors
Grandma's hypothesis shows that menopause is chosen for humans because it promotes the survival of grandchildren. According to this hypothesis, post-reproductive women feed and care for children, adult nursing daughters, and grandchildren whose mothers have weaned them. The human baby needs a large, stable supply of glucose to feed the growing brain. In infants in the first year of life, the brain consumes 60% of all calories, so babies and their mothers need a reliable supply of food. Some evidence suggests that hunters account for less than half the total food budget for most hunter-gatherer societies, and often less than half, so that foraging ancestors can contribute substantially to the survival of grandchildren at a time when mothers and fathers can not collect enough food for all their children. In general, selection operates most strongly during times of famine or other preoccupation. So, although grandmothers may not be needed during good times, many grandchildren can not survive without them during the famine. Arguably, however, there is no strong consensus about the evolutionary advantage (or neutrality) of menopause against the survival of species in the evolutionary past.
Indeed, the analysis of historical data found that the length of life of a post-reproductive woman is reflected in the reproductive success of her offspring and the survival of her grandchildren. Interestingly, other studies found a comparative effect but only in paternal-maternal grandmothers who had a detrimental effect on infant mortality (possibly because of paternal uncertainty). Different aid strategies for maternal and paternal grandmothers have also been demonstrated. The maternal grandmother concentrates on hereditary survival, while the paternal grandmother increases the birth rate.
Some people believe that the problem associated with the grandmother's hypothesis is that it requires the history of female courtesy while in the present the majority of hunter-gatherer societies are patriarchal. However, there is disagreement split along the ideological line of whether patrilineality will exist before modern times. Some believe variations in the mother, or grandmothers' effects fail to explain longevity with spermatogenesis sustained in men (the oldest verified father was 94 years old, 35 years old beyond the documented oldest birth attributed to women). In particular, the time of survival through menopause is approximately equal to the time of maturation for a human child. That the presence of a mother can help the survival of a developing child, while the absence of an unknown father may not affect survival, can explain father's fertility near the end of his father's lifetime. A man with no certainty that his sons may be trying to be the father of additional children, with the support of small but existing children. Notice the existence of middle-aged father support this. Some argue that maternal and grandmother hypotheses fail to explain the detrimental effects of loss of ovarian follicle activity, such as osteoporosis, osteoarthritis, Alzheimer's disease and coronary artery disease.
The theories discussed above assume that evolution is directly selected for menopause. Another theory suggests that menopause is a byproduct of evolutionary selection for follicular atresia, a factor that causes menopause. Menopause results from having too few ovarian follicles to produce enough estrogen to maintain the pituitary-pituitary-pituitary loop, which results in menstrual cessation and early menopause. Female humans are born with about one million oocytes, and about 400 missing oocytes due to ovulation throughout life.
Other animals
Menopause in the animal kingdom seems uncommon, but the presence of this phenomenon in different species has not been thoroughly researched. Life history shows varying degrees of aging; rapidly senescing organisms (eg, Pacific salmon and annual crops) have no post-reproductive life stages. Gradual aging is demonstrated by all the history of the life of placental mammals.
Menopause has been observed in several species of nonhuman primates, including rhesus monkeys and chimpanzees. Menopause has also been reported in a variety of other vertebrate species including elephants, short fins, whales and other cetaceans, guppy, platyfish, budgerigar, rat and lab rats, and opossum. However, with the exception of the short-finned pilot whales, such examples tend to stem from captured individuals, and thus they do not necessarily represent what happens to natural populations in the wild.
Dogs do not experience menopause; The estrus cycle of the dog becomes irregular and sparse. Although older female dogs are not considered as good candidates for breeding, their offspring have been produced by older animals. Similar observations have been made on cats.
See also
- Folliculogenesis
- Ovarian reserve
- European Menopausal Society and Andropause
- Pregnancy above the age of 50
- Hypothesis of ancestors
References
External links
- Menopause: MedlinePlus
- Menopause dan Menopause Treatments
Source of the article : Wikipedia
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