Menarche ( mi- NAR -kee ; Greek: ??? m? n "month" ? "early") is the first menstrual cycle, or first menstrual bleeding, in a female human. From a social and medical perspective, it is often regarded as a major female puberty event, as this signifies the possibility of fertility.
Girls experience menarche at different ages. Menarche time is influenced by female biology, as well as genetic and environmental factors, especially nutritional factors. The average age of menarche has declined over the last century, but the magnitude of the decline and responsible factors remains the subject of contention. The average age of menarche in the world is very difficult to estimate accurately, and it varies significantly according to geographical, racial, ethnic and other characteristics. Various estimates have placed it at 13. Some estimates indicate that median menarche median age worldwide is 14, and that there is a later age of onset in Asian populations compared with the West. The average age of menarche is about 12.5 years in the United States, 12.72 in Canada, and 12.9 in the UK. A study of girls in Istanbul, Turkey, found the average age at menarche to 12.74 years.
Video Menarche
Physiology
Puberty
Menarche is the culmination of a series of physiological and anatomic processes of puberty:
- Achievement of adequate body mass (usually 17% body fat).
- Disinhibition of the GnRH pulse generator in the arcuate nucleus of the hypothalamus.
- Secretion of estrogen by the ovaries in response to pituitary hormones.
- During an interval of about 2 to 3 years, estrogen stimulates uterine growth (such as height growth, breast growth, pelvic widening, and enhancement of regional adipose tissue).
- Estrogen stimulates growth and vascularization of the endometrium, the uterine wall.
- Fluctuations in hormone levels can cause changes in the adequacy of blood supply to the endometrium.
- The death of some endometrial tissue due to hormonal fluctuations or blood supply leads to deciduation, the decay of parts of the lining with some blood flow from the vagina.
There is no specific hormonal signal for known menarche; menarche as a discrete event is considered a relatively coincidental result of the gradual endometrial thickening caused by increased puberty estrogen but fluctuates.
The menstruum , or flow, consists of a combination of fresh blood and clumped with endometrial tissue. The early flow of menarche is usually brighter than a mature menstrual flow. Often the numbers are limited in number and may be very short, even one instance of "spotting". Like other menstruation, menarche can be accompanied by abdominal cramps.
Relationship to fertility
In most women, menarche does not mean that ovulation has occurred. In postmenarchal girls, about 80% of cycles undergo anovulation in the first year after menarche, 50% in the third year and 10% in the sixth year. Ordinary ovulation is usually indicated by predictable and consistent intervals between menstruation, predictable and consistent duration of menstruation, and predictable and consistent flow patterns (eg, weight or cramp). Continuing ovulation usually requires a body fat content of at least 22%. The anthropological term for this potential state of fertility is discretion.
On the other hand, not every girl follows a typical pattern, and some girls ovulate before the first menstruation. Although not possible, it is possible for a girl who has had sexual intercourse shortly before menarche to become pregnant and pregnant, which will delay menarche until after the end of pregnancy. This is contrary to the common belief that a woman can not become pregnant until after menarche. Young age at menarche does not correlate with young age at first sexual intercourse.
Onset
When menarche occurs, it confirms that the girl has gradually growing estrogen-induced uterine growth, especially the endometrium, and that the "outlet" of the uterus, through the cervix to the vagina, is exposed.
In very rare cases, menarche can occur at a very young age, before thelarche and other signs of puberty. This is called isolated premature menarche , but other causes of bleeding should be investigated and excluded. Growth is usually normal. Menarche premature isolation is rarely the first manifestation of puberty prematurely.
When menarche has failed to occur for more than 3 years after thelarche, or more than 16 years, this delay is referred to as primary amenorrhea.
Time
Chronic illness
Certain systemic or chronic diseases may delay menarche, such as undiagnosed and untreated celiac disease (often without gastrointestinal symptoms), asthma, type 1 diabetes mellitus, cystic fibrosis and inflammatory diseases, among others. In some cases, since biochemical tests are not always discriminatory, the underlying pathology is not identified and the girl is classified as a postponement of constitutional growth. Short stature, delayed weight and weight growth, and/or delayed menarche may be the only clinical manifestations of celiac disease, in the absence of other symptoms.
Some of the least understood environmental influences at puberty are social and psychological. Almost all research on this effect has been alarming for girls, in part because female puberty requires greater physiological resources and partly because menarche involves a clear threshold event that makes surveying research into female puberty much simpler than men. In most of these studies menarche is specifically examined, assuming it becomes a valid "proxy" for the more common puberty process. Compared to genetic effects, nutrition, and general health, small social influences, time shifts by several months rather than years. The most important part of the child's psychosocial environment is the family.
Some aspects of family structure and function are reported independently associated with early menarche [before and after childhood]
- Not white
- Pre-eclampsia experience in the womb
- Is single
- Have a low birth weight
- Not breastfed
- Exposed to cigarettes
- High conflict family relationships
- Increased incidence of childhood obesity.
- Less exercise in childhood
Other studies have focused on the effects of stress on childhood at the time of puberty, especially of women. Stress is a vague term and studies have examined conditions ranging from family tension or conflict to wartime refugee status with threats to physical survival. More terrible social conditions have been found to be associated with delayed maturation, an effect that can be exacerbated by the inability of the diet. There is more uncertainty and mixed evidence about whether lighter stress levels or early nutritional deficiencies can accelerate puberty in girls as predicted by life history theory and are shown in many other mammals.
This understanding of environmental effects is incomplete and the following observations and warnings are relevant:
- This mechanism of social effects is unknown, although physiological processes, including pheromones, have been suggested based on animal studies.
- Most of these "effects" are statistical associations revealed by epidemiological surveys. Statistical associations are not always causal, and various secondary variables and alternative explanations can be intervened. The small size effect can not be confirmed or denied to every child.
- Despite its small influence, the interpretation of data is politically controversial because of the ease with which it can be used for political advocacy. Allegations of bias on the political agenda sometimes accompany scientific criticism.
- Correlation does not imply causality. While correlations can be measured objectively, causation is statistically inferred. Some suggest that childhood stress is caused by precocious adult puberty later, rather than being the cause.
Age change time average
There are several systematic studies of menarche time before the second half of the 20th century. The oldest estimate of the mean time of menarche is based on observations of small homogeneous populations that do not necessarily represent larger populations, or based on recall by adult women, who are also susceptible to various forms of error. Most sources agree that the average age of menarche in girls in modern society has declined, although the reasons and levels remain the subject of controversy. From the sixth century to the fifteenth century in Europe, most women reached the average menarche about 14 years, between the ages of 12 and 15. The large North American survey only reported a 2-3 month decline from the mid-1970s to mid-year. 1990s. A 2011 study found that every 1 kg/m 2 increase in body mass index of childhood (BMI) can be expected to produce an absolute risk of 6.5% higher than early menarche (before age 12).
Less than 10% of US girls start menstruating before the age of 11, and 90% of all US girls are menstruating at 13.75 years old, with an average age of 12.43 years. This age at menarche was not much different (0.34 years earlier) than was reported for US girls in 1973. Age at menarche for non-Hispanic black girls was significantly earlier than with white girls at 10%, 25 %, and 50% of those who have reached menarche, while Mexican American girls are just a little earlier than white girls at 25%.
Maps Menarche
Culture
Menstruation is a cultural and scientific phenomenon because many societies have certain cultural rituals and norms associated with it. This ritual usually begins in menarche and some are applied to every menstrual cycle. This ritual is important in determining the status change for girls. After menarche and completion of the ritual, they have become a woman as defined by their culture.
For young women in many cultures, first menstruation is a marker that signifies a change of status. Post-menarche, the young woman entered a stage called maidenhood, the stage between menarche and marriage. There is a culture that existed in previous centuries, and today, the ritual rituals that run for a girl experience menarche.
Celebration ceremony
In some cultures, festivals, or celebrations are thrown to show the girl's transition to femininity. This party is similar to the era of quinceaÃÆ' Â ± in Latin America, except that a certain age marks a transition rather than a menarche. In Morocco, the girl was thrown a feast. All of his family members were invited and the girl was bombarded with money and gifts.
When a Japanese girl has her first period, the family sometimes celebrates with eating red rice and nuts . Blood color and red sekihan are not related. All the ancient Japanese rice is red. Since rice is very valuable in ancient Japan (typically, millet eaten), it is eaten only during the celebration. Sekihan is an ancient custom tradition. This celebration is kept secret from large families until rice is served.
In some Indian communities, young women are given a special menarche ceremony called Ruthu Sadangu.
The Mescalero Apaches place great importance on their menarche ceremonies and it is considered the most important ritual in their tribe. Every year there is an eight-day event to celebrate all the girls who have menstruated in the past year. The days are divided between parties and private ceremonies that reflect the status of their new feminine.
Learning ritual
In Australia, Aboriginal people treat a girl to "love magic". She was taught women's ways by other women in her tribe. Her mother built a hut where she confined herself to the rest of her menstranya. The cottage was burned and he was bathed in the river at the end of his menstruation. When she returns to the village, she is paired with a man who will become her husband.
In the United States, public schools have sex education programs that teach women about menstruation and what to expect at the start of menarche (often this happens during grade 4). Historically menstruation has become a social taboo and girls are taught about menarche and menstruation by their mothers or female role models. Then, and so far, menstruation is a personal matter and a girl's menarche is not a community phenomenon.
Purge or purification ritual
The tribe of Ulithi Micronesia calls menarche a girl kufar . She goes to the menstrual house, where the women bathe her and read the spell. She has to go back to her menstrual shack every time she's menstruating. His parents built him a private cottage he would live in until he married.
In Sri Lanka, an astrologer was contacted to learn star alignment when the girl was menarche because it was believed that her future could be predicted. The women of the family then gathered in her home and rubbed it in the ritual bathing ceremony. His family later held a family party where the girl was wearing white clothes and probably received a gift.
In Ethiopia, Jewish Beta women are separated from the male community and sent to menstruary cottages during menarche and every subsequent menstruation when blood related to menstruation in Jewish Beta culture is believed to be impure. Beta Jews build their villages around and near special waters for their women to have a place to clean themselves. The menstrual cottage was built close to this water body.
Ritual of transformation and scarification
In Nigeria, ethnic TIV groups cut four lines into their girl's belly during menarche. The lines should represent fertility.
Power ritual
Navajo held a festival called kinaalda (kinn-all-duh). Girls are expected to show their strength through footraces. The girls made corn pudding for the tribe to taste. Girls who experience menarche wear special clothing and arrange their hair like the Navajo goddess "Changing Women".
Nuu-chah-nulth (also known as Nootka) believes that physical endurance is the most important quality in young women. When menarche, the girl was taken to sea and went there to swim back.
Movies
Probably the most famous movie scene involving menarche is from the 1976 horror film Carrie . Carrie White had her first period when she was bathing after the school gym class, and did not realize what was happening to her, she panicked and begged for help, but the other girls responded by intimidating her. This film is a novel adaptation of the same name by Stephen King. Carrie's first period liberated her vicious power and was the center of dangerous transformation and out of control. This theme is common for horror movies, another notable example is the Canadian horror film 2000 Ginger Snaps , where the first period of the protagonist is the gradual transformation center into a werewolf. Girls who experienced their first period were part of many films, though not essential to their plot, including The Blue Lagoon My Girls A Walk on the Moon me.
See also
- Adrenarke
- Publish pending
- Gonadarche
- Lina Medina, who is menarche at the age of 8 months and is the youngest mother in history
- Menopause, equivalent opposite change at the end of the childbirth years
- Pubarche
- Spermarche
- Thelarche
References
Further reading
Quote: Quinlan, R (2003). Quote: Quinlan, R (2003). "Absence of father, parental care, and female reproductive development" (PDF) . Evolution and Human Behavior . 24 (6): 376-390. doi: 10.1016/S1090-5138 (03) 00039-4. Ã,External links
- For mothers who support their daughters when they reach age
- Gluckman, PD; Hanson, MA (January 2006). "Evolution, development, and time of puberty". Trends in Endocrinology and Metabolism . 17 (1): 7-12. doi: 10.1016/j.tem.2005.11.006. ISSN 1043-2760. PMIDÃ,31 16311040.
- Discusses some social influences
Source of the article : Wikipedia
0 Comments