menarche
Quick Summary
Menarche refers to the onset of menstruation, typically occurring between the ages of 10 and 16. This event is a significant sign of puberty and the development of the reproductive system in females. It is preceded by other indicators of estrogenic activity, such as breast enlargement and the growth of pubic hair.123
The menstrual cycle itself involves the periodic discharge from the vagina of blood, secretions, and the uterine lining. This process is regulated by hormones produced by the ovaries, primarily estrogens and progesterone, which are influenced by the pituitary gland and hypothalamus. While the first few menstrual cycles can sometimes be irregular, this usually resolves on its own. The timing of menarche can vary significantly among individuals, influenced by genetics and environmental factors like nutrition.3456
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populationBiological factors affecting human fertilityā¦measured by the age of menarche (onset of menstruation), British data suggest a decline from 16ā18 years in the mid-19th century to less than 13 years in the late 20th century. This decline is thought to be related to improving standards of nutrition and health. Since the average age ofā¦
Read Moreā¦measured by the age of menarche (onset of menstruation), British data suggest a decline from 16ā18 years in the mid-19th century to less than 13 years in the late 20th century. This decline is thought to be related to improving standards of nutrition and health. Since the average age ofā¦
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human developmentDevelopment of the reproductive organs and secondary sex characteristicsMenarche, the first menstrual period, is a late event in the sequence. Though it marks a definitive and probably mature stage of uterine development, it does not usually signify the attainment of full reproductive function. The early cycles may be more irregular than later onesā¦
Read MoreMenarche, the first menstrual period, is a late event in the sequence. Though it marks a definitive and probably mature stage of uterine development, it does not usually signify the attainment of full reproductive function. The early cycles may be more irregular than later onesā¦
Read More- human developmentLarger size and earlier maturation
ā¦a potent cause of early menarche, but it seems that their effect, if any, is considerably less than that of nutrition. Some authors have supposed that the increased psychosexual stimulation consequent on modern urban living has contributed, but there is no positive evidence for this.
Read Moreā¦a potent cause of early menarche, but it seems that their effect, if any, is considerably less than that of nutrition. Some authors have supposed that the increased psychosexual stimulation consequent on modern urban living has contributed, but there is no positive evidence for this.
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menstruationThe menarcheThe first menstruation, or menarche, usually occurs between ages 10 and 16, but in a few otherwise normal children menstruation may begin sooner or may be delayed. If the menstrual periods have not started by the age of 16 gynecological investigation is indicated. Theā¦
Read MoreThe first menstruation, or menarche, usually occurs between ages 10 and 16, but in a few otherwise normal children menstruation may begin sooner or may be delayed. If the menstrual periods have not started by the age of 16 gynecological investigation is indicated. Theā¦
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