menstruation

enUK

menstruation,

periodic flow of blood and cells from the lining of the uterusuterus,
in most female mammals, hollow muscular organ in which the fetus develops and from which it is delivered at the end of pregnancy. The human uterus is pear-shaped and about 3 in. (7.
..... Click the link for more information. in humans and most other primates, occurring about every 28 days in women. Menstruation commences at puberty (usually between age 10 and 17). The onset of menstruation, called menarche, signals the body's coming readiness for childbearing. It continues, unless interrupted by pregnancypregnancy,
period of time between fertilization of the ovum (conception) and birth, during which mammals carry their developing young in the uterus (see embryo). The average duration of pregnancy in humans is about 280 days, equal to 9 calendar months.
..... Click the link for more information. until menopausemenopause
or climacteric
, transitional phase in a woman's life when the ovaries stop releasing eggs, ovarian production of estrogen and other hormones tapers off, and menstruation ceases.
..... Click the link for more information. (around age 50).

There have been many myths and taboos associated with menstruation. Some cultures isolated women or thought the menstrual flow "unclean" or a "curse." More recent taboos against exercise or sexual intercourse during menstruation are slowly lifting. Some scientists have asked why menstruation occurs at all—why the uterine lining does not remain in place, regenerating itself as other parts of the body (such as the skin and digestive tract) do. One theory is that menstruation is a defense against microbes that enter the uterus with incoming sperm.

The Menstrual Cycle

In the first phase of each cycle, the lining, or endometrium, of the uterus undergoes rapid proliferation of cells and venous channels in preparation for pregnancy. Midway through the cycle an ovumovum
, in biology, specialized plant or animal sex cell, also called the egg, or egg cell. It is the female sex cell, or female gamete; the male gamete is the sperm. The study of the ovum is included in the science of embryology.
..... Click the link for more information. (egg) is released from an ovaryovary,
ductless gland of the female in which the ova (female reproductive cells) are produced. In vertebrate animals the ovary also secretes the sex hormones estrogen and progesterone, which control the development of the sexual organs and the secondary sexual characteristics.
..... Click the link for more information. . If, while passing through the fallopian tubefallopian tube
, either of a pair of tubes extending from the uterus to the paired ovaries in the human female, also called oviducts, technically known as the uterine tube.
..... Click the link for more information. the ovum is fertilized by a sperm, implantation in the uterus occurs and the thickened lining helps support the pregnancy. When the ovum is not fertilized, this tissue and blood are shed. The proliferation of the uterine wall then begins once more in expectation of the next release of an ovum, and if conception does not take place, it sloughs off again. The process continues monthly until pregnancy occurs or until ovulation ceases at menopause.

The natural rhythm of the menstrual cycle may be broken or temporarily halted by hormonal imbalance, malnutrition, illness, or emotional disturbance (see amenorrheaamenorrhea
, cessation of menstruation. Primary amenorrhea is a delay in or a failure to start menstruation; secondary amenorrhea is an unexpected stop to the menstrual cycle.
..... Click the link for more information. ). Menstruation is controlled by the hypothalamushypothalamus
, an important supervisory center in the brain, rich in ganglia, nerve fibers, and synaptic connections. It is composed of several sections called nuclei, each of which controls a specific function.
..... Click the link for more information. and the pituitary glandpituitary gland,
small oval endocrine gland that lies at the base of the brain. It is sometimes called the master gland of the body because all the other endocrine glands depend on its secretions for stimulation (see endocrine system).
..... Click the link for more information. and hormones, such as estrogenestrogen
, any one of a group of hormones synthesized by the reproductive organs and adrenal glands in females and, in lesser quantities, in males. The estrogens cause the thickening of the lining of the uterus and vagina in the early phase of the ovulatory, or menstrual, cycle
..... Click the link for more information. , which prepares the lining of the uterus, and progesteroneprogesterone
, female sex hormone that induces secretory changes in the lining of the uterus essential for successful implantation of a fertilized egg. A steroid, progesterone is secreted chiefly by the corpus luteum, a group of cells formed in the ovary after the follicle
..... Click the link for more information. , which helps maintain a pregnancy.

Dysmenorrhea and Premenstrual Syndrome

Many women experience painful menstruation, or dysmenorrhea. The uterine contractions that result in the cramps experienced by these women appear to be caused by hormones called prostaglandins that are produced in the second half of the cycle. Oral contraceptives and other drugs that reduce the production of prostaglandins are sometimes used in treatment. Other women experience symptoms such as behavioral changes, breast tenderness, and fatigue during the week immediately preceding menstruation, a condition referred to as premenstrual syndromepremenstrual syndrome
(PMS), any of various symptoms experienced by women of childbearing age in the days immediately preceding menstruation. It is most common in women in their twenties and thirties.
..... Click the link for more information. , or PMS.

Bibliography

See publications of the National Institute of Child Health and Human Development; Boston Women's Health Book Collective, Our Bodies, Ourselves for the New Century (1998).

Menstruation

Periodic sloughing of the uterine lining in women of reproductive age. Menstrual bleeding indicates the first day of the menstrual cycle, which lasts an average of 27–30 days, although ranges of 21–60 days have been recorded. Menarche, the onset of menstruation, occurs between the ages of 9 and 16. The majority of females begin menstruating at ages 12–14. During the first few years, the duration and intensity of menstrual flow and the total cycle length may be quite variable, but regularity is gradually established. Cessation of menses, or menopause, occurs at an average age of 51, with a range of 42–60 years.

The menstrual cycle consists of cyclic changes in both the ovary and the uterus. These changes are controlled by the interaction of several hormones including follicle-stimulating hormone (FSH) and luteinizing hormone (LH), which are secreted by the anterior pituitary, and the steroid hormones estrogen and progesterone, which are secreted by follicles in the ovary. At the beginning of the cycle, the follicle is stimulated by FSH. In response, it grows and secretes estrogen. The amount of estrogen secretion increases rapidly near the middle of the cycle. Estrogen, in turn, stimulates growth of the uterine lining (mucosa), which becomes thicker and fills with blood vessels. In midcycle, the rapid increase in estrogen causes a massive surge of LH release and a smaller release of FSH from the pituitary. This surge causes ovulation, which is the release of the ovum from the follicle. After ovulation, the follicle undergoes rapid changes and is then called a corpus luteum, which secretes progesterone in response to LH stimulation. Progesterone and estrogen together cause a further thickening of the uterine mucosa, preparing the uterus for pregnancy. If pregnancy does not occur, the corpus luteum degenerates, the uterine mucosa sloughs off, and the cycle begins again.

There is no menstrual bleeding during pregnancy, as the uterine mucosa is needed for the maintenance of pregnancy. This amenorrhea, or lack of normal ovarian function, sometimes continues during nursing.

menstruation

[‚men·strə′wā·shən] (physiology) The periodic discharge of sanguineous fluid and sloughing of the uterine lining in women from puberty to the menopause. Also known as menses.

menstruation

the approximately monthly discharge of blood and cellular debris from the uterus by nonpregnant women from puberty to the menopause

Menstruation

(dreams)It is a common dream for women and its interpretation is mostly positive. Dreaming about having your menses can be symbolic of releasing tension and worry. Women are often concerned about their reproductive system. (i. e., pregnancy, sexual relationships or their body’s “time clock” ). Parallel to the menstrual cycle there is a monthly emotional cycle that most women are aware of and experience. During the time of menstruation there is a release of anxiety and an attainment of emotional balance. As a dream symbol it suggests that some difficult times may be over for you and that you can relax. On occasion this dream suggests a loss of energy and disappointment.

menstruation

enUK

menstruation

[men″stroo-a´shun] the periodic discharge from the vagina of blood and tissues from a nonpregnant uterus; the culmination of the menstrual cycle. Menstruation occurs every 28 days or so between puberty and menopause, except during pregnancy, and the flow lasts about 5 days, the times varying from woman to woman.Menstrual Difficulties. Some menstrual discomfort is common, but acute discomfort is usually indicative of some disorder. Among the disorders sometimes causing dysmenorrhea are leiomyoma uteri, endometrial cysts, and displacement of the uterus. Menstrual pain may in some cases be related to tension or anxiety. Excessive bleeding or prolonged periods (hypermenorrhea) are sometimes an indication of tumors, polyps, cancer, or inflammation.
Menstruation usually starts between the ages of 11 and 14 and continues into the forties or fifties. At first the periods may be irregular, but once they are established they usually occur in a fairly definite rhythm, at intervals of 21 to 35 days. In these regular cycles, there may be monthly variations of a few days, which are considered normal. Cycle length may be influenced by changes in climate or living conditions, or by emotional factors. Slight irregularities, especially if they occur over a period of time, may be warnings of disturbance of either the thyroid or pituitary glands, or of tumors of the uterus or ovaries.
Occasionally menstruation does not occur at puberty; this is known as primary amenorrhea. It may be caused by underdevelopment or malformation of the reproductive organs, or by glandular disturbances, which generally can be corrected by the administration of hormones.
General ill health, a change in climate or living conditions, emotional shock, or, frequently, either the hope or fear of becoming pregnant can sometimes stop menstruation after it has begun (secondary amenorrhea). If this cessation is of short duration, it is not a cause for alarm. If it continues over a long period of time, and there is also the problem of infertility, hormone treatments may be necessary.anovular menstruation (anovulatory menstruation) periodic uterine bleeding without preceding ovulation.vicarious menstruation bleeding from extragenital mucous membrane at the time one would normally expect the menstrual period.

men·stru·a·tion

(men-strū-ā'shŭn), Avoid the misspellings and mispronunciations menestration, menstration, and other variants.Cyclic endometrial shedding and discharge of a bloody fluid from the uterus during the menstrual cycle of humans and primates. [see menstruate]

menstruation

(mĕn′stro͞o-ā′shən)n. The monthly flow of blood and cellular debris from the uterus that begins at puberty in women and the females of certain other primates. In women, menstruation ceases at menopause. Also called catamenia, menses.

The normal discharge of blood and tissue from the endometrium via cervix/vagina (or the process itself) from the uterus at the end of a menstrual cycle, which usually occurs at ± 4 week intervals, ± 2 weeks after ovulation

menstruation

Menorrhea The discharge of blood and tissue or the process itself from the uterus at the end of a menstrual cycle, occurring at ±4 wk intervals, ±2 wks after ovulation. See Vicarious menstruation. Cf Amenorrhea.

men·stru·a·tion

(men'strū-ā'shŭn) Cyclic endometrial shedding and discharge of a bloody fluid from the uterus during the menstrual cycle.
See: menstruate

menstruation

The periodic shedding of the lining (ENDOMETRIUM) of the womb (uterus) at intervals of about 28 days causing bleeding through the vagina of 3 to 7 days duration in the non-pregnant female. The purpose of menstruation is to renew the endometrium so that it is in a suitable state to ensure implantation of a fertilized egg (ovum).

menstruation

see MENSTRUAL CYCLE.

Patient discussion about menstruation

Q. preventing pre menstrual MIGRAINES. Has anyone come up with any good preventive medicine for migraines? Mine come systematically right before and during the menstrual cycle. My (male) neurolight in Paris didn't seem to see a linkk with migraines and my cycle - or offer any preventive advice. I take Relpax to relieve. Does anyone have a more natural or preventive solution? A. I have the same problem and take Topomax to prevent the migrains. Also make sure you get enough rest right before you start. There seems to be a correlation. It took about 2 months to fully work but at least the first migrain after I started taking Topomax wasn't as severe.

Q. can you get poly-cystic ovarian syndrome when you still have your menstrual cycle? A. polycystic ovarian syndrome is when the egg does not come out- so i guess there is no menstrual that month. but as far as i know it's not every month that an egg decides to stay at home after 18... i guess you can check up more exact at this site:
http://www.pcosupport.org/

Q. is it normal to get a nausous feeling around the time i would start my menstrual cycle? A. Yes, it is absolutely normal to feel nausea before and during menstrual cycle. The shift in hormonal levels can cause also headaches, mood changes, feeling of bloating and other common symptoms.

More discussions about menstruation

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The Menstrual Cycle

Dysmenorrhea and Premenstrual Syndrome

Bibliography

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Patient discussion about menstruation

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Synonyms for menstruation

noun period

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Synonyms for menstruation

noun the monthly discharge of blood from the uterus of nonpregnant women from puberty to menopause

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