Biology, asked by Anonymous, 7 months ago

explain menstrual cycle​

Answers

Answered by Anonymous
3

Answer:

what is menstrual cycle

Menstruation describes the female period. The menstruation cycle begins when a woman gets her periods. The menstrual blood which leaves her body are products shed from the uterus (the uterine lining also called the endometrium). During the remainder of the menstrual cycle the uterine lining regrows. It does so in preparation for pregnancy, which occurs if the egg (oocyte) a woman releases about half way through her menstrual cycle is fertilised. When fertilisation occurs, the lining stays in place to nourish the fertilised egg. When fertilisation does not occur the menstrual cycle continues and the uterine lining is shed marking the start of the woman’s next menstrual period. Women begin menstruation at an average age of 13 (called menarche) and on average continue menstruating till age 51 (called menopause).Menstruation involves highly complex hormonal interactions. The key hormones involved in menstruation are oestrogen and progesterone (produced by the ovaries) and luteinising hormone and follicle stimulating produced by the pituitary gland, under the influence of hormones secreted by the hypothalamus. The interactions between these organs are referred to as the hypothalamic-pituitary-ovarian axis (HPO axis).

Phases of the menstrual cycle

The menstruation cycle refers to the cycles in which a woman’s uterus grows and sheds a lining (the endometrium) which could support the development of a fertilised egg. It typically occurs in 28 day cycles, so a woman generally gets her period every 28 days. However, cycle length may be as short as 21 days or as long as 40 days in some women. The inner lining of the uterus (the endometrium) goes through three phases during the typically 28 day menstrual cycle: the menstrual phase (days 1-5), the proliferative phase (days 6-14) and the secretory phase (days 15-28).

The ovarian cycle, refers to the cycle in which a woman’s ovaries prepare an egg to be released during ovulation. It is divided into two phases: the follicular phase (days 1-14) and the luteal phase (days 15-28), during which different levels of hormones are released. These two cycle occur in a synchronised manner; day 1 of the ovarian cycle is always also day 1 of the menstrual cycle.

Day 1 of the menstrual cycle coincides with the start of a woman’s period (menstrual bleeding) in which the uterus sheds the lining (endometrium) built up in the previous menstrual cycle. The lining of the uterus is regrown during each menstrual cycle. Menstrual bleeding typically continues for 3-5 days in what is known as the menstrual phase of the cycle. Between 50-150ml of blood is released during this period.

After the woman’s period, the proliferative phase of the menstrual cycle begins. The uterine lining is regenerated in preparation for receiving a fertilised egg (should fertilisation occur). The regrowth of the lining each month is needed to create an environment suitable for development of a fertilised egg. If the egg released during ovulation is fertilised and the woman becomes pregnant, the uterine lining stays in place and nourishes the fertilised egg

As the uterus is preparing its lining in the proliferative phase, the woman’s ovaries are preparing an egg for release. Her oestrogen levels rise stimulating the growth of several ovarian follicles. Each of the follicles contains one egg (oocyte) which matures as the follicle grows. Usually only one follicle (known as the dominant follicle) fully matures and releases the egg it contains. The release of the egg is referred to as ovulation. Rarely a woman will develop and release two or more eggs, and this is when multiple pregnancy occurs (e.g. triplets, depending on the number of eggs released).

In a typical 28 day cycle, ovulation or the release of a mature egg occurs on Day 14, marking the end of the follicular phase. Ovulation will occur earlier in shorter cycles and later in longer cycles. Ovulation occurs when levels of luteinising hormone (a hormone secreted by the pituitary gland in the brain) in the woman’s body rise rapidly. The surge in luteinising hormone signals the ovaries to release the mature egg/s and marks the beginning of the luteal phase of the ovarian cycle. Once released from the ovaries an egg may be fertilised by male sperm, in which case it will be nourished by the uterine lining and establish a pregnancy. Pregnancy changes the woman’s hormonal balance and interrupts the menstrual and ovarian cycles. If the egg is not fertilised it will exit the woman’s body and the ovarian and menstrual cycles continue.

Menstruation Calculator

Menstruation occurs in cycles. The ovaries prepare an egg (oocyte) for release and the womb (uterus) prepares a lining to nourish the egg if it is fertilised. When the egg is not fertilised, the lining of the womb is shed and a woman gets her period (menstrual bleeding).

Answered by Anonymous
1

Տ -

After monthly ovulation, if the ovum is not fertilized then the ovum will just flow out through vagina with all the extra blood. This is menstrual cycle. Every month one egg leaves the ovary. This stats happening from puberty onwards. The start of menstruation is known as menarche, the end of menstruation is known as menopause. The menopause can occur anywhere between the age of 45 - 60 years.

HoPe iT HeLpS YoU ♥️♥️♥️

Similar questions