what is estrous cycle?
602360
The estrous cycle (also oestrous cycle; originally derived from Latin œstrous) refers to the recurring physiologic changes that are induced by reproductive hormones in most mammalian placental females; humans and great apes are the only mammals who undergo a menstrual cycle instead. Estrus cycles start after puberty in sexually mature females and are interrupted by anestrous phases. Typically estrus cycles continue until death. Some animals may display bloody vaginal discharge, often mistaken for menstruation.
86834
Menopause, or premenopause, whichever stage you are in is very unpredictable.  There is a book I love called "What Your Doctor May not Tell You About Premenopause" by dr. John Lee.  That man changed my life and answered questions my regular ob/gyn glared at me for asking.
215548
Only if it's an extremely radical change from your normal dietary habits.  But menstrual cycles will weaken or even disappear if you're not getting the minimal amount of kilocalories (usually c. 1200 per day) that your body needs, or if you are depriving your body of basic nutrients found in animal products (hemoglobin, calcium, etc.)  Although usually these cycle changes are temporary and end after you renourish your body with calories/nutrients, be careful, as this can cause permanent damage to your reproductive system.
312280
women have a monthly cycle, but men actually have a daily cycle.  It is run on testosterone and runs highest around 3PM or so and lowest around 8PM. Notice how most men seem to be more mellow at night and agitated in the afternoon?  That is why.
810756
The menses is a sloughing off of the uterine walls that are ready for a fertilised egg to imbed in the uterus. Once this occurs the menstrual cycle ceases. If the sloughing off were to happen it would be a miscarriage.
181307
Estradiol is  an artifical hormone, birth control pill,--to keep you from becoming pregnant.  If the level is low, it won't work to prevent pregnancy.  Always wear protection anyway, to protect from STD and AIDS.
911731
in females the ovaries start producing ovum,female gamete at definite age<10-12>.after this age,ovaries start exhibiting a cycle of events at definite intervals<28-30days>.the ovarian follicles grow into mature ones<ovums>.as it matures a no. of things happen,the uterus wall thickens to get ready for fertilisation,if it does not then these thickened wall breaks,along with blood vessels and comes out as bleeding,which we call it as menstrual flow<lasts for 4-7 days>.this cycle of events taking place every 28 -30 days is called as menstrual cycle.
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Women are more emotional than men are...for the most part.  Plus alot of it is hormonal. Our cycles change several times in the matter of a month. And what do you mean I am moody?!!!  lmto! :op~~
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In humans, the period when ovulation occurs is called the ovulatory phase, and it occupies the fourteenth day of an idealized twenty-eight day menstrual cycle. Because of the variable nature of the menstrual cycle in vivo, however, normal ovulation can occur as early as day 8 or as late as day 20 and beyond. A woman with a particularly short cycle will ovulate earlier while a woman with a long cycle will ovulate later. In humans, concealed ovulation means that the female shows few visible signs of being fertile, compared to most species.(disputed — see talk page) There are evolutionary analyses of how this could evolve in terms of evolutionary game theory.\n\nBefore ovulation, the ovarian follicle will undergo a series of transformations that are necessary for the ovum to survive afterwards. This process is called cumulus expansion. After this is done, a hole called the stigma will form in the follicle, and the ovum will leave the follicle through this hole. It will then enter the fallopian tubes and travel toward the uterus, implanting there 6-12 days later if fertilized, or degrading in the fallopian tubes within 24 hours if not fertilized.\n\nThe ovulatory phase is preceded by the follicular phase, where an immature follicle-encased ovum completes growing, and followed by the luteal phase, where the uterus is prepared to receive the fertilized ovum. The complete process of follicle growth leading up to ovulation is known as folliculogenesis.\n\nScientific investigations like [1] have indicated that the olfactory acuity or the sense of smell is greatest during ovulation in women.\n\n[edit]\nA closer look at the process\nStrictly defined, the ovulatory phase spans the period of hormonal elevation in the menstrual cycle. The process requires a maximum of thirty-six hours to complete, and it is arbitrarily separated into three phases: periovulatory, ovulatory, and postovulatory.\n\n[edit]\nPrerequisite events\n \nHistology of the preovulatory follicleMain page: folliculogenesis\n\nThrough a process that takes approximately 375 days, or thirteen menstrual cycles, a large group of undeveloped primordial follicles dormant in the ovary is grown and progressively weaned into one preovulatory follicle. Histologically, the preovulatory follicle (also called a mature Graffian follicle or mature tertiary follicle) contains an oocyte arrested in prophase of meiosis I surrounded by a layer corona radiata granulosa cells, a layer of mural granulosa cells, a protective basal lamina, and a network of blood-carrying capillary vessels sandwiched between a layer of theca interna and theca externa cells. A large sac of fluid called the antrum predominates in the follicle. A "bridge" of cumulus oophorous granulosa cells (or simply cumulus cells) connects the corona-ovum complex to the mural granulosa cells.\n\nSimply stated, the granulosa cells engage in bidirectional messenging with the theca cells and the oocyte to facilitate follicular function. Research is elucidating the specific factors used in follicular messenging at a rapid pace, but such discussion is beyond the scope of this article.\n\nBy the action of luteinizing hormone (LH), the preovulatory follicle's theca cells secrete androstenedione that is aromatized by mural granulosa cells into estradiol, a type of estrogen. High levels of estrogen have a stimulatory effect on hypothalamus gonadotropin-releasing hormone (GnRH) that in turn stimulates the expression of pituitary LH and follicle stimulating hormone (FSH).\n\nThe building concentrations of LH and FSH marks the beginning of the periovulatory phase.\n\n[edit]\nPeriovulatory phase\nFor ovulation to be successful, the ovum must be supported by both the corona radiata and cumulus oophorous granulosa cells. The latter undergo a period of proliferation and mucification known as cumulus expansion. Mucification refers to the secretion of a hyaluronic acid-rich cocktail that disperses and suspends the cumulus cell networ
442805
there is a really obscure word for it: vernalagnia. its definition is just related to heightened sexual desire during the springtime.
1115461
It's a pain, It happens when the females egg isn't fertilized, it's removed from the body and than a new one is put in it's place.\n\nIf fertilization and pregnancy do not ensue, the uterus sheds the lining, culminating with menstruation, which marks the low point for estrogen activity. This manifests itself to the outer world in the form of the menses (also menstruum): essentially part of the endometrium and blood products that pass out of the body through the vagina. Although this is commonly referred to as blood, it differs in composition from venous blood.
752635
Higher primates are the only group of animals that have a menstrual discharge - other animals reorganise their ovarian tissue through the cycle but don't get rid of it.  So whales don't technically have a "menstrual cycle" measured from one mense to the next, but an ovarian cycle which measures form one heat to the next, as is the case in most mammals.  The two are NOT the same thing - our menstrual cycle does not correspond with our fertile period whilst "heat" does.  A dog's bloody discharge during heat is due to leaky capillaries in the ovarian wall during pro oestrus, contains blood and serous fluid, and is a trait peculiar to the dog.
1042930
The water cycle — technically known as the hydrologic cycle — is the continuous circulation of water within the Earth's hydrosphere, and is driven by solar radiation. This includes the atmosphere, land, surface water and groundwater. As water moves through the cycle, it changes state between liquid, solid, and gas phases. Water moves from compartment to compartment, such as from river to ocean, by the physical processes of evaporation, precipitation, infiltration, runoff, and subsurface flow. Movement of water within the water cycle is the subject of the field of hydrology.
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Only the members of family Hominidae (man, the chimpanzees, gorillas and orangutans) have a menstrual cycle. The discharge from dogs and other mammals (all other mammals undergo estrus) doesn't correspond to the same phenomenon. \nThe changes during the menstrual cycle occur mainly at the endometrium (the inner lining of the uterus), whereas the major changes during estrus occur at the vaginal epithelium. In menstruating animals, the discharge of blood is formed by the endometrial walls and occurs when there is no fertilization. In other mammals, there may be some bloody vaginal discharge, but the endometrium is reabsorbed if no fertilization occurs (no menses).
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Because it has recently been discovered males go through the same type of hormonal cycle that women do.  The difference is that the male cycle is based on androgens, and runs on a 45 day cycle (on the average) rather than a 28 day one.  For males who are more sensitive to hormonal shifts or who have greater hormonal shifts during their cycle, it will seem like they experience exaggerated moodiness, though if you watch closely enough, most males will experience some degree of it.
350424
Birth control pills, or your menstrual cycle.
664039
The average (normal) menstrual cycle is 28 days.\n\n\nPs. I am absolutely sure of this. I am secondary school science teacher and I double checked at home in my Medicine dictionary.