Reproductive hormones induce estrous cycle. In female, usually, estrous cycle starts after sexual maturity and it is disturbed by anestrous and sometimes pregnancies. Different species have different length of estrous cycle because the duration of the luteal phase is different among them. Estrous groups including monoestrous, diestrous, polyestrous, and seasonal breeders have different number of cycles per year. There are three phases of estrous cycle which are the follicular phase, ovulation phase and the luteal phase. The dominant hormone for the follicular phase is estrogen while for the luteal phase is progesterone. Corpus luteum is established from the cells that remained from ovulated follicle. The estrous cycle consists of 4 different stages. The stages involved are proestrus, estrus, metestrus and diestrus. The first stage is known as the proestrus stage. Time taken for this stage is approximately three days. In this stage, the enlargement of follicle will occur. The time taken for the follicle to enlarge varies among species. During this stage, the estrogen level increases and peak. The progesterone concentration in the circulation also dropped. The vascularity of the female reproductive tract will increase and the endometrial glands start to grow and develop. When the female starts to enter the proestrus stage, some of them might have bloody secretion of the vagina. At the same time, the female is not yet to be what we called as on “heat” which indicate that she is not sexually receptive during proestrus stage. The second stage of the estrous cycle is the estrus stage. This is the phase where the female will start to be on “heat” which means that she is sexually receptive. She will exhibit the sexually receptive behavio... ... middle of paper ... ... F2α. Next, the regression of corpus luteum which is known as luteolysis will occur as well as the decrease in progesterone production. Unlike humans, the lining of uterus is not shed but will reorganize for the next cycle. If the female is pregnant, a phase known as anestrous will occurs. Anestrus is the phase where the sexual cycle rests. It is a seasonal event that is controlled by the exposure of light through the pineal gland that releases melatonin. Anestrus can also be caused by changing of season, stress, pathology and nutritional factor or negative energy balance. It can be concluded that, the estrous cycle is a cycle where the females recur the changes physiologically induced by the reproductive hormones. The cycle begins after the female mature sexually and it is interrupted by the pregnancies. Estrous cycle will continue until the death of the female.
birth and it can even happen subsequently much later in the same year. Men were found to also
This cycle tends to last anywhere from five to seven years and is shorter for hair on the eyebrows, armpits and pubic area. Inside the bulb of each hair is a component called the dermal papilla which controls the hair growth while the matrix of the hair, which contains a large amount of epidermal cells that rapidly divide, is responsible for the length of the hair. Next is the catagen phase which is characterized as a transition period between the anagen and telogen phases. At this time the hair bulbs are pushed out in order to become keratinized and the hair appears short and thick. This phase tends to only last between two and three weeks. During the telogen phase, no new cell division occurs, which means that the length of the hair remains the same. This pause allows the dermal papilla to fill up the matrix with new cells in preparation for the anagen phase to begin again. This phase can last between three and nine months. After this phase, the anagen phase begins again. The telogen phase is periodically followed by shedding, or exogen. This leads to the last phase, the exogen phase. This phase is characterized by the shedding of hair. Each day about one hundred hairs are shed from the average individual’s scalp. The shaft of the hair is shed and the follicle remains. Despite the fat that the exogen phase usually follows the telogen phase, there are exceptions when it does not, resulting in hair follicles needing to go
Cell cycle events portray some differences between different living things. In all the three living things, their cells divide, a process referred to as mitosis. The mitosis stage differs and it encompasses four phases. During development, the cell cycle functions endlessly with newly created daughter cells directly embarking on their path to mitosis. Bacteria cells separate forming two cells after every thirty minutes under favorable conditions. However, the eukaryotic cells take quite longer compared to bacteria cells to develop and divide. Nevertheless, in both animals and plants, cell cycle is usually highly regulated to prevent imbalanced and excessive growth. Both animals and plants are known as eukaryotes meaning that their DNA exists inside their cells’ nuclei. Therefore, their cells as well as mitotic processes are similar in various ways (Eckardt, 2012).
Estrus synchronization is the practice of regulating when one or many mares will be in estrus. Breeders can follow certain protocol in order to cause synchronization in the cycle. According to Samper (2009), there are three methods of inducing estrus. These are induction of luteolysis, prevention of estrus using progestins and progesterone with estradiol which allow natural luteolysis to occur and are almost always combined with a treatment for ovulation induction, and follicular ablation. This paper with examine and explore the hormones, methods, doses and protocols used to synchronize estrus in the mare.
Day after day, late students are punished or end up in detention due to short passing periods. Having short passing periods can make a student’s grade go down or worse when students are late to class. This can be prevented by extending passing periods to 10 minutes. Although the staff at H.P.M.S may disapprove, but in the long run, they will see the effects of having longer passing periods has on students. Because of the short time of passing periods, students at Happy Place Middle School are petitioning to extend their passing period time to 10 minutes. In short, some of the positive effects are that students can get to class on time, and gives students and teachers time to prepare.
should go through and if it doesn’t then the women has an irregular cycle. This process the movement of an egg to a fertilizing position, developing a lining in the uterus, then the shedding of that lining when the egg doesn’t become fertilized.
The history in a family can influence many generations. Certain families have stereotypes about them based on family history. This is a real world situation; the movie The Pregnancy Project, stereotypes about teen pregnancy where shown, and how they affect people. In the Pregnancy Project, the use of Gabi’s background influenced people’s reactions because her family has a history of teen pregnancy.
This source states that women living with epilepsy seem to face different issues than males with epilpesy do. The source states that the two sex hormones inside a woman's body, progesterone and estrogen, play a role in influencing seizures as both of these hormones interact with brain cells. Usually, there are equal amounts of progesterone and estrogen inside a woman's body. However, the problem occurs when the balance of these becomes unequal. It explains that estrogen is an excitatory hormone which basically means that it "makes brain cells give off more of an electrical charge". Prosgesterone, however, is an inhibitory hormone, meaning that it calms the cells - that have been electrically charged by the estrogen - down. The problem arises when the body starts producing more estrogen than progesterone which "can make the nervous system excitable" and can make a woman with epilepsy more exposed to seizures. The source emphasises that a change in hormones don't cause the seizures but they are able to inluence the occurence of seizures. About 10% - 12% of women (with epilepsy) have catamenial epilepsy which means that their seizures are directly affected by their menstrual cycle. The seizures tend to occur when a lot of estrogen is present during the body such as during ovulation. For some others, the seizures can occur when the progesterone levels in the body drop such as during menstruation. It is said that as many as" 40% of menstrual cycles in women with epilepsy do not release an egg" and that women with epilepsy generally produce eggs less often than the normal ...
Schramm, 2011). Another article had study on morphological development and characterization of aromatase and estrogen receptors alpha and beta in fetal ovaries of cattle. In this study the aim was to understand the role of estradiol-17β in fetal ovarian development, presence an localization of cytochrome p450 aromates (P450arom) and estrogen receptors alpha and beta proteins characterized in fetal ovaries of cattle. In the day of 110 of the experiment ovarian structures within different lobes appeared to be different morphological development stages. At the end of this experiment morphological development had analyzed that in granulosa cell growing of oocytes of follicles. Also both ERα and ERβ protein was observed in overigerous cords and granulosa cells and oocytes of follicles. (Burkart, 2009) Similar research had done by Celine Ferre, was “comparison of early morphological and molecular changes induced by 17-alpha-methytestosterone and estradiol benzoate in rat ovary.”(Ferre, 2013) The goal of this experiment was to identify early events and linked to morphological change in the ovary by exposure t...
In a normal, ovulatory cycle the temperature of the body measured on awakening, called the basal state, rises by 0.2C to 0.5C during two or three days following ovulation. This rise is defined as one in which three consecutive daily temperatures are at least 0.2C higher than the six daily temperatures preceding the shift. This rise reflect the secretion of progesterone from the corpus luteum. The
Cross culturally fertility and childbearing are a major concern due to the significance of passing on heritage, family names, and values to the next generation. Additionally, in many cultures the children are responsible for the care of their parents when they become elderly. Infertility is a universal concern in both Western and developing countries. It is estimated that up to 168 million people across the globe are affected with infertility. The bulk of these cases reside within developing countries (Vayena & Rowe, 2002). When couples are having trouble conceiving a child it is a source of distress for both partners (Helman, 2007, p. 176). This distress can be manifested in a variety of ways that adversely affect the family structure.
the ovaries to release an egg once a month but in some cases they release more
The excitement phase is the first phase of the sexual response cycle. This is the phase where things start to “heat up” or both the man and women experience excitement and arousal. To many this stage consists of foreplay, arousing both individuals to want and need the sex. When a man is in this stage he experiences many genital changes, his penis becomes erected, testes enlarge, and skin thickens on the scrotum. Women experience more changes than the man, their breasts enlarge, the clitoris swells, the vaginal lips flatten and swell, and also the vaginal lubrication will form. Men and women in this phase also will experience some of the same effects. Both will experience elevated heart rates and blood pressures, and in some individuals the nipples will erect. (Nevid & Ruthus, 2005).
The female reproductive systems is made of 9 parts. The sex cell for the female reproductive system is called the egg or ovum. The egg spends it’s dormant life in the ovaries until it is released. The egg has 23 chromosomes within it. The ovaries have two goals: to create and house eggs and the release the female sex hormones, estrogen and progesterone. The fallopian tubes are what the egg travels through to reach the uterus. Fallopian tubes contain tiny hair-like structures called cilia; the cilia allows for mobility of the egg. The fallopian tube is roughly the size of 2 hairs, and is the site of where ectopic pregnancies happen. The process of the egg getting released from the ovaries through the fallopian tubes is called ovulation. Ovulation happens on the 14th day of the menstruation cycle The uterus is where the egg goes to after it travels through the fallopian tubes. The developing baby is held and nourished in the uterus. When the uterus is empty, it’s roughly the size of a fist but expands one an embryo starts to develop. The endometrium is the lining of the uterine wall. It’s used to protect the fetus. When the egg isn’t fertilized, menstruation ha...
Menstruation, also known as a menstrual period, is the monthly shedding of the lining of the uterus. The uterus is the organ in the lower abdomen where a baby grows during pregnancy. Menstruation involves the passing of blood, tissue, fluid, and mucus. The flow of blood usually occurs during 3–7 consecutive days each month.