Regulation of the menstrual cycle - class-X

the functions of the following hormones are:

FSH is responsible for the growth of the Graafian follicle in the ovary. It also promotes the growth of follicles and promotes the secretion of oestrogen in the ovary.
Oestrogen is the female sex hormone. It is responsible for the endometrial thickening and it also helps in the healing of the wall of the uterus.
LH is the Leutenizing hormone and is responsible for the ovulation that takes place on the 14th day of the menstrual cycle.

• The follicular phase of the menstrual cycle is defined as the first day of menstruation until ovulation.
  
• It is initiated by a rise in follicle-stimulating hormone levels on the first day of the cycle. Produced by the hypothalamus.

Low levels of progesterone and estrogen trigger the hypothalamus and anterior pituitary to release gonadotropins. This negative feedback loop stimulates the production of FSH and LH to initiate a new cycle.

Secondary peak level of estrogen in menstruation cycle occurs due to formation of corpus luetum.

• When the production of progesterone and estrogen hormone stops in blood this leads to shed off the lying of uterine endometrium.
  
• Progestrone and estradiol continue the hypertrophy of endo metrial lining in the uterus and fallopian tubes and maintain it throughout pregnancy.
  
• Progesterone is also necessary for the proper implanation of the foetus in the uterine wall. It stimulates tyhe endometrial glands to secrete a nutrient fluid for the foetus, hence the term secretory phase.
  
• Therefore, by supply of estrogen and progesterone the menstruation can be deferred
  

During menstruation cycle, maturation of the follicle is stimulated by follicle stimulating hormone (FSH) from the anterior pituitary, and oestrogen secreted by the follicle lining cells. 

In human females the menstrual cycle starts with the menstrual phase, when menstrual flow occurs and it lasts for 3 - 5 days. The menstrual flow results due to breakdown of endometrial lining of the uterus and its blood vessels, which forms liquid that comes out through vagina. Menstruation only occurs if the released ovum is not fertilised and consequently, there is a fall in blood progesterone level. Post fertilization, the corpus luteum secretes large amounts of progesterone, which is essential for maintenance of the endometrium. 

The menstrual cycle is a complex process regulated by the interplay of several hormones. FSH, LH, and estrogen work together to manage follicle development, ovulation, and uterine lining changes.

Corpus luteum is responsible for higher levels of progesterone whereas LH is responsible for its persistence. As soon as the level of LH decreases, degeneration of corpus luteum takes place. FSH does not play any significant role in the regression of corpus luteum whereas LTH does not have any role in the menstrual cycle.

GnRH stimulates the synthesis and secretion of the two gonadotropins—luteinizing hormone (LH) and follicle-stimulating hormone (FSH)—by the anterior pituitary gland. In order to increase serum gonadotropin concentrations in patients with GnRH deficiency, the releasing hormone must be administered in pulses.
So the correct option is ' FSH and LH from anterior pituitary'.

Progesterone is the ovarian hormone which helps in the development of mammary glands but not the secretion of mammary glands.
So the correct option is 'Stimulation of mammary secretion.’

A primary follicle is surrounded by single or several layers of cuboidal, granulosa cells. It is an immature ovarian follicle. Based on the number of granulosa cell layers, the developing ovarian follicles can be categorised into three classes: primary follicles, secondary follicles, and early tertiary follicles.

The menstrual cycle is regulated by the hypothalamic-pituitary-ovarian axis. FSH, LH, and estrogen are the primary hormones that coordinate the follicular phase, ovulation, and the luteal phase.

If the egg is fertilised by a sperm as it travels down the Fallopian tube, then pregnancy occurs. 

During the preovulatory (follicular) phase, FSH stimulates the growth of ovarian follicles. These follicles, in turn, secrete estrogen, which prepares the uterine lining.

• Corpus luteum secretes large quantity of progesterone and small quantity of estrogen.
  
• In the absence of fertilization, the corpus luteum degenerates resulting in decreased level of progesterone and estrogen.
  
• This causes disintegration of the endometrium leading to menstruation, marking a new cycle.
  

Progesterone levels are higher when the women are pregnant and even the levels are normal during nonpregnancy time. The progesterone levels fall when women reach to menopause stage.

Progesterone and estrogen are necessary to prepare the uterus for menstruation, and their release is triggered by the hypothalamus. Estrogens are a group of sex hormones that promote the development and maintenance of female characteristics in the human body. During the menstrual cycle, estrogen produces an environment suitable for the fertilization, implantation, and nutrition of an early embryo. Progesterone prepares the body for pregnancy by causing the uterine lining to thicken. If a woman is not pregnant, the corpus luteum disappears.

Hormone prepares the body for ovulation before menstrual phase can begin. The pituitary gland releases two hormones, FSH (Follicle Stimulating Hormone) and LH (Luteinizing Hormone). LH stimulates the follicle to manufacture and secrete estrogen. When the amount of estrogen produced in your body reaches a certain level, it causes the pituitary gland to release a surge of LH. The LH surge is what triggers the almost-ripened egg to become fully matured and break through the follicle and the process is known as ovulation.

Estrogens are a group of sex hormones that promote the development and maintenance of female characteristics in the human body. They play an essential role in the growth and development of female secondary sexual characteristics, such as breasts, pubic and armpit hair, and the regulation of the menstrual cycle and reproductive system. Estrogen enhances and maintains the mucous membrane that lines the uterus. It increases the size of the endometrium as well as enhancing blood flow, protein content, and enzyme activity. 

Progesterone belongs to a group of steroid hormones called progestogens. It is mainly secreted by the corpus luteum in the ovary during the second half of the menstrual cycle. It plays important roles in the menstrual cycle and in maintaining the early stages of pregnancy. Progesterone, a hormone secreted by the female reproductive system that functions mainly to regulate the condition of the inner lining (endometrium) of the uterus. When a woman has her menstrual period, her progesterone level is usually low during the first few days.

Luteinizing hormone (LH) and follicle-stimulating hormone (FSH) are called gonadotropins because stimulate the gonads - in males, the testes, and in females, the ovaries. They are not necessary for life but are essential for reproduction. These two hormones are secreted from cells in the anterior pituitary called gonadotrophs. Most gonadotrophs secrete only LH or FSH, but some appear to secrete both hormones.

Menstruation is the shedding of the lining of the uterus (endometrium) accompanied by bleeding. The menstrual cycle is regulated by hormones. Luteinizing hormone and follicle-stimulating hormone, which are produced by the pituitary gland, promote ovulation and stimulate the ovaries to produce estrogen and progesterone. The follicular phase ends when the level of luteinizing hormone increases dramatically (surges). The surge results in the release of the egg (ovulation) and marks the beginning of the next phase.