Hormones in the Menstrual Cycle

Woman's menstrual cycle is very resolute by a convoluted interaction of diverse hormones. The major hormones engaged in the menstrual cycle is a gonadotropin releasing hormone (GnRH), follicle stimulating hormone (FSH), luteinizing hormone (LH), estrogen, and progesterone. GnRH is secreted by the hypothalamus , FSH and LH secreted by the pituitary gland anterior, and estrogen and progestin secreted in the ovaries. GnRH stimulates the issue of LH and FSH from the anterior pituitary, which in turn stimulates the release of estrogen and progestin from the ovary.
Gonadotropin issuing Hormone (GnRH)

Gonadotropin issuing hormone (GnRH) released from the hypothalamus that pulsed throughout the menstrual cycle. In alignment to take the usual menstrual cycle, GnRH should be released in pulses. On mean, the frequency of GnRH secretion is one time per 90 minutes in the early follicular stage, increasing to one time per 60-70 minutes, and decreases with increasing amplitude during the luteal stage. GnRH induces the issue of FSH and LH, but LH is much more perceptive to alterations in grades of GnRH.
Follicle Stimulating Hormone (FSH)

Follicle stimulating hormone (FSH) secreted by the anterior pituitary gland and is absolutely vital for the development of antral follicles to augment. FSH secretion reaches its top and most critical during the first week of the follicular stage of the menstrual cycle. FSH induces the secretion of estrogen and progesterone from the ovaries to activate the enzyme aromatase and p450 and exert contradictory feedback on GnRH secretion. FSH induces farther proliferation of granulosa cells and LH receptor sign in granulosa cells.
Luteinizing Hormone (LH)

Luteinizing hormone (LH) secreted by the anterior pituitary gland and is essential for the development of preovulatory follicles and luteinization and ovulation superior follicle. throughout the follicular stage of the menstrual cycle, LH induces androgen synthesis by cells of theca folikuli ; ​​stimulate expansion, differentiation, and secretion folikuli theca units, and increases LH receptors in granulosa units. Preovulatory LH rush push-division oocyte meiotic first and start luteinizing theca cells and granulosa. corpus luteum is then produce a number of progesterone and estrogen.

Estrogen is made in the ovaries and is absolutely vital for the development and maturation of antral Graafian follicles. Estrogens play a superior function in the late follicular phase until just before ovulation. Estradiol, the most powerful estrogen and abundant, mostly derived from androgens made by the theca cells. Androgen migrate from the theca units to the granulosa units, where they are altered to estradiol by the enzyme aromatase. A number of estradiol can furthermore be produced through de novo synthesis by the theca units. Perform activities encompassing induction estradiol FSH receptors on granulosa cells, proliferation and secretion of follicular theca units, induction of LH receptors in granulosa units, and proliferation of stromal units and endometrial epithelium. At the reduced grade circulation, use estrogen negative repsonse on LH and FSH secretion, but at a very high level of estrogen exert positive repsonse on LH and FSH secretion. Estrogen induces further expansion of granulosa units and synthesize estrogen converting estrogen receptor, therefore conceiving a affirmative repsonse for herself. In the endometrial cycle, estrogen induces expansion of endometrial glands.

Progestin secreted in the ovaries, especially by terluteinisasi follicles. Progestin grades increase just before ovulation and peaked five to seven days post-ovulation. The first step in the synthesis of progestins requires p450 enzymes and progestin are two types of circulating progesterone and progesterone-hydroxy-17. Progestin stimulates the release of proteolytic enzymes from the theca units, which in turn organises ovulation. farther progestin induces migration of blood vessel walls into the follicle and stimulate the secretion of prostaglandins in follicular tissue. During the luteal phase, progestin induces enlargement and bigger secretion of the endometrium.


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