What is the menstrual cycle PDF

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Activating Effects of Hormones: The Menstrual Cycle

Psychobiology – Prof. Melissa Ferguson Class Exercise

1. What is the menstrual cycle? The menstrual cycle is the periodic variation in hormones and fertility over the course of about 28 days. It is controlled by the hypothalamus, pituitary and ovaries (HPG axis). 2. At the end of a menstrual period what hormone does the anterior pituitary release? The anterior pituitary releases Follicle-Stimulating Hormone (FSH).

3. What is the role of FSH in the menstrual cycle? FSH promotes growth of the follicle in the ovary, which nurtures the egg and produces estrogen.

4. Increased estradiol released from the follicle causes the anterior pituitary to release what hormones? Towards the middle of the menstrual cycle, the follicle builds up receptors to FSH. As a result, the follicle produces increasing amounts of estradiol, which causes an increase in FSH and the anterior pituitary to release Luteinizing Hormone (LH).

5. What happens when FSH and LH release peaks near the middle of our cycle? When FSH and LH release peaks it causes the follicle to release an egg, or ovulation. 6. Why do the remnants of the follicle release the hormone progesterone? Remnants of the follicle release progesterone to prepare the uterus for implantation of the fertilized egg and to inhibit further release of LH. 7. What happens if the ovum is not fertilized? If the ovum is not fertilized, the corpus luteum withers and falling levels of hormones causes shedding of the uterine lining as the menstrual flow. 8. What happens if the ovum is fertilized? If the ovum is fertilized, no menstruation occurs, as the corpus luteum continues to function secreting progesterone during first 3 months of pregnancy. 9. How do birth control pills work? Birth control pills prevent pregnancy by interfering with the usual feedback cycle between the ovaries and pituitary in a combination of ways like preventing the surge of FSH and LH, or thickening the mucus in the cervix to prevent sperm from reaching the egg, and preventing the egg, if released, from implantation....