Answer:

MELC 2: Describe the feedback mechanism involved in the regulating processes in the female reproductive system (e.g. menstrual cycle) (S10LT-lllc 35)

10. A. Days 1-5

11. B. Thinning of the Graafian follicle membrane

12. D. Ovulation

13. D. There is a constant level of estrogen in the ovaries.

14. B. Neutral Feedback Mechanism

15. C. It is the process through which the level of one substance (hormone) influences the level of another substance.

Explanation:

10. The menstrual phase occurs at the very beginning of the uterine cycle. It only occurs if no ovum is fertilised. The process begins with the breakdown of the corpus luteum which therefore ceases to produce progesterone. The loss of progesterone causes vasoconstriction of the spiral arteries supplying the functional layer of the endometrium. As a result, it becomes necrotic and is then lost through the vagina causing the 3-5 days of bleeding.

11. Luteinizing hormone (LH) is an important hormone both men and women produce. This hormone is known as a Gonadotropin, and it affects the sex organs in both men and women. For women, it affects ovaries, and in men, it affects the testes. LH plays a role in puberty, menstruation, and fertility.

12. Ovulation is a phase in the menstrual cycle. It occurs at about day 14 of a 28-day menstrual cycle. Specifically, ovulation is the release of the egg (ovum) from a woman's ovary.

13. During days 12–14, however, estrogen provides positive feedback to the hypothalamus and pituitary gland. This causes a rapid rise in the production of estrogen by the ovaries and leads to ovulation.

14. As well as playing a secondary role in follicular responsiveness to FSH, LH is the trigger for ovulation itself. In response to the switch in estrogen mediated feedback from negative to positive, the LH mid-cycle surge is created.

15. Feedback occurs when outputs of a system are routed back as inputs as part of a chain of cause-and-effect that forms a circuit or loop. The system can then be said to feed back into itself.

(God bless ^_^, research nalang kung need, hehe).