MEDICAL
OVARIES AND FALLOPIAN TUBES
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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LH; positive
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LH; negative
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progesterone; postive
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progesterone; negative
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Detailed explanation-1: -The Positive Feedback Effect of Estrogen on GnRH Secretion. The positive feedback effect of estrogen is the mechanism by which the GnRH cells of the brain and the pituitary gonadotropes produce surges in the secretion of GnRH and gonadotropins, respectively, that lead to ovulation.
Detailed explanation-2: -The hypothalamus secretes GnRH in a pulsatile fashion, which triggers FSH and LH release from the anterior pituitary. These, in turn, act on the granulosa and theca cells in the ovary to stimulate follicle maturation and trigger ovulation.
Detailed explanation-3: -As circulating estrogen levels rise on the afternoon of proestrus, they stimulate the hypothalamo-pituitary axis. This estrogen positive feedback is pivotal to stimulate the luteinizing hormone (LH) surge required for ovulation and luteinization of ovarian follicles.
Detailed explanation-4: -Ovulatory Phase This peak in estrogen triggers a brief surge in Luteinizing Hormone (LH), which triggers ovulation within usually 24 hours and occasionally up to 48 hours.