Answer to Question #90581 in Cell Biology for Aahmad

Question

Which of the following statements accurate?

FSH and LH stimulation of estrogen production follicles is an example of negative feedback.

Hormone levels produced during the menstrual cycle are under the influence of both positive and negative feedback machanisms.

The corpus luteum will degenerate in the absence of FSH

Estrogen and progesterone inhibition of the release of GnRH, FSH, and LH is an example of a positive feedback mechanism.

Answer 1

The accurate statement is:

Hormone levels produced during the menstrual cycle are under the influence of both positive and negative feedback mechanisms. 

Due to the negative feedback, rising level of hormones gives feedback to the hypothalamus and pituitary gland to decrease the production of hormones. Due to the positive feedback, rising level of hormones gives feedback to hypothalamus and pituitary gland to increase the hormone production. During most of the menstrual cycle, estrogen and progesterone gives negative feedback to the hypothalamus and pituitary gland. This keeps their levels more or less constant. 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. During the second half of the cycle, progesterone rises as the corpus luteum in the ovary matures and produces this hormone. Negative feedback helps keep levels of the other three hormones fairly constant.