Which one of the given statements is correct regarding hormonal changes during menstrual cycle?
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → Both LH and FSH attain peak level in the middle of the cycle.
The menstrual cycle has a menstrual, a follicular, an ovulatory and a luteal phase. LH (luteinising hormone) and FSH (follicle stimulating hormone) are made by the pituitary gland and control the changes in the ovary.
(1) LH and FSH gradually increase during luteal phase of the cycle. — Incorrect. They rise gradually in the follicular phase. In the luteal phase the corpus luteum secretes large amounts of progesterone, and LH and FSH do not keep rising.
(2) LH attains peak level in the luteal phase of the menstrual cycle. — Incorrect. The LH peak comes in the middle of the cycle, before the luteal phase begins.
(3) Both LH and FSH attain peak level in the middle of the cycle. — Correct. Both peak at about the 14th day. The rapid rise of LH, called the LH surge, breaks the Graafian follicle and releases the ovum (ovulation).
(4) LH and FSH gradually decrease during follicular phase of the cycle. — Incorrect. They increase gradually in this phase. This increase makes the follicles grow and secrete estrogens.
NCERT Extract:
Menstrual Cycle – “… The secretion of gonadotropins (LH and FSH) increases gradually during the follicular phase, and stimulates follicular development as well as secretion of estrogens by the growing follicles. Both LH and FSH attain a peak level in the middle of cycle (about 14th day). Rapid secretion of LH leading to its maximum level during the mid-cycle called LH surge induces rupture of Graafian follicle and thereby the release of ovum (ovulation).”
