Question

Menstrual flow begins in response to:

a. Increasing levels of FSH and LH

b. A surge of estrogen

c. Decreasing levels of progesterone

d. Decreasing levels of LH and estrogen

Answer 1

Answer is 4 th option

Menastrual flow begins in response to-

Decreasing levels of estrogens.

In menastrual cycle 1 st 5 days indicates menstrual phase, during this phase there are low levels of LH and oestrogen, FSH.

This low levels of harmones causes bleeding thereby leading to menstrual flow.

Oestrogen ,FSH levels increase during the 14 th day that is at the time of ovulation. This leads to the release of ovim from ovary.

Later LH increases( this is called LH surge) and thereby increasing progesterone levels in blood.

This progesterone helps in improving and development of the endomentrium for implantation of the zygote if the fertilization occurs.

Decreasing progesterone level is not related with menstrual flow but it indicates the end of pregnancy. And leads to the delivery of the baby.

A surge for oestrogen is on the 14 th day during ovulation period.