Introduction To Menstrual Cycle 1

Withdrawal of which of the following hormones is the immediate cause of menstruation?

1. Estrogen

2. FSH

3. FSH-RH

4. Progesterone

In the human female, menstruation can be deferred by the administration of:

1. LH only

2. Combination of FSH and LH

3. Combination of estrogen and progesterone

4. FSH only

Which one of the following is the correct match of the events occurring during the menstrual cycle?

1.	Ovulation - LH and FSH attain peak level and sharp fall in the secretion of progesterone
2.	Proliferative phase - Rapid regeneration of myometrium and maturation of Graafian follicle
3.	Development of corpus luteum - Secretory phase and increased secretion of progesterone
4.	Menstruation - Breakdown of myometrium and ovum not fertilized

Given below are two statements: one is labelled as Assertion (A) and the other is labelled as Reason (R).

Assertion (A):	Endometrium is necessary for implantation of blastocyst.
Reason (R):	In the absence of fertilization, the corpus luteum degenerates that causes disintegration of endometrium.

In the light of the above statements, choose the correct answer from, the options given below:

1.	(A) is False but (R) is True.
2.	Both (A) and (R) are True and (R) is the correct explanation of (A).
3.	Both (A) and (R) are True but (R) is not the correct explanation of (A).
4.	(A) is True but (R) is False.