Question

Which of the following statements is correct regarding menstrual cycle?
a. LH induces rupturing of graafian follicle.
b. Proliferative phase is characterised by the increased production of progesterone.
c. Corpus luteum secretes a large amount of estrogen.
d. Both LH and FSH attain a peak level in the secretory phase.

Answer 1

Hint: Menstrual cycle is a series of events that happens in the female reproductive system and this is responsible for the pregnancy to be possible. It prepares the uterus for the maintenance of a potential embryo. There are a number of hormones that control the whole process of menstrual cycle in primates. It usually lasts for 28-29 days.

Complete answer:
Let us first broadly see and understand what are the different phases that are present in the menstrual cycle. Menstrual cycle is broadly divided into four phases. They are the menstrual phase, follicular phase, ovulation phase and the luteal phase. Lets see them one by one.

A. First let's see about the menstrual phase. The menstrual cycle begins with the menstrual phase. The menstrual phase is the phase when the menstruation or the shedding of the uterine wall happens. This happens when there is no fertilisation. Many women face cramps in the lower abdomen during this phase. Estrogen levels are high in this phase.

B. Next let's see about the follicular phase In the follicular phase, the follicles mature and get ready to release the egg. A mature follicle that dominates and releases the egg is called the graafian follicle. In the follicular phase, the level of Follicle Stimulating Hormone (FSH) is very high.

C. Next let's see what happens in the ovulatory phase. The phase where the egg is released from the mature graafian follicle is called the ovulatory phase and this happens during the 14th day of the menstrual cycle. The level hormone LH goes very high and this causes the egg to be released. This rise in LH is called ‘LH surge’.

D. The last phase is the luteal phase. In the luteal phase, the level of LH and FSH comes down. The remnant of the graafian follicle is called the corpus luteum which produces progesterone.

Hence, the correct answer is option (A).

Note: Some authors say that there are two cycles in the menstrual cycle and they are ovarian cycle and the uterine cycle. The uterine cycle consists of menstrual phase, proliferative phase and secretory phase. And the ovarian cycle consists of the menstrual phase, proliferative phase and the secretory phase.
Menstrual cycle is exclusively seen in primates. The other non-primate animals have estrous/oestrous cycles.