Question

Which one of the following events is correctly matched with the time period in a normal menstrual cycle?

• A. Release of egg- $5^{th}$ day
• B. Endometrium regenerates- 5 - 10 days
• C. Endometrium secretes nutrients for implantation- 11 - 18 days
• D. Rise in progesterone level- 1 - 15 days

Answer 1

The correct option is B Endometrium regenerates- 5 - 10 days

Menstrual cycle is divided into three phases: follicular, ovulatory and luteal.

1. During 1-4 days of follicular phase, there is low secretion of Follicle stimulating hormone (FSH) and Luteinizing hormone (LH). Primary follicles grow and outer two thirds of endometrium shed off.

2. During 5-13 day of follicular phase, FSH secretion increases. Follicles grow and Graafian follicles develops. Mitotic division increases thickness of endometrium.

3. During ovulatory phase which occurs during 14 days, there is LH surge and increased secretion of FSH. Graafian follicle ruptures and secondary oocyte is extruded into uterine tube. The ovulation occurs on 14th day. There is no change in Endometrium.

4. During luteal phase which occurs during 15-28 days, LH and FSH decrease. There is development of Corpus luteum and glandular development in endometrium due to progesterone stimulation.

Hence, the correct option is option B stating the regeneration of Endometrium in 5-10 days i.e. during follicular phase.

So, the correct answer is 'Endometrium regenerates- 5 - 10 days'.