Question

Read the given passage and answer the question below.

The reproductive cycle, in female primates, called the menstrual cycle, comprises 28 days in a healthy female. Primata is the order to which monkeys, apes and human beings belong. The duration of the menstrual cycle varies in different females as it is dependent upon a number of factors. However, the average duration amounts to around 28 days.

Which of the following is the correct sequence of menstrual cycle?
[1 mark]

• A. Menstrual phase $\to$ follicular phase $\to$ ovulatory phase $\to$ luteal phase
• B. Menstrual phase $\to$ ovulatory phase $\to$ secretory phase $\to$follicular phase
• C. Follicular phase $\to$ menstrual phase $\to$ ovulatory phase $\to$secretory phase
• D. Ovulatory phase $\to$ bleeding phase $\to$ secretory phase $\to$follicular phase

Answer 1

The correct option is A Menstrual phase $\to$ follicular phase $\to$ ovulatory phase $\to$ luteal phase

Menstrual phase (bleeding phase) marks the beginning of the menstrual cycle and hence, the first day of this phase is considered day 1 of the menstrual cycle.

It is followed by the follicular phase (proliferative phase) in the ovary during which the Graafian follicle matures. The endometrium becomes thicker by an increase of uterine glands and blood vessels.

Ovulatory phase basically denotes the phase of ovulation i.e., the rupture of the Graafian follicle under the influence of LH results in the release of secondary oocyte (luteinizing hormone).

Luteal or secretory phase is the post ovulatory phase i.e., it occurs after ovulation during which the uterine lining keeps thickening in anticipation of receiving the zygote in case fertilisation occurs. Around the 28th day of the cycle, this phase comes to an end and is followed by the disintegration of the endometrium leading to the menstrual phase (bleeding phase) of the next cycle.

Hence the correct sequence of menstrual cycle is as follows :

Menstrual phase $\to$ follicular phase $\to$ ovulatory phase $\to$ luteal phase