Question

Ovulation takes place in a month during

• A. 11-14 days
• B. 14-16 days
• C. 15-28 days
• D. 21-26 days

Answer 1

Answer: (B)

14-16 days

The menstrual cycle can be divided into four phases: menstruation, proliferative, ovulatory and secretory phase.

Day 1 - 5 (menstruation phase) experience lower estrogens and progesterone level, which in turn results in disintegration of endometrium and menses.

Day 5 - 13 (proliferative phase) is marked by endometrium thickening under the influence of estrogens as secreted by developing follicle. Day 11-14 comes under proliferative phase. Proliferative phase is followed by ovulation, i.e., rupture of mature Graafian follicle and release of an ovum in the body cavity, which is regulated by higher LH levels.

Ovulation occurs on 14${}^{th}$ day of 28 days cycle. Ovulation is followed by the secretory phase in (day 15 - 28), which is marked by uterine endometrium thickening under the influence of progesterone as secreted by corpus luteum, to prepare it for implantation. Thus, the correct answer is option B.