Question
Which of the following correctly represents the sequence of hormonal events during the menstrual cycle?
(A) FSH → Estrogen → LH surge → Ovulation → Progesterone (B) LH → FSH → Progesterone → Estrogen → Ovulation (C) Estrogen → FSH → LH surge → Progesterone → Ovulation (D) FSH → LH surge → Estrogen → Ovulation → Progesterone
(NEET 2023 pattern — hormonal sequencing)
Solution — Step by Step
The 28-day menstrual cycle has three distinct phases: follicular (days 1–13), ovulatory (day 14), and luteal (days 15–28). Every hormone question becomes trivial once you pin each hormone to its phase — so draw this timeline in your rough sheet before attempting.
The anterior pituitary releases FSH (Follicle Stimulating Hormone) at the start of the cycle. FSH stimulates the primary follicles in the ovary to grow and mature. As the follicle develops, the granulosa cells surrounding it begin secreting estrogen — this is a cause-effect chain you must commit to memory: FSH → follicle growth → estrogen rise.
Rising estrogen levels eventually cross a threshold and trigger a positive feedback on the pituitary — this is the one place in the cycle where estrogen causes more hormone release, not less. The pituitary responds with a massive spike of LH (Luteinizing Hormone) around day 13. This LH surge causes the mature Graafian follicle to rupture and release the secondary oocyte — this is ovulation on day 14.
After ovulation, the ruptured follicle doesn’t just disappear. Under continued LH stimulation, it transforms into the corpus luteum. The corpus luteum now becomes a temporary endocrine gland, secreting large amounts of progesterone (and some estrogen). Progesterone’s job: prepare the uterine endometrium for implantation.
The correct sequence is: FSH → Estrogen → LH surge → Ovulation → Progesterone
This matches Option (A).
Why This Works
The entire hormonal cascade is built on two feedback loops working in opposite directions. In the follicular phase, rising estrogen initially suppresses FSH (negative feedback) — this ensures only the dominant follicle survives while others undergo atresia. Then, once estrogen crosses its peak threshold near day 13, it flips to positive feedback and triggers the LH surge.
This positive feedback is the conceptual keystone of the whole chapter. NEET examiners love testing it because most students assume hormones always work by negative feedback. Progesterone, secreted by the corpus luteum, acts by negative feedback to suppress both FSH and LH in the luteal phase — preventing a new follicle from developing while pregnancy is possible.
If fertilisation doesn’t occur, the corpus luteum degenerates into the corpus albicans around day 26-27. Progesterone and estrogen fall sharply, the endometrium breaks down, and menstruation begins — starting the cycle again.
Alternative Method — The “Phase → Gland → Hormone” Framework
When a NEET question gives you a hormone and asks what happens next, use this three-column mental table:
| Phase | Gland/Structure | Hormone Released |
|---|---|---|
| Early follicular | Anterior pituitary | FSH |
| Mid follicular | Ovarian follicle (granulosa) | Estrogen |
| Late follicular (day 13) | Anterior pituitary | LH surge |
| Day 14 | — | Ovulation |
| Luteal | Corpus luteum | Progesterone + Estrogen |
| Day 28 (no pregnancy) | Corpus luteum degenerates | All levels drop → menstruation |
Work backwards from any hormone name to its source gland, then ask: what phase is that gland active in? This eliminates wrong options in under 30 seconds.
Common Mistake
Confusing which feedback is positive vs. negative.
Most students write: “Estrogen always causes negative feedback on the pituitary.” That’s only true early in the cycle. Near peak estrogen (day 13), the feedback inverts to positive — this is the LH surge mechanism. If you apply negative feedback throughout, you’ll never be able to explain how LH spikes just before ovulation.
In NEET 2023 and several previous papers, one option is specifically designed to trap students who assume negative feedback at all estrogen levels. Memorise this: low estrogen = negative feedback; peak estrogen = positive feedback → LH surge.
The “28-day rule” for quick recall: Menstruation (days 1–5), follicular (days 1–13), ovulation (day 14), luteal (days 15–28). Weightage for this topic in NEET is consistently 2–3 questions per year. Learn the corpus luteum → corpus albicans fate because NEET 2022 asked it directly as a standalone question.