The menstrual cycle is counted from the first day of bleeding. In the menstrual phase, the uterine functional endometrial layer sheds as ovarian steroid support falls. During the proliferative or follicular phase, ovarian oestrogens support rebuilding the endometrium. Around mid-cycle the LH surge leads to ovulation. After ovulation the luteal or secretory phase is dominated by corpus-luteum progesterone and glandular endometrial activity.

Without pregnancy, luteal regression reduces progesterone and oestrogen and another menstruation begins. During early pregnancy hCG supports the corpus luteum, helping sustain progesterone. The ovarian phases and uterine phases describe coordinated but distinct structures. In a graph, a rise after ovulation in the secretory phase refers to progesterone, not the chromosome number of the oocyte.

Worked example: Menstrual shedding → oestrogen-driven growth → ovulation → progesterone-supported secretory lining.

NCERT trap: Menstrual day 1 starts the cycle; post-ovulation progesterone comes largely from corpus luteum.

NEET method: Place uterine events alongside ovarian hormones, then check whether pregnancy is specified.

Reading estimate; allow another 3–5 minutes for each set of three checks.

Human Reproduction

Check 1 of 3

Check 2 of 3

Check 3 of 3

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