About which day in a normal human menstrual cycle does rapid secretion of LH (Popularly called LH-surge) normally occurs

Options

A. `5^("th")` day
B. `11^("th")` day
C. `14^("th")` day
D. `20^("th")` day

Answer

**Step-by-Step Solution:**

1. **Understanding the Menstrual Cycle**: The normal human menstrual cycle lasts about 28 days. It consists of different phases, including the follicular phase, ovulation, and luteal phase.

2. **Identifying the Ovulation Phase**: Ovulation is the process where a mature egg is released from the ovary. This typically occurs around the midpoint of the menstrual cycle.

3. **Timing of Ovulation**: In a standard 28-day cycle, ovulation usually occurs around day 14. This is when the luteinizing hormone (LH) reaches its peak level.

4. **LH Surge**: The rapid secretion of LH, known as the LH surge, is crucial for triggering ovulation. It is this surge that causes the mature follicle to release the secondary oocyte.

5. **Conclusion**: Therefore, the rapid secretion of LH, or LH-surge, normally occurs on the 14th day of the menstrual cycle.

**Final Answer**: The rapid secretion of LH (LH-surge) normally occurs on the 14th day of a normal human menstrual cycle.

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