LH surge occurs during which phase of menstrual cycle?

Options

A. Bleeding phase
B. Pre ovulatory phase
C. Post ovulatory phase
D. Secretory phase

Answer

### Step-by-Step Solution:

1. **Understanding the Menstrual Cycle**: The menstrual cycle in human females typically lasts about 28 days and consists of four main phases: menstrual phase, follicular phase, ovulatory phase, and luteal phase.

2. **Identifying the Phases**:
- **Menstrual Phase**: This is the first phase, lasting about 4 to 5 days, characterized by the breakdown of the endometrium and bleeding.
- **Follicular Phase (Pre-Ovulatory Phase)**: This second phase lasts from day 6 to day 13, during which the follicles mature in preparation for ovulation.
- **Ovulatory Phase**: This is the third phase, occurring around day 14, and is the shortest phase. It is during this phase that ovulation occurs.
- **Luteal Phase (Post-Ovulatory Phase)**: This final phase lasts from day 15 to day 28, during which the corpus luteum forms.

3. **Focusing on the LH Surge**: The question specifically asks about the LH (luteinizing hormone) surge, which is crucial for triggering ovulation. The LH surge occurs just before ovulation.

4. **Timing of the LH Surge**: The LH surge peaks on the 14th day of the menstrual cycle, coinciding with the ovulatory phase. This surge is responsible for the release of the egg from the ovary.

5. **Conclusion**: Therefore, the LH surge occurs during the **ovulatory phase** of the menstrual cycle. If the ovulatory phase is not listed as an option, the pre-ovulatory phase may be considered as it leads into the ovulatory phase.

### Final Answer:
The LH surge occurs during the **ovulatory phase** of the menstrual cycle.

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