In the 28 day human ovarian cycle the duration of luteal phase is approximate ?

Options

A. 14 days
B. 28 days
C. 30 days
D. 5 days

Answer

To determine the duration of the luteal phase in the 28-day human ovarian cycle, we can break down the cycle into its phases:

1. **Understanding the Ovarian Cycle**: The ovarian cycle consists of four main phases: the menstrual phase, the follicular phase, ovulation, and the luteal phase.

2. **Phases of the Ovarian Cycle**:
- **Menstrual Phase**: This phase starts on day 1 and typically lasts until day 5 or 6.
- **Follicular Phase**: This phase occurs from day 5 to about day 10. It lasts approximately 5 to 6 days.
- **Ovulation**: Ovulation occurs on day 14 of the cycle. This is a single-day event.
- **Luteal Phase**: This phase begins after ovulation and lasts until the end of the cycle, which is day 28.

3. **Calculating the Duration of the Luteal Phase**:
- The luteal phase starts on day 14 (the day of ovulation) and continues until day 28.
- Therefore, the duration of the luteal phase is from day 14 to day 28, which is a total of 14 days.

4. **Conclusion**: The approximate duration of the luteal phase in the 28-day human ovarian cycle is 14 days.

### Final Answer:
The duration of the luteal phase is approximately **14 days**.